What'sNEW
...biosignatures contained within freshly deposited ice in high-latitude regions on the surface of Europa are detectable using laser-induced UV fluorescence, even from an orbiting spacecraft.
 "Fluorescent Biomolecules Detectable in Near-Surface Ice on Europa," by Gideon Yoffe et al, arXiv:2503.06971 [astro-ph.EP], 11 Mar 2025.
 Life on Europa, Other Moons, Other Planets? has related updates.
James Lovelock, the founder of the Gaia theory, had a long and interesting life. Near the end of it, he granted journalist Jonathan Watts complete access to his correspondence and records, household and family, and many hours of interviews. Now the definitive biography of Lovelock is published. It includes an unusually close look at his personal life, and some facts that surprise even those who knew him best. Having read little about Lovelock except what he himself wrote, I was surprised to learn about his long association with Shell Oil and his extensive classified work for British military intelligence. I was also glad to know about Dian Hitchcock, whom he met at JPL, and who helped shape the first iteration of Gaia. Years afterward, Lovelock even influenced Magaret Thatcher to become a powerful advocate for the environment. Watts, also an environmental activist, is annoyed that Lovelock didn't do even more, but ultimately he portrays him as a multi-talented, complex, imperfect, lovable hero. Very highly recommended.
At JPL and NASA, Lovelock and Hitchcock guessed that life-detection could be done by looking at the atmosphere. Oxygen and methane are both found on Earth, but this situation cannot persist without something that keeps supplying them. It must be life, they concluded — the planet is breathing. Meanwhile, Mars's atmosphere is in chemical equilibrium. From a top-down perspective, Lovelock and Hitchcock concluded that Mars is dead. (I think it may be only comatose, with a poor prognosis.)
Later in the development of Gaia, Lynn Margulis enters the picture. A biologist, she knew that methanogens make methane and cyanobacteria make oxygen. Lovelock then taught us about many other environmental effects of microbial metabolism, such as the burial of carbon in marine limestone. Cosmic ancestry depends on these bottom-up planetary engineering aspects of Gaia. On Earth, they have succeeded far better than anywhere else we can observe. But do they explain the redness of Mars, or the methane lakes of Titan, for example? And what would Lovelock, an early expert on dimethyl sufide, have to say about its appearance on comets, asteroids and extrasolar planets?
The Many Lives of James Lovelock: Science, Secrets and Gaia Theory, by James Watt, Canongate Books, 2024.
 Thanks for a review copy, Jackie Flanagan.
Gaia has comments and links about planetary engineering and the environment.
How is it Possible? has early speculations about panspermia and planetary engineering.
Bacteria: The Space Colonists suggests that they could start anywhere.
Life on Mars! has support for "comatose".
| 26 Apr 2025 |
What'sNEW about HGT
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...'mitochondrial transfer' has been observed in a wide variety of cells and in organisms as diverse as yeast, molluscs and rodents. What?! Mitochondria can escape from eukaryotic cells and move to other cells within the organism? ...by three different mechanisms? The phenomenon is not in doubt, and probably has implications for human health. But as another kind of gene transfer, could it also, somehow, have implications for evolution?
Cells are swapping their mitochondria...., by Gemma Conroy, Nature, 10 Apr 2025.
Viruses and Other Gene Transfer Mechanisms has all our links about HGT.
The only scenario that currently explains all the data ...is one where K2-18b is a hycean world teeming with life, says Nikku Madhusudhan, astrophysicist at the Institute of Astronomy, University of Cambridge, UK. The exoplanet, seen with the James Webb Telescope, is 124 lightyears away and 8.6 times as massive as Earth, orbiting in the "habitable zone" of a red dwarf star. It appears to have a global ocean and a hydrogen-rich atmosphere that also contains dimethyl sulfide (DMS) and dimethyl disulfide (DMDS). On Earth, these trace gasses come only from microbial life such as marine phytoplankton.
"Scientists find strongest evidence yet of life on an alien planet," by Will Dunham, Reuters, 16 Apr 2025; re:
"New Constraints on DMS and DMDS in the Atmosphere of K2-18b from JWST MIRI," by Nikku Madhusudhan et al, doi:10.3847/2041-8213/adc1c8, ApJL, 17 Apr 2025.
Thanks, Jim Powers and Rob Cooper.
02 Jul 2024: More about extraterrestrial DMS.
12 Sep 2023: An earlier report from the same UK team.
Life on Europa, Other Moons, Other Planets? links to more examples.
"A Possible Biosignature at K2-18b?," informed commentary by Paul Gilster, Centauri Dreams, 18 Apr 2025.
