 Picture credit: NASA. John writes … This blog has been inspired (if that’s the right word) by several intersecting lines of thought. Firstly, I started writing this on Earth Day, a ‘commemoration’ established in 1970 to mark the ‘birth of the modern environmental movement’ (www.earthday.org). That movement can probably be traced back to the publication of Rachel Carson’s influential book Silent Spring (Houghton Mifflin, Boston /Hamish-Hamilton, London, 1962). In the book, the author demonstrated the effects on the biosphere of the routine use/over-use of pesticides, especially DDT, showing that their damage went far beyond their original targets, partly because of the networks of interactions of different groups of living organisms. This topic was explored further in another book, Pesticides and Pollution by Kenneth Mellanby (Collins, London, 1967).
Since those days, use of the most damaging pesticides has been discontinued but human activity continues to damage the environment in different ways, of which climate change is currently the most pressing. Earth Day, with its focus on the thin layer of the planet’s surface in which life occurs (the biosphere), reminds us that Earth is the only ‘home’ that humankind has known and that although apparently independent of nature, we are still actually dependent on the way it functions. The changes in climate are already having effects on the ‘liveability’ for humans in some parts of the world, including low-lying islands. There are also clear changes in the global distribution of many living organisms, changing the ‘balance of nature’ in many locations. Further, as I indicated in an earlier post, if we continue as we are, parts of Africa, South America, Asia and Australia will become uninhabitable. Earth Day is a good opportunity to remind ourselves of this. The Internet of Living Organisms I have already hinted at the second train of thought in the previous two paragraphs. Affecting one part of an ecosystem affects the other parts because of the linkages between organisms, which function at several different levels. One example, which is very relevant to current concerns, is that a decrease in the abundance of pollinating insects, may lead to a decrease in seed production. This not only affects the reproductive success of the relevant plants but also affects those animals which use the seeds for food. This in turn may affect the reproductive success of those animals. Inter-species balances in the ecosystem will have been altered. Nor are humans immune to this. Although all our ‘staple’ cereal crops are wind-pollinated, many others, including for example, fruit crops, rely on insect pollination. This straightforward example, involving relatively short chains of interaction is actually just an indicator of a much more complex situation. I am writing this in our study/exercise room (yes, really – there is an exercise bike behind me and Swiss ball beside the desk) looking out at a beautiful group of mature trees beyond the bottom of the garden, between our row of houses and Topsham quay. Each of those is home to thousands of insects and other invertebrates, a food source for many local birds. Birds use the trees as lookout points, song-posts and nest sites. In the autumn, the hawthorns will provide berries for birds and small mammals, followed later by ivy berries: ivy is growing up several of the larger trees. And we should not forget that the dry seeds/fruit of other trees, including ash and pine, also provide food for squirrels and other small mammals such as wood mice. The trees themselves of course fix carbon through the process of photosynthesis, thus contributing positively to the local carbon budget. Further, the trees have stabilised the ground around them, providing a habitat for a particular group of non-woody plants that thrive in clearings and woodland edges.  If we go below ground, we will discover that most of the trees are in a close relationship with fungi, in the form of mycorrhizas (‘fungus-roots’). Depending on the species of tree and of fungus, these take different forms but the key feature is that the relationships are mutualistic, benefitting both tree and fungus. Further, the fungal mycelia – threads of growing fungus – extend from tree to tree providing an underground network for chemical signalling between the trees. The size of such networks can be astonishing. In a well-established forest in Sweden between 60,000 and 1.2 million ectomycorrhizas were present in one square metre of soil, with the mycelia of each fungal individual extending up to 100 square metres (Mycorrhizas - the wood wide web | Trees for Life). If anyone is interested in finding out more about this world beneath our feet - the ‘Wood-wide Web’ - I recommend Merlin Sheldrake’s excellent book Entangled Life (Random House, London and New York, 2020).  Fly Agaric toadstool in a small wood in North Yorkshire. The toadstool is the fruiting body produced by an extensive underground fungal mycelium. I hope that by now, readers will appreciate why I often refer to the biosphere as the internet of living things. With that in mind, I want to return to a topic mentioned briefly above, namely pollination but I will re-introduce it by a slightly circuitous route. Ten years ago, the community of Topsham was fortunate in being able to purchase a parcel of land (2.4 hectares/ 6 acres) beside the river at the south end of the little town. The land, which includes a small copse, is managed as a semi-wild open space, completely free to access. One of my roles on the management committee is to survey ‘biodiversity’, keeping a monthly record of the main features. Thus, this month I have been very pleased to see so many Arum lilies (Arum maculatum) in flower in the copse. This plant is famous for temporarily trapping flies within its flower. Flies are attracted to the plant by the warmth of a part of the flower called the spadix, crawl down into the flower and are trapped therein by the springy hairs (the biochemistry of heat generation in plants is an interesting topic in its own right, but lies outside the scope of this post). While feeding there, the flies become dusted with pollen, the springy hairs wilt, releasing the flies which then repeat the process with another Arum plant. Pollen is thus transferred from plant to plant.  Arum flower.  Cartoon of the Arum pollination mechanism. Redrawn from Lords and Ladies (C.T. Prime, Collins, 1960) and published in Functional Biology of Plants (M.J. Hodon and J.A. Bryant, Wiley-Blackwell, 2012). Because plants are static within the environment, individuals cannot move around to find mates in order to bring the male gametes (pollen) into contact with the female gametes (ova/eggs). So, unless self-fertilisation becomes the norm, an agent is needed, as exemplified by the flies in the previous paragraph. Our current understanding is that the very earliest flowering plants were pollinated by insects, probably beetles. We do not know what attraction mechanisms were ‘employed’ by these early flowering plants – perhaps it was just the flower itself. However, over the subsequent 130 million years, flowering plants have multiplied, evolved and diversified. There are now about 300,000 species ranging hugely in shape and size. The majority (85%) are pollinated by animals, mainly insects (although some are pollinated by vertebrates, including birds, bats, small mammals and even lizards). The other 15%, which includes many trees, and all grasses and cereals, are pollinated by wind or in rare instances, water.  For insect pollination, we can see that a variety of attraction mechanisms have evolved over the history of flowering plants. The plant provides a source of protein (the insects consume some of the pollen) and many cases also a source of sugar in the form of nectar. As mentioned already, the flower itself may be part of the attraction mechanism while many plants also produce floral scents. In some species which are pollinated by night-flying insects such as moths, those scents are produced in the hours of dusk and darkness. We can thus see that many flowering plants produce chemicals that are not needed for the general life of the plants themselves, namely nectar and scented molecules, but are needed to attract pollinators. But it is not all a one-way street: many, perhaps even a majority of the insects which pollinate flowering plants are dependent on them for sources of sugar and protein. Just as the mycorrhizal fungi and their hosts are co-dependent, so are these flowering plants and their pollinators. This introduces us to my third line of thought, concerning co-evolution, where natural selection favours / has favoured those variants in which relationships between different organisms are strengthened. The general inter-dependence of many plant species with many insect species is an example of this: flowering plant and insect evolution have been tightly linked over millions of years. However, there are some examples in which the linkage is even tighter, where the interactions are very specific. For the sake of space, I will give just one example, that of plants in the Yucca family, the most well-known of which is the Joshua Tree. I wrote about this in the book itself (pp. 183-184) but the story is so remarkable that I am happy to re-tell it here. Yucca plants are pollinated by Yucca moths, with each species of moth having a very strong preference for just one species of Yucca. The inter-dependence between plant and moth is so strong that one cannot live without the other (see Yucca Moths). I will start the story with the emergence from their pupae of the adult moths. This occurs in Spring and is synchronised with the flowering of the relevant Yucca species. Male and female moths encounter each other on the flowers and then mate. The male’s job is done and he soon dies. However, the female collects pollen from the anthers of the flower and gathers it into a ball under her ‘chin’. She then visits another plant and lays a few eggs in its ovaries. The emphasis here is on ‘few’ – too many would cause the flower to abort. She then does something which, even though I know the facts, I still find incredible. The female does not consume any of the ball of pollen she collected from the first plant. She does not need to eat because she will shortly die. Instead, she removes the pollen and scrapes it onto the stigma of the flower in which she has laid eggs. In effect, the female moth acts as a pollen carrier for the plant, with the reward of a safe place to lay her eggs. The plant’s ova are thus fertilised, ensuring that seeds will be formed. Some of these, as they develop, will provide food for the moth’s growing caterpillars but since there are only a few caterpillars (remember that only a few eggs were laid) several seeds survive to maturity and ripen. Alongside them, the caterpillars also reach maturity, leave the flower and go down to the ground to pupate. The pupae will remain in the ground until the following Spring when the new generation of adult moths emerges to start the sequence all over again. This is an amazing example (and there are others) of a rigid inter-dependence of two totally unrelated organisms.  Joshua tree. In addition to the range of strong interdependencies in nature there are also examples where one side or the other has evolved in such a way that it ‘games the system’. One of my favourite examples of this is the Bee Orchid, the flowers of which somewhat resemble female bees. These attract male bees which attempt to mate with the flowers. In doing so, they pick up pollen but leave without the apparently promised ‘reward’ of a successful mating. When the male attempts to mate with another flower, some of that pollen will be transferred, thus ensuring a successful pollination of the second flower. In this instance, the plant is dependent on the bee but the bees need to mate is exploited without being met.  Bee orchid. The interactions and inter-dependencies I have described here are snapshots from a highly interconnected biosphere. In respect of any of the damaging aspects of human activity, one question that I want to highlight concerns selective effects on particular components of networks. What happens if one member of a partnership is more affected by pollution or climate change than others? We can see straightaway that the well-established ‘balance of nature’ can all too readily become unbalanced. This should concern us.
Final thought I started this post by discussing Earth Day and I want to say a little more about this. Christians – and indeed, Jews and Muslims - believe that our beautiful planet is the work of God the creator. Psalm 24, verse 1 puts it like this ‘The earth is the Lord’s, and everything in it, the world, and all who live in it’ In effect we live on Earth as tenants or stewards with a responsibility to care for it. I was therefore very taken with the words of Professor Katherine Hayhoe, an American Christian climate scientist, when she wrote on her website, ‘Isn’t every day Earth Day?’ (https://www.talkingclimate.ca). Let’s act on that. As always, if you have any thoughts on what I have said in this post, please leave a comment below. Thank you. John Bryant Topsham, Devon April 2025 Picture credits: the copyright of all images is owned by the author, unless otherwise stated.
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Graham writes …  In a blog post in October 2023, I discussed the potential discovery of possible extraterrestrial life, and I signed off by saying that the research findings were not the last word on the topic, and to expect an update at some point in the future. This brief blog is that update, in which I discuss recent developments in this intriguing story. If you would like to know the full details of what was going on in 2023, you can read my previous blog by just clicking on ‘October 2023’ on the archive list on the right-hand side of this page. But if you don’t have the time or the inclination to do that, then briefly the story goes like this … In 2023 one of the spectroscopy instruments aboard the James Webb Space Telescope (JWST) was brought to bear on the atmosphere of an exoplanet called K2-18b located 124 light-years away in the constellation Leo. This planet is classified as a "Hycean" world – a type of exoplanet characterized by a hydrogen-rich atmosphere with a potential global ocean beneath. Previous JWST observations had already identified methane and carbon dioxide in its atmosphere, supporting the idea of a habitable environment. However, the thing that really sparked media interest was the detection of a molecule called dimethyl sulfide (DMS) in K2-18b’s atmosphere. Here on Earth, the only natural mechanism for producing this is its production by marine micro-organisms such as phytoplankton. Its presence in an exoplanet's atmosphere is considered a potential biosignature, indicating possible biological activity. Last week (week beginning 14 April 2025) the main stream media caught up with this story, and went completely bonkers, implying that the JWST had discovered ET, complete with clips from films like Close Encounters of the Third Kind! Which is the reason why I’m led to write this – to calm the situation a little and to say what we have actually found in these new results.  Artist's impression of exoplanet K2-18b. Credit: A Smith and N Mandhusudhan, University of Cambridge. The previous JWST data were acquired using an instrument which used a particular band of the infra-red (IR) spectrum in which DMS was degenerate with other atmospheric species. In other words, the ‘bump’ in the spectrum produced by DMS was coincident with the spectral features of the other gases, so introducing a difficult ambiguity into the analysis. The results showed that there was a one in 60’ish chance that the detection of DMS was a statistical fluke. Hence, the conclusion that it was a marker for life was not secure.  James Webb Space Telescope in a clean room environment. Credit: NASA So what’s new? The recent results were reported in April 2025 by astronomers at Cambridge University, UK, led by Dr. Nikku Madhusudhan. These were acquired by an alternative spectroscopy instrument aboard the JWST which uses a different bandwidth, deeper in the IR spectrum. In this part of the spectrum the ambiguity in detecting DMS is less, and its signature persisted giving a result at around the 3-sigma level (in statistician’s speak). This means that there is approximately a one in 300’ish chance that the DMS detection is a statistical fluke. This is obviously a great improvement on the previous findings, but still not cast-iron proof. To acquire that kind of confidence, then more work needs to be done to reach a 5-sigma result – that is, the chance of a fluke is around one in a million. Finally, and very significantly, there is also the prospect that DMS may be produced through abiotic chemical pathways, with which we are presently unfamiliar. The story continues …
To tell the tale in a more measured and authoritative way, please see this short YouTube video presented by the lead scientist at Cambridge University, Dr. Nikku Madhusudhan. Graham Swinerd Southampton, UK April 2025 Graham writes ...  The analysis of samples collected from asteroid Bennu by NASA's OSIRIS-REx mission has yielded significant insights into the origin of the building blocks of life and the conditions prevailing in the early solar system. The first results from the analysis were published recently in early 2025 (1,2,3), suggesting that the biochemistry that makes up our DNA may have occurred off-world, and perhaps even long before the Earth existed. Talking more generally, it’s fair to say that we have only the sketchiest of ideas of how life began on Earth, which of course makes it difficult to say much about life elsewhere. One encouraging detail in our search for understanding, however, is how quickly life started on Earth. The earliest fossils are believed to be dated only a few hundreds of millions of years after Earth’s formation and cooling. Given that this is a relatively short period of time for natural selection to produce the first single cell organism, some view this as evidence for panspermia – that is, that life didn’t have its origins on Earth, but started in space. This is not a new idea – it was first proposed in 1972 by Nobel laureate Francis Crick, along with Leslie Orgel, who suggested that life was deliberately brought to Earth by a higher intelligence from another planet! Maybe life didn’t start in space, but the results from the OSIRIS-Rex samples are pointers to the idea that life’s building blocks did.  Bennu, is a carbonaceous asteroid about 500 metres across occupying an Earth orbit-crossing trajectory. Credit: NASA. There has been much evidence of this point of view, obtained from the analysis of things that have fallen to Earth from space. The most important example of this is the Murchison meteorite which fell in 1969 in Australia – the ‘Shire of Murchison’ is a local government area in Western Australia. This was dated to be about 7 billion years old and contained 90 different amino acids, many more than the 20 which form the basis of life on Earth. Another interesting feature was that the Murchison amino acids came in both left-handed and right-handed varieties (both ‘mirror reflections’), whereas Earth-life amino acids are all left-handed. So, there is clearly significant evidence that not all the amino acids found in the meteorite were due to contamination by the terrestrial environment.  OSIRIS-REx spacecraft during assembly, integration and test in a clean room environment. Credit: NASA. However, the best way to ensure no contamination is to acquire samples directly from space and store them in an inert environment (usually involving immersion in nitrogen) during transit. There are a number of examples of this, prior to the current OSIRIS-Rex mission, including:
As an interesting aside, the various amino acids comprise different configurations of H, C, N and O atoms, indicating that the nebula from which the solar system formed contained heavy stars that had an explosive ending, thus ensuring the presence of the heavier elements – which in turn ensured that the Sun’s planetary system was ripe in its potential to produce complex life. Coming back to NASA’s current mission OSIRIS-Rex (the name is a convoluted acronym that I will not repeat here …), the spacecraft landed on asteroid Bennu on 20 October 2020. This object is an ordinary carbonaceous asteroid about 500 metres across, which I have to say looks like a pile of rocky debris held to together by very weak gravity. It occupies an Earth orbit-crossing trajectory, which makes the astrodynamics relatively easy to enable visits. The spacecraft touched down on Bennu and samples were collected and returned to Earth, arriving home in September 2023.  The operational configuration of the OSIRIS-REx spacecraft (computer graphics rendition). Credit: NASA. Analysis of the samples indicated the presence of 14 of the 20 amino acids that Earth life harnesses in the production of proteins. However, the major surprise this time was the discovery of all five nucleotide bases G (guanine), C (cytosine), A (adenine), T (thymine) and U (uracil). As you may know these bases comprise the basic ‘alphabet’ of the genetic code, with GCAT occurring in DNA, and the same in RNA but with the base U taking the place of T. This result suggests that the biochemistry that makes up our DNA may have occurred in space, and perhaps in the gaseous nebula long before the creation of the solar system!  Recovery of the sample re-entry capsule in the Utah desert. Credit: NASA. Other findings in the analysis of the Bennu samples also point to an interesting scenario for the origin of Bennu itself, although some would consider the proposed creation narrative to be somewhat speculative. Various compounds were identified in the analysis, including a surprising richness of ammonia – 12 times higher than in the Murchinson meteorite. This is unexpected as Bennu orbits too close to the Sun to preserve pure ammonia, so this concentration hints at a colder, more distant origin. Also, eleven different minerals were recognised that we know form when brine slowly evaporates. This suggests that the stuff that comprises Bennu was once in an aqueous, salty environment. These, and other clues, led the analysis team at NASA to propose a notional origin account for the asteroid. Briefly, this suggests the formation a protoplanet comprised of rock, metals and ice in the cold outer reaches of the early solar system. As radioactive elements produced in ancient supernovae explosions decayed within, the resulting generation of heat melted some of the ice, creating pockets of mineral-rich liquid water. The chemistry that the Bennu samples reveal suggests that interactions within these ancient waters began the formation of organic molecules. However, in this story, the proposed protoplanet is doomed – a catastrophic collision, perhaps with a similar body, scatters its fragments into space and Bennu, and presumably many other asteroids, formed by the action of gravity from the debris.  A few hundred grams of 'star dust' returned by OSIRIS-REx. Credit: NASA. This remarkable story, extrapolated from the a few hundred grams of material brought back to Earth by OSIRIS-REx, has credence. Pseudo-panspermia – the idea that the chemistry of life got a kick start from space molecules is supported by the findings of this mission, and other similar spacecraft missions. But does it tell us anything about the origin of life, and the likelihood of life elsewhere? You could ask if a random pile of computer components will inevitably lead to the creation of my laptop. Of course not. The process from the random pile to the laptop is a significant one, requiring the ‘intelligent’ intervention of a skill technician. Similarly, the step from the building blocks of life to the complexity of life as we know it here on Earth could be argued to be of very much greater complexity. So, the process of abiogenesis leading to the diversity of life on Earth remains shrouded in mystery – a humbling and puzzling thought to finish on.
The story of this part of OSIRIS-Rex’s mission is given in more detail in a splendid Youtube video created by Astrum which can be viewed here. As always, if you have any thoughts on what I have said in this post, please leave a comment below. Thank you. Graham Swinerd Southampton, UK March 2025 (1) Life’s ingredients have been found in samples from asteroid Bennu / Science News. (2) Abundant ammonia and nitrogen-rich soluble organic matter in samples from asteroid (101955) Bennu / Nature. (3) Asteroid Bennu samples found to contain five nitrogenous bases crucial to supporting life / PHYS.ORG. John writes ...  Embryo development. Credit: onlinebiologynotes.com Introduction It makes me feel very old when I realise that Louise Brown, the first baby to be born via in vitro fertilisation (IVF), will be 47 years old on July 25th this year. Since her birth in 1978, over 10 million IVF-conceived babies have been born worldwide, of whom about 400,000 have been in the UK. Over that period, success rates have increased such that in some clinics, about 50% of IVF cycles lead to a live birth. At the same time, there have also been very significant advances in genetics, genomics and stem cell biology all of which, in relation to human embryos, raise interesting and sometimes challenging ethical issues. A brief diversion: non-human IVF I will return to the ethical issues later in this article but for now I want to look beyond the field of human fertility and out into the wider animal kingdom. IVF and related techniques have been used extensively in breeding of farm animals but more recently have been applied to wild animals. Thus, my eye was caught by a headline in The Guardian: ‘Australian scientists produce kangaroo embryos using IVF for first time’ (1). The scientists who did this say that their intention is not to produce hundreds of ‘joeys’ but, having shown its feasibility, to use the technique with endangered marsupial species, including koalas, Tasmanian devils and northern hairy-nosed wombats. Actually, this was far from being the first application of IVF with wild animals, as is evident from an earlier Guardian article (‘Rewinding human mistakes’: can IVF save the world’s most threatened species?) (2). There is a hint of ethical discussion here too – science is being used to undo some of the deleterious effects of human activity, albeit mainly in respect of the ‘poster boys’ of biodiversity conservation.  Scientists Dr Patricio D Palacios and Dr Andres Gambini from the University of Queensland who have carried out IVF with kangaroos. Credit: Andres Gambini.  Tasmanian Devil. Credit: Getty Images. Genetics, ethics and human embryos Returning to my main theme, I start with a question: What is the ‘moral status’ of the early human embryo? Whether the embryo arises by normal fertilisation after sexual intercourse or by IVF, there is a phase of a few days during which the embryo is undergoing the earliest stages of development but has not yet implanted into the wall of the uterus; the prospective mother is not yet pregnant. In UK law, based on the Human Fertilisation and Embryology Act (1990), these early embryos are not regarded as human persons but nevertheless should be treated with some respect. Nevertheless, as I have discussed elsewhere, there are some who oppose this view and believe that from the ‘moment of conception’ (there actually isn’t such a thing – fertilisation takes several hours) embryos should be treated as persons. In ‘conventional’ IVF this debate is especially relevant to the spare embryos that are generated during each IVF cycle and which are stored, deep-frozen, in increasing numbers for possible use in the future. A further dimension was added to this area of debate when it became possible to test IVF embryos for the presence of genetic mutations that cause disease. This process is called pre-implantation genetic diagnosis (PGD) (3) and enables prospective parents who are at known risk of passing on a deleterious mutation to avoid having a child who possesses that mutation. But what about the embryos that are rejected? They are usually discarded or destroyed but some are used in research. However, those who hold a very conservative view of the status of the early embryo will ask what right we have to discard/destroy an embryo because it has the ‘wrong genes’. And even for the many who hold a less conservative view, there are still several questions which remain, including ‘which genetic variants should we be allowed to select against?; should we allow positive selection for genes known to promote health in some way?’; should we allow selection for non-therapeutic reasons, for example, sporting prowess?’ These questions will not go away and there are already indications that non-therapeutic selection is being offered in a small number of countries.  A cell being removed from an eight-cell human embryo in order to carry out pre-implantation genetic diagnosis/testing (PGD/T). (Note that sampling one cell at this stage had been the method most widely used for many years but now, many practitioners take more than one cell from a later-stage embryo). Credit: unknown.  British long-distance runner and multiple champion, Mo Farah. We already know of several genes that are involved in the stamina and muscular activity which contribute to long-distance running ability. In theory, these genes could be looked for via PGT in order to select an embryo which had at least the ‘right genes’ to become a long-distance runner. Credit: playersbio.com. This leads us on to think about altering human genes. Initially, the issue was genetic modification (GM) which in general involves adding genes. Readers of this blog and/or my writing elsewhere will already be aware that GM techniques have been used very successfully in curing several conditions, including congenital severe immune deficiency and as part of treatment programmes for certain very difficult childhood cancers (first such case was in 2004). One key feature of these examples is that the genetic change is not passed on to the next generation – it just involves the body of someone who has already been born. Thus, we call them somatic genetic changes (from the Greek, sōmatikos, meaning ‘of the body’). Genetic modification which is passed on to the next generation is called germline GM which means that the genetic change must get into the ‘germ cells’, i.e., the sperm or egg. Currently, the only feasible way of doing this is to carry out the genetic modification on the very early embryo. At present however, with just one very specific exception, GM of human embryos is forbidden in all the countries where it would be possible to do it. There is firstly the question of deciding whether it is right to change the genetic makeup of a future human being in such a way that the change is passed to succeeding generations. Secondly, there are concerns about the long-term safety of the procedure. Although it would involve adding specific genes with known effects, the complexity of genetic regulation and gene interactions during human development means that scientist are concerned about the risks of unforeseen effects. And thirdly, germline GM emphasises dramatically the possibility of using GM for enhancement rather than for medical reasons. This leads us to think about genome editing. In 2011, it was shown that a bacterial system which edits the genomes of invading viruses could also work in other organisms (4). Further modification and sophistication of the technique has opened-up a large array of applications in research, agriculture and medicine; some of the latter have been previously discussed in this blog. However, the ethical issues raised by genome editing are, in essence, the same as raised by GM and so there is still a universal prohibition of using the technique with human embryos: germline genome editing is forbidden. Despite this, a Chinese medical scientist, He Jiankui, announced in 2018 that he had edited the genomes of several embryos, making them resistant to HIV; two babies with edited genomes had already been born while several more were on the way. The announcement caused outrage across the world, including in China itself. He Jiankui was removed from his job and then, after a trial, was imprisoned for three years. His two colleagues who collaborated in this work received shorter sentences. At present the universal prohibition of human germline genome editing remains in place. However, the discussion has been re-opened in a paper by an Anglo-Australian group who suggest that we need to develop heritable (i.e. germline) polygenic genome editing in order to reduce significantly an individual's risk of developing degenerative diseases, including coronary artery disease, Alzheimer’s disease, major depressive disorder, diabetes and schizophrenia (5). I note in passing that one of the authors is Julian Savulescu at Oxford who is already well-known for his view that parents who are able to do so, are ‘morally obliged’ to seek to have genetically enhanced children, whether by PGD, GM or genome editing (6). The use of polygenic editing, which would, in all likelihood, be available only to the (wealthy) few, fits in well with his overall ethical position. Needless to say, the paper, published in the prestigious journal Nature, attracted a lot of attention in the world of medical genetics. It was not however, universally welcomed – far from it. Another international group of medical scientists and ethicists has stated that ‘Human embryo editing against disease is unsafe and unproven …’ and even go as far as to suggest that the technology is ‘… going to be taken up by people who are pushing a eugenics agenda …’ (7). It is therefore abundantly clear that the moral and ethical questions relating to editing the genomes of human embryos remain very pertinent. Harder still and harder I have no doubt that amongst different readers of this blog there will be a range of opinions about the topics discussed so far. For anyone who is Christian (or indeed an adherent of almost any religious faith), one of the difficulties is that modern science, technology and medicine have thrown up ethical questions that could not have even been dreamed of by the writers of the Bible (or of other religious texts). We just have to use our wisdom, knowledge and general moral compass (and for some, prayer) to try to reach a decision. And if what I have already written makes that difficult, some recent developments multiply that difficulty still more. In the early years of this century, scientists developed methods of transforming a range of human cells into ‘pluripotent’ stem cells, i.e., cells capable of growing into a wide range of cell types. Further, it also became possible to get both induced stem cells and natural stem cells to actually develop into functional differentiated cells corresponding to specific body tissues. This obviously has huge potential for repairing damaged organs. However, other applications are potentially much more controversial. In 2023, Cambridge scientists reported that they had used stem cells to create synthetic mouse embryos which progressed at least as far as brain and heart formation within the normal pattern of mouse embryo development (8). However, similar synthetic embryos, implanted into mouse uteruses, did not develop to full-term.  Mouse embryos, natural at the top, synthetic at the bottom, showing similar development of brain and heart. Credit: Gianluca Amadei and Charlotte Handford.  Professor Magdalena Zernicka-Goetz, leader of the embryo development research team at Cambridge University. Credit: Simon Zernicki-Glover. At about the same time, the Cambridge group used individual human embryonic stem cells (from the blastocyst stage of embryonic development), to ‘grow’ early human embryos in the lab (9). There is no intention to use these embryos to start a pregnancy – indeed, it would be illegal to do so – but instead to study a period of embryo development which is not permitted with ‘real’ human embryos (research must not continue past 14 days of development). But how should we regard synthetic embryos? What is their moral status? For those who hold a conservative view of the normal human embryo (see earlier), should we regard these synthetic embryos as persons? Neither does the law help us. The legal frameworks covering in vitro fertilisation and early embryos (HFE Acts, 1990, 2008) do not cover artificial embryos – they were unknown at the times the legislation was drawn up. Indeed, synthetic embryos / ‘embryo models’ are, in law, not actually embryos, however much they look like/behave like early embryos. Earlier this month, the Human Fertilisation and Embryology Authority (HFEA) discussed these developments with a view to recommending new legislation but this will not dispel an unease felt by some people, including the science correspondent of one English national newspaper, The Daily Telegraph, who wrote that this research is irresponsible. But there is more. In addition to synthetic embryos, the HFEA also discussed at its recent meeting the possible use of gametes – eggs and sperm – grown from somatic stem cells (e.g., from skin) in the lab (10). Some authors have suggested that the production of gametes in vitro is the ‘Holy Grail’ of fertility research. I am not so sure about that but it is clear that a lot of effort is going into this research. Success so far is limited to the birth of several baby mice, ‘conceived’ via lab-grown eggs and normal sperm. Nevertheless, it is predicted that lab-grown human eggs and sperm will be available within a decade. Indeed, several clinicians have suggested that these ‘IVGs’ (in vitro gametes) seem destined to become “a routine part of clinical practice”. The lab-grown gametes would be used in otherwise normal IVF procedures, the only novelty being the ‘history’ of the eggs and/or sperm. Clinicians have suggested that this could help couples in which one or both were unable to produce the relevant gamete, but who still wanted to have children. In this application, the use of IVGs poses no new ethical questions although we may be concerned about the possibility of the gametes carrying new genetic mutations. However, some of the more wide-ranging scenarios do at the least make us to stop and think. For example, it would be possible for a same-sex couple to have a child with both of them being a genetic parent (obviously for males, this would also involve a surrogate mother). More extremely, a person could have a child of which he or she was actually, in strictly genetic terms, both the ‘father’ and the ‘mother’. What are we to make of this? Where are our limits? Feel free to add a comment at the end of this article. Postscript I had already decided to devote this month’s blog post to embryos, genes and related topics when my attention was drawn to an article in the January 31st issue of Church Times, ‘A theology of embryos needed’ (11). The article is written by Dr Christopher Wild, a former director of the WHO’s International Agency for Research on Cancer (and he is also a member of Christians in Science). In the article, the author discusses several of the topics that I have presented here but does so from a much more theological perspective. I thoroughly recommend it: it is clear, well-written, helpful and thought-provoking. John Bryant Topsham, Devon, UK February 2025 (1) Australian scientists produce kangaroo embryos using IVF for first time | Mammals | The Guardian.
(2) Rewinding human mistakes’: can IVF save the world’s most threatened species? | Endangered species | The Guardian. (3) Although many practitioners are now switching to call it ‘pre-implantation genetic testing’ (PGT). (4) Reviewed in Biological Sciences Review September 2019, pp 20-22 and Emerging Topics in Life Sciences (2019) 3: 687–693. Click here. (5) Heritable polygenic editing: the next frontier in genomic medicine? | Nature (6) See discussion paper from the Hastings Centre: Do We Have a Moral Obligation to Genetically Enhance our Children? | The Hastings Centre. (7) Human embryo editing against disease is unsafe and unproven — despite rosy predictions | Nature; Will genome editing transform our children's health? Some have doubts | New Scientist. (8) ‘Synthetic’ embryo with brain and beating heart grown from stem cells by Cambridge scientists | Cambridge University. (9) Synthetic human embryos created in groundbreaking advance | Biology | The Guardian. (10) Technology for lab-grown eggs or sperm on brink of viability, UK fertility watchdog finds | Reproduction | The Guardian. (11) A theology of embryology needed | Church Times. Graham (and ChatGPT) write ...  Source: forbes.com.  Alan Turing by Elliot Fry (1951). Copyright: National Portrait Gallery AI (Artificial Intelligence) has been in the news quite a bit recently, mostly it seems because of the perceived threat it poses to human existence. It can certainly be argued that AI, like any powerful technology, has the potential to be both beneficial and dangerous, depending on how it is developed and used. However, setting these issues aside, I thought it would be interesting to ‘interact’ with one of the many AI applications that are currently available to get a feel for how convincing it is at emulating human responses. British mathematician and computer scientist Alan Turing proposed a test in the 1950s to assess a machine's ability to exhibit intelligent behaviour indistinguishable from that of a human. The ‘Turing Test’ has also been the focus of relatively recent cinematic offerings such as ‘The Imitation Game’ (2014) and Ex Machina (2015). It was first introduced (‘Computing Machinery and Intelligence’, Mind, Vol. 49, pp. 433-460, 1950) as a way of considering the question ‘Can machines think?’. The setup for the classic Turing Test is pretty straight-forward, involving three participants, a human interrogator, a human respondent and a machine respondent. All interactions occur via text ensuring that physical appearance or voice do not influence the inquisitor. The objective is for the interrogator to determine which respondent is the human and which is the machine. The machine passes the test if the interrogator cannot reliably distinguish it from the human, based on its responses. It’s fair to say that, while the Turing Test is ‘iconic’, it is nevertheless a subjective judgement that is made by the interrogator. Another issue is that the test doesn’t really assess the machine’s ability to understand or reason – Turing’s original goal – but rather evaluates how well a machine mimics human communication. Bearing in mind these limitations, I initiated a conversation with one of the online AI applications – ChatGPT – which can be accessed without cost at https://chatgpt.com.  The set up of a classic Turing Test. Source: Infineon Technologies AG. Obviously, this post doesn’t represent a classic Turing Test as there is no human respondent but it’s interesting to see how well the AI apps’ output emulates human-like responses. As mentioned above, this judgement is entirely subjective - some of you may be impressed, others not so much. I opened the ‘conversation’ with the following question … Graham said: If God is loving and omnipotent, why is there so much suffering in the world? ChatGPT said: The problem of suffering is one of the most profound and difficult questions in philosophy, theology, and human experience. It has been the subject of debate for centuries and is often framed as ‘the problem of evil’. Here’s an overview of how different perspectives—religious, philosophical, and humanistic — address this question: 1. The Free Will Defence Key Idea: Human suffering is often the result of human free will.
Key Idea: Suffering is necessary for moral and spiritual growth.
Key Idea: Humans cannot fully understand God's purposes.
Key Idea: Suffering arises from living in a world governed by natural laws.
Key Idea: Suffering is the result of sin and separation from God.
Key Idea: Suffering is a natural part of existence in an indifferent universe.
Key Idea: God participates in human suffering.
Final Reflection: No single answer fully resolves the problem of suffering, and it remains a deeply personal and existential question. Different perspectives offer various ways to find meaning, hope, and action in the face of suffering. Many people draw on a combination of philosophical reasoning, religious faith, and human compassion to navigate this complex reality. How do you personally approach or reconcile this issue? Graham said: I believe that human free will is responsible for most of the suffering in the world ... ChatGPT said: That’s a thoughtful perspective. Believing that free will is the root of most suffering highlights the importance of human responsibility and moral choices. From this viewpoint, much of the world’s pain could be alleviated by better decisions—individually and collectively. How do you think free will interacts with situations beyond human control, like natural disasters or diseases? Do you see those as part of a broader context, or are they separate from moral responsibility?  Source: timescale.com Graham said: Earthquakes are actually necessary to support human life on planet Earth - recycling carbon etc. Some diseases such as cancer go hand in hand with the process of evolution. Evolution allows for the diversity of life. I have no answer for many other diseases, which seem to produce helpless suffering. ChatGPT said: You’ve highlighted a nuanced understanding of how natural processes like earthquakes and evolution play essential roles in sustaining life and fostering biodiversity, even when they result in suffering. It’s a perspective that acknowledges the complexity of life on Earth—where the very mechanisms that support life can also cause pain. The challenge of diseases that seem to cause helpless suffering is indeed difficult. Some might argue that they reflect the randomness of existence, while others see them as part of a mystery yet to be understood. Do you think science and human intervention could eventually reduce or eliminate such suffering, or do you view it as an unavoidable part of life? Graham said: Perhaps 'pointless suffering' might have been a better phase, rather than 'helpless suffering' ... ChatGPT said: That distinction makes sense. "Pointless suffering" emphasizes the difficulty of finding meaning or purpose in certain experiences, which can be even more troubling than feeling helpless. It raises profound questions about why such suffering exists if it doesn't seem to contribute to growth, survival, or a larger purpose. Do you think it's possible for meaning to emerge from what initially appears as pointless suffering, or does it remain inherently without purpose? Graham said: I guess if you believe in a God, pointless suffering may help in building resilience and character? ChatGPT said: Yes, many religious and philosophical perspectives suggest that even pointless suffering can contribute to building resilience, character, or spiritual depth. While it may not have an obvious purpose, it can still shape a person’s inner life in meaningful ways. Here are a few ways this idea is framed:  Suffering through natural disasters (source: sciencenordic.com) versus suffering through man-made events (Gaza 2024, source: Reuters). 1. Resilience and Strength
Philosophical Tension Even with these ideas, the tension remains: Why would a loving, all-powerful God allow suffering that seems excessive, random, or pointless? For many, this question is unresolved and leads to a balance between faith, doubt, and human action to reduce suffering where possible. Does this perspective resonate with you, or do you find certain aspects of it challenging? The ‘conversation’ was terminated at this point, but it could have gone on for quite a while. ChatGPT seemed to want to have the last word …  Source: Corporate Finance Institute. If you got this far in the ‘conversation’, then well done! So what do you think? I was quite impressed with the AI’s responses, and I believe that the interaction helped me to understand the question of God and human suffering, and its implications, a little more clearly. Obviously, there is no simple answer, and is definitely a matter of opinion – which is why the conversation could have gone on for some time, eventually ending up going round in big circles! Also, if there had been a human respondent, I don’t think I could have reliably identified who was who from the syntax (sentences and phrases), so I guess the AI passed the Turing Test in this respect. However, I have a feeling that I might have identified the AI from the semantics (concerned with meaning) simply because it did so well in the extent and logical structure of its responses. I think a human respondent would have been more hesitant, and somewhat less logical in framing their ideas. So, at the end of the day you could say that ChatGPT failed the Turing Test because it did too well in addressing the issue. I have to say that I didn’t see that one coming.
This brief experience of an AI application has demonstrated their power and utility and how they can be used in many applications. I hope to resist the temptation of allowing ChatGPT to write future blogs … as I have partially done with this one! May I take this opportunity to wish our readers a good 2025. Also please take the opportunity to leave a like, a greeting or a comment on this and future posts, so that we know you are there. Graham Swinerd Southampton, UK January 2025 Graham writes … As December 2024 draws to a close, it’s clear that I’m not going to be able to post a blog for this month. Many apologies for that. It’s been a manic time, and not just related to Christmas festivities. I hope to be posting something on what AI ‘thinks’ about God and suffering in early January, so I hope you will come back for that. In the meantime, as the Christmas season draws to a close, I’d like to post one of my favourite pieces of ‘popular’ music, which I hope will bless you as we move from 2024 into the new year – ‘Mary, did you know …?’ performed by Pentatonix. Their performance is spine tingling, as they bring clarity to the stunning words. If you follow our blog posts throughout the new year, please leave a greeting or a comment so that we know you are there. Wishing all our readers a happy new year! Graham Swinerd Southampton, UK December 2024  Picture credit: National Oceanic and Atmospheric Administration (USA). John writes … Well, COP 29 has finished. Did it achieve anything? Here are two reactions to the conference. The first is a brief commentary, written by me for our church on-line newsletter, while the conference was still in progress: Who is my neighbour?  Picture credit: Source unknown. I was reading a passage in Chapter 2 of Habakuk and was stopped in my tracks by the beginning of verse 8: 'Because you have plundered many nations …'. It is set in a passage about injustice, exploitation and institutional theft but my mind immediately turned to climate change (1). Climate change has been caused by the emissions of carbon dioxide from burning fossil fuels, mostly in the richer industrialised nations in support of lifestyle, industry, commerce, and warfare. However, the majority of the countries most affected are amongst the poorer nations of the world (although I acknowledge the effects of recent extreme weather events in Europe and the USA). As I have written elsewhere (2), if we factor in a country’s ability to deal with climate change along with the severity of the effects, nine of the ten worst-off countries are in Africa. This may not be direct ‘plunder’ but it certainly says something about inequality and global justice. It is no surprise that at COP 29, there have been demands from poorer countries for financial help to deal with climate change – something which I believe we should support in whatever way is possible for us.  The second is a Podcast, made by Chatham House (an independent international affairs think tank), towards the end of the conference while negotiations were still in full swing – to listen to podcast, click on this link: https://www.chathamhouse.org/.../independent-thinking-has...  My final comment, now that the conference has finished, is four-fold.
First, the amount agreed for payment to poorer countries is somewhat of a compromise Secondly, despite pressure from oil-rich nations, it is clear that we are making progress towards renewable energy sources and away from fossil fuels. Thirdly however, that progress is not fast enough. We are still heading for a temperature increase of at least 2 degrees, with possibly disastrous effects on tipping points. Fourthly, if you are a praying person, please pray about this John Bryant Topsham, Devon November 2024 (1) I was pleased to see that a recent commentator on this passage, Revd. Amanda Bloor, reacted in a similar way. (2) Introduction to Bioethics, 2nd Edition, Wiley, 2019. John writes ...  Sunrise in the forest. Credit: photowall.com 'The earth is the Lord’s, and everything in it … for he founded it on the seas' (from Psalm 24). King David equated creation with ownership and went on to consider God’s awesome majesty, holiness and even ‘otherness’. Certainly, when we think about the universe in all its magnificence, awe is one of the emotions that we also feel. But look now at the previous psalm, the very well-known 23rd, in which David thinks of God as knowing him personally, nurturing, caring, providing for his needs – a very different picture from that of awesome majesty but equally valid. In our own reaction to God’s creation, many of us have experienced similar emotions, holding in tension the awesomeness of the creator with the understanding that he cares about us and indeed about the whole of creation. And so I end with this gentle exhortation entitled ‘On Holy Ground’ written by Peter Millar and published by the Iona Community*. Go gently my friends: feel the good earth beneath your feet, celebrate the rising of the sun, listen to the birds at dawn, walk gently under the silent stars, knowing you are on holy ground held in love – in the wonder of God’s creation.  Under the stars. Credit: Joshua Earle. John Bryant Topsham, Devon October 2024 *50 New Prayers from the Iona Community, ed. Neil Paynter, Wild Goose Publications, 2012. Graham writes ...  Jupiter seen from the surface of Europa. Credit: Getty Images and Ron Miller.  Despite fears that the Europa Clipper (EC) spacecraft might not survive the radiation environment at Europa, the spacecraft launched on schedule. A SpaceX Falcon heavy lift launch vehicle left the famed 39A launch pad (the historic Apollo 11 mission left from here in July 1969) at 12.06 EDT (16.06 GMT) on the 14th of October 2024, just 4 days after the launch window opened on 10 October. However, now we all need to be patient – if all goes well, EC will enter Jupiter orbit in April 2030. Nevertheless, this is a great opportunity to look forward to what it is hoped EC will achieve, at an overall mission cost of around US$5-billion. Back in May of this year, the launch looked to be in jeopardy (for details see previous ‘miniblog’ – click on ‘August 2024’ on the RHS of this page) when a problem was discovered concerning the reliability of electronic components already installed in the integrated spacecraft. An issue was suspected with the transistor elements, which are essentially the building blocks of the micro-processors onboard. The Jupiter system, where EC will operate, exposes the spacecraft to intense particle radiation similar to the Earth’s Van Allen radiation belts but 50 times more intense. To survive this the electronic systems need to be housed in a protective radiation vault engineered with 9 mm thick walls composed of aluminium and titanium. In addition, the electronic components are required to be ‘radiation-hardened’ to achieve the spacecraft’s planned 3.5 year mission lifetime. Earlier this year, it was found that identical transistors failed under testing before they should. This posed a real problem for the engineers. Would they have to replace the installed transistors, or would they have to redesign the flight profile to achieve the mission objectives in a shorter time scale? Both of these are major undertakings – either of which would have threatened the readiness of the spacecraft to launch within the bounds of the upcoming launch window.  Integration, assembly and test of Europa Clipper in the clean room environment. Credit: NASA Following this potentially devastating news, NASA instigated four months of 24-hour intensive testing at three different facilities – JPL in Pasadena, California, the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland and the NASA Goddard Space Flight Centre in Greenbelt, Maryland. After evaluating spare components from the same batches that were installed on EC, the test engineers found that the spacecraft’s systems would, afterall, perform as required. This conclusion partially rested on the fact that during the first half of its mission lifetime, the spacecraft will be in the most intense of Jupiter’s radiation only one out of every 21 days.  Schematic of the spacecraft's radiation environment. Credit: source unknown. To get an idea how this works, the diagram above shows a ‘plan view’ of the Jovian system with Jupiter at the centre and the orbits of the major (Galilean) moons shown in black. A representative elliptical EC orbit is shown in blue and the radiation hazard is shown roughly by the red, gold and beige areas, red being the most intense. As can be seen, in order to execute flybys of Europa the spacecraft must dip into the red zone, but there is a mitigating factor. Due to the nature of elliptical orbits, the spacecraft’s speed at the perijove (point of closest approach to Jupiter) is very much higher, than its speed at apojove (point of furthest distance), so EC will spend most of its time outside of the damaging radiation environment. Hence for the majority of the time, the orbiter will remain outside the region of greatest hazard. Also, during this time the components can be partially restored from radiation damage by gently heating them (a process called ‘annealing’).  The crazed, icy surface of Europa as seen by the Galileo spacecraft. Credit: NASA. So why is Europa, a body about the size of Earth’s moon, the subject of such intense interest? As I said in my previous blog post, it has long been thought to be a place in the Solar System where conditions may be suitable for life to develop. Looking at Europa – a distant and cold, ice-covered world – it doesn’t look at all like an environment where life could flourish. However, in this case, appearances are deceptive. There is strong evidence that beneath the ice crust there is a warm water ocean, the heat being generated most likely by volcanic vents on Europa’s ocean bed. It is currently believed that the depth of this ocean is up to 100 km, so that Europa may have twice the volume of water compared to terrestrial oceans! So, how does this vulcanism work? The key to understanding lies with the massive gravitational pull Jupiter exerts on its moons. As Europa orbits the gas giant, tidal forces cause the icy moon’s interior to flex which generates thermal energy within the moon’s rocky core, increasing the likelihood of volcanoes on the ocean bed. Other Galilean moons, Io in particular, exhibit intense volcanic activity on their surfaces driven by the same mechanism.  Depiction of a water plume on Europa. Credit: Corey S. Powell. Suspicions that there may be an ocean beneath Europa’s icy surface were first raised by imagery acquired by NASA’s Galileo spacecraft which orbited Jupiter from 1995 to 2003. A good example is the image below of Europa’s icy surface taken at a range of about 200 km during a flyby in November 1997. In this region, the surface ice appears to have melted, broken up and then refrozen, suggesting surface thawing caused by heating from below. Furthermore, recent reanalysis of old Galileo mission data suggests that the Galileo spacecraft may have flown through plumes of water vapor emanating from the moon during flybys.  A closeup image of Europa's surface, acquired by the Galileo spacecraft. Credit: NASA/JPL. So, what do we hope to learn from the EC mission? Clearly, there is no way that it can perform an in-situ investigation of potential life signatures at the ocean bed. The objectives must be limited by what can be achieved remotely during the planned 50 flybys of Europa, at ranges as low as 25 km. The over-riding motivation for the mission is to do a detailed study of the Europa system to investigate whether the icy moon could harbour conditions suitable for life to exist. To work out the orbital profile of the mission and to determine what payload instruments are required, the mission objectives (in general terms) may be expressed as:
Based upon these broad objectives the engineers were able to determine the characteristics of the spacecraft. In other words, they can decide on the payload instruments needed to achieve the objectives, and what services are required on board to support these instruments. The ‘services’ are usually referred to as subsystems such as electrical power, communications, data handling, attitude control (required to point the instruments as appropriate), propulsion, structure, and so on.  Europa Clipper reflected in the solar array, during a solar array deployment test. Credit: NASA and Frank Michaux. This process led to the design that we see in the final integrated spacecraft, which is now on its way to Europa. With a dry mass of more than 3.2 tonnes, a height of roughly 5 metres, and a width of more than 30 metres with its solar panels fully unfurled, EC is the largest spacecraft that NASA has ever built for a planetary mission. To handle the large transmission rate of payload data over such large distances, the spacecraft is equipped with a 3 metre diameter communications dish. All previous NASA deep-space missions have been much more compact due to the use of radioisotope thermal generators (RTGs) to provide electrical power. These devices use the heat from radioactively decaying elements to produce electricity. The use of solar arrays in this instance is a significant change in design philosophy for NASA. Given that Jupiter is 5 times further from the Sun than Earth, the amount of power per unit area is 25 times less (the ‘inverse square law’!). This means that the incident solar power at Jupiter is only about 55 W per square metre, so lots of array surface area is needed to supply the spacecraft’s electrical needs resulting in the spacecraft’s large size, as seen below.  The size of Europa Clipper compared to a basketball court. Along the array axis the spacecraft is in excess of 30 m. Credit: NASA/JHUAPL. A major payload component is an ice-penetrating radar to determine the structure of Europa’s icy crust and to attempt to acquire direct evidence of sub-surface water. The spacecraft's is also equipped with two sets of cameras, one operating in the visible part of the spectrum and the other in the infra-red (thermal imaging) to produce a high resolution map the moon’s surface and look for potential plumes. The thermal sensor will help pinpoint locations of warmer ice and perhaps recent eruptions of water. EC also carries spectrometers, again operating in different parts of the spectrum to determine the composition of the surface and atmosphere. Spectrometers measure the intensity of reflected light from Europa across a band of frequencies (or colours, if the instrument is operating in the visible part of the spectrum). Particular surface elements or compounds will absorb light at particular frequencies (colours) leaving dark lines in the surface spectrum, revealing their presence. In addition, a magnetometer will measure the moon’s magnetic field, and perturbations to the vehicle’s trajectory during close flybys will provide information about its gravity field, both of which will offer clues about Europa’s internal structure.  Depiction of an Europa Clipper flyby of Europa. Credit: NASA. Stepping back and looking out into the Solar System in general, there is a growing trend with current and proposed missions to give the search for life a high priority. When I was growing up and learning about our planetary system this was not the case. In those times, it was firmly believed that Earth was the only seat of life in the Solar System, and the remainder of the planets were considered to be sterile wastelands (both hot and cold). This was entirely understandable given that at that time everything we knew about our planetary system was acquired remotely through terrestrial telescopes. However, with the advent of the space age, an armada of spacecraft has ventured out into the Solar System, visiting each of the major planets. The recent emphasis on the search for life is epitomised by our current investigations of Mars. It is now recognised that in its early history Mars was a water world, and that life may have developed there. Current rovers are equipped with instruments to detect possible bacterial life that may still dwell in the rock beneath their wheels. However, Mars is not the ideal laboratory to undertake this investigation. It is not often acknowledged that Mars is not quarantined from Earth, so that any life found there may have originated here (or indeed vice versa). To understand how this is possible, we have to go back maybe 3 or 4 billion years when life was thought to be stirring on our world. Alongside this, the early Solar System was a very hazardous place with lots of debris left over from its formation. Large impact events on Earth occurred often, throwing rocks off the planet and into solar orbit. It is possible that ‘earthling bacteria’ could have hitched a ride on this ejecta, to ultimately arrive on the Martian surface. Interestingly, the recent discovery of underground reservoirs of water on Mars (see August 2024 blog – click on the date on the RHS of this page) may reshape the way we think about Martian life.  Europa's mysterious interior. Credit: Nature. This is why I find missions like Europa Clipper so exciting. If we find life there, it is very likely that it has nothing at all to do with life on planet Earth. The postulated Europan ocean is isolated by a crust of ice which is thought to be somewhere between 3 and 30 km thick. Though no sunlight can penetrate that shell to power life, there is a good theoretical basis to believe that vents that release heat from the moon's interior exist on its ocean floor. Indeed, similar vents in Earth’s deep oceans teem with life. There is a school of thought that advocates these terrestrial vents could have been where life originated on our planet. If, ultimately, we do find life on Europa we have no idea what form it will take. Will it be based upon a DNA-type organisation, but with a different code? Will we even recognise it as life at all? The discovery of non-terrestrial life is a whole new ball game that we have yet to play!
In passing, it is worth mentioning that there is another prime suspect in our Solar System where life may reside. A moon of Saturn called Enceladus is a body which exhibits a lot of similarities with Europa. Here NASA’s Cassini Saturn orbiter mission (2004-2017) identified water plumes emanating from an ice crust, below which is believed to lie an ocean warmed by tidal vulcanism. However, this is another story! Now that I have acquired the grand old age of 74, I’m not sure that I will be around to see the outcome of this mission! However, I do hope so – it could very well be a profound milestone in our understanding of whether extra-terrestrial life is extremely rare (and precious) or very abundant throughout the Universe. Graham Swinerd Southampton, UK October 2024 John writes ...  Some personal history. One sunny morning in May 2011 I went to the local teaching hospital to receive a diagnosis based on a biopsy that had been taken a few days earlier. The result was very clear: the pigmented patch on the shin of my left leg was, as suspected by me and by the dermatology consultant, a melanoma, which is the most aggressive type of skin cancer (1). It was a very early-stage melanoma and was unlikely to have spread. The nurse-practitioner who conveyed the news indicated that the melanoma would be removed by surgery followed by a skin-graft. I had that treatment a few weeks later and having chosen to receive only local anaesthetic, was able to watch with interest the whole procedure. I would also have regular checks for a year to see whether or not the cancer had spread – which fortunately it never did.  Main entrance of the Royal Devon and Exeter Hospital. Credit: Royal Devon University Healthcare NHS Foundation Trust. During the conversation about the diagnosis and projected treatment, the nurse-practitioner also explained that, at the time, there were no effective chemotherapies for melanoma (although some had been tried) and so, if the cancer had spread, surgery would again be the treatment. However, during the 15-minute drive home, I listened to a radio programme that presented recent advances in medical science. The first item that came up was the approval by the NHS of an immuno-therapy for treating advanced melanoma. In other words, the treatment involved stimulation of the body’s immune system to specifically target the melanoma cells. There followed testimonies from patients whose advanced melanomas had been treated very successfully by the new therapy. Indeed, one woman said that secondary tumours in her liver had been destroyed so quickly that for a while, the liver had holes and gaps in it, as the body’s regeneration mechanisms could not keep up with the rate of destruction of cancer cells. As I listened to this during my brief car journey my mood was significantly elevated. I realised that, if by chance the medics are wrong and my melanoma does spread, there is now a treatment for it. The immuno-therapy was widely taken up by doctors treating metastatic melanoma (i.e. melanoma which had spread to other parts of the body) and among its recipients was former USA president, Jimmy Carter who was treated very successfully at the age of 90!  Former USA President Jimmy Carter at the age of 90. Credit: LBJ Library. The treatment spreads. The announcement of an effective immuno-therapy for melanoma immediately led to the idea that similar therapies could be introduced for other cancers. It would require the identification for each cancer of a specific antigen for that cancer, for example, a protein on the surface of the cancer cells. The patient’s immune system would then be stimulated to raise antibodies to target the cancer cells, as had been done for melanoma. Immuno-therapeutic treatments have now been developed for a wide range of different cancers or cancer sub-types whilst at the same time, several different versions of the original treatment have been developed, depending on which protein(s) is/are targeted (2). More recently, immuno-therapy has been combined with genome editing and genetic modification in two slightly different ways in order to cure very difficult cases of childhood leukaemia (3).  Alyssa, cured of her aggressive leukaemia by an immuno-therapy that also involved genome editing and genetic modification techniques. Credit: Great Ormond Street Hospital. Back to the 1960s. In targeting antigens, whether in a cancer cell or a pathogen, we are targeting proteins, albeit that some of them may be modified, for example by the addition of carbohydrate groups to make glycoproteins. It is therefore helpful to remind ourselves of a couple of features of the synthesis of proteins. The structure of proteins is encoded in DNA with, for the most part, one protein being encoded in one gene. But the genes are separated from the sites in the cell where the proteins are made, so how does the code in a gene direct the synthesis of a protein. Several scientists, including Sydney Brenner at Cambridge, predicted that genes were copied into ‘messenger’ molecules that took the code to the sites of protein synthesis. Two international teams (French/British/American) assembled especially for the job, and working in two different labs in the USA, confirmed that this hypothesis was correct. The messenger molecules are made of RNA and are hence known as messenger RNA. In bacteria, the messenger RNA (mRNA) molecules are relatively short-lived, as described in the papers published by the two teams (4) but in other organisms, the longevity of mRNA molecules varies between genes.  Sydney Brenner, FRS, Nobel Laureate (1927 – 2019) in 2002, the year in which he was awarded the Nobel Prize. Credit: www.youtube.com. Working with messages. It goes without saying that we have come a very long way since those early discoveries. We now have means of identifying the mRNA copied from a specific gene amongst the thousands of mRNAs copied from other genes. This enables us to ascertain when a gene is actively being copied so that we can look at the patterns/timings of expression of particular genes in relation, for example, to particular life events. Thus, in my field, it has been possible to study the expression of different genes by measuring the amount of their particular mRNAs in relation to the phases of the cell division cycle (5). Further, it is now possible to make mRNA molecules corresponding to specific genes. This is not without its difficulties – single-stranded RNA molecules such mRNA are susceptible to breakdown when existing outside the cellular environment. This is true both of those messages which are longer-lived in the cell and those which are shorter-lived. However, methods of improving very significantly mRNA stability have been developed – an advance which has opened up a huge range of possibilities. Bringing everything together. Earlier in this article, we saw that many cancers can now be treated by immuno-therapy, inducing the body to make antibodies to particular cancer proteins (antigens), often by injecting the patient with the purified protein. But what if we asked a patient’s body to actually make an ongoing supply of the antigen to achieve a higher level of antibody production? How would we do this? I am sure that many of our readers have already reached the correct answer to that question but in order to complete my story, I am going to return to the COVID pandemic. The key feature which I want to emphasis is that several of the most successful vaccines did not involve injection of an antigen (the spike protein) but the mRNA encoding the antigen – so our own cells made the spike protein and our immune system made antibodies against it. Brilliant! The success of the Covid vaccines almost immediately led to questions in the cancer research community – if it works for vaccination surely mRNA technology could also work for immuno-treatment of cancer. And the question has now been answered, as revealed in an announcement in February this year that clinical trials involving mRNA-driven cancer immune-therapy had been initiated at Hammersmith Hospital, London (6). This announcement was followed just last month by the news that a lung cancer patient at University College London Hospitals (UCLH) had been started on immuno-therapy based on mRNA (7). Cancer does indeed ‘get the message’.  Messenger RNA-based immuno-therapy may be delivered by simple injections. Credit: BBC News. Incidentally, both the announcement from UCLH and the BBC’s coverage of this development talked of a ‘novel cancer vaccine’, based on the similarity of the technique to that used in Covid vaccines. However, as I have emphasised elsewhere (8), this is not actually a vaccine (it is not used to try to prevent cancer) but a treatment for use when someone actually has cancer.
Concluding comments I have told a story here that entwines the applications of research from three different areas of biological/biomedical science, namely cancer cell biology (including cell division), immunology and molecular biology. As a long-term member of the molecular biology community (including work with mRNA) I am delighted that the discoveries made by scientists are being applied for human benefit. As a Christian I believe that science is a gift from God – curiosity about how the world works is embedded in the human species and some of us are privileged to exercise that curiosity in our work. Equally, I believe that it is important to use our knowledge wisely and where possible in fulfilling the commandment ‘Love your neighbour’ in practical ways, exemplified by the work described here. John Bryant Topsham, Devon September 2024 (1) The consultant also told me that long-distance runners were probably at greater risk of getting skin cancer on the legs than the general population. (2) Immunotherapy for Cancer – NCI. (3) ‘Introduction to Bioethics’(2nd Edition), Bryant and la Velle, Wiley/Blackwell (2019), p. 139; Cancer therapy involving genome editing cures another child’s leukaemia – Genomics Education Programme (hee.nhs.uk), Meet Alyssa | Great Ormond Street Hospital Charity (gosh.org). (4) Discovery of messenger RNA in 1961 (Pasteur.fr). (5) For example, Genes encoding two essential DNA replication activation proteins, Cdc6 and Mcm3, exhibit very different patterns of expression in the tobacco BY-2 cell cycle – PubMed (nih.gov). (6) First UK patients receive experimental mRNA therapy for cancer | NIHR. (7) First UK patient receives innovative lung cancer vaccine: University College London Hospitals NHS Foundation Trust (uclh.nhs.uk). (8) Link to author's interview on Youtube: www.youtube.com. |
AuthorsJohn Bryant and Graham Swinerd comment on biology, physics and faith. Archives
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