...we present here complete, phased, diploid genomes of six ape species.... A large international team of genomicists, bioinformaticians and others, captained by Evan Eichler, has resolved many of the former difficulties in sequencing the genomes of humans and their near relatives. Now they have made those genomes available to all. One important benefit is ...the added value for standard evolutionary analyses.... For example, the figure below shows human chromosome 16 compared to the corresponding chromosomes (descending in the figure) in chimpanzee, bonobo, gorilla, Bornean orangutan and Sumatran orangutan. The green ribbons indicate "a single transposition [that] relocates about 4.8 Mb of gene-rich sequence in gorilla."
Excellent. Here is extensive precise sequencing for relatively recent evolution. The sequences include hundreds of new candidate genes and regions to account for phenotypic differences among the apes. The transitions include insertions, relocations and inversions of large segments. Given the approximately known populations and time brackets, it shoud be possible, under neo-darwinian logic, to calculate the likelihood of the human evolution revealed here, particularly that of the "new candidate genes."
"Complete sequencing of ape genomes," by Yoo, D., Rhie, A., Hebbar, P. et al. (>100 authors), doi:10.1038/s41586-025-08816-3, Nature, 09 Apr 2025.
"What makes us human? Milestone ape genomes promise clues," by Humberto Basilio, Nature, 09 Apr 2025.
04 Jan 2016: Thousands of human and/or chimpanzee-specific genes are derived from previously silent DNA.
30 Sep 2005: The chimp genome has been sequenced.
Human Genome Search describes an early, related project, begun Nov 2001.
New genetic programs... describes a naive continuation of the project.
Robust Software Management: a system for managing insertions, relocations, inversions, etc.
Thanks, Evan Eichler, 13 Apr 2025.
Observations of interstellar extinction probably provide the most direct clues concerning the optical properties of interstellar dust. So wrote Chandra Wickramasinghe, in 1972, in a 500-page oversize reference book on the subject. Interstellar dust was a little-noticed topic, but, by then Wickramasinghe had spent ten years investigating it with Fred Hoyle. The book includes some history and many equations, but the bulk of it is columnar tables listing values of scattering functions and graphs of extinction curves for particles of different shapes and compositions. Wickramasinghe had become a world authority. No one had looked more carefully.
Light-Scattering Functions for Small Particles, by N.C. Wickramasinghe, Adam Hilger, London, 1973.
Chandra Wickramasinghe has an early essay about evolution, and many updates.
In 1972, the sizes and shapes of the dust particles were still imperfectly known, and the composition might include graphite and water ice. As the research continued, more evidence for larger, life-related organics emerged, the size range of the particles narrowed, and clues about their refractance began to converge. After almost 20 years, in 1981, Fred Hoyle and Wickramasinghe reached an astounding conclusion — freeze-dried bacteria provided the best match, by far, for the dust. Initially, they were as surprised as anyone. A chronicle of this research, from 1962 to 1983 is available in a collection of 25 scientific papers and accompanying discussion. The story needs to be much better known; this record makes it hard to dismiss.
From Grains to Bacteria, by Fred Hoyle and Chandra Wickramasinghe, University College Cardiff Press, 1984.
Hoyle and Wickramasinghe's Analysis of Interstellar Dust has background.
Fred Hoyle Interviewed... includes his account of their finding bacteria in space.
| 03 Apr 2025 |
What'sNEW about HGT
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...the diatom Nitzschia sing1 ...abandoned its original photosynthetic lifestyle, ...to thrive on algae derived sugars...[by acquiring] an alginate lyase gene from a marine bacterium. Once integrated into the diatom's genome, the ancestral alginate lyase underwent extensive duplication and diversification.... [A] significant functional shift in the ...enzymes was driven by a 15-base pair insertion, which restructured the enzymes' catalytic pockets to favor terminal cleavage rather than internal cutting.
According to cosmic ancestry, macroevolutionary advances become possible when genetic programming is acquired. The acquired sequence can be tested for ultimate deployment, silent retention, or rejection. Testing could include duplications, targeted insertions, deletions and recombinations. It might might even include "directed" point mutations for task optimization. Another example of HGT seems to neatly illustrate much of this testing and deployment.
"A single enzyme becomes a Swiss Army knife," by Andreas Sichert, PLoS Biol, 02 Apr 2025; re:
"Diatom heterotrophy on brown algal polysaccharides emerged through horizontal gene transfer, gene duplication, and neofunctionalization," by Zeng Hao Lim et al, doi:10.1371/journal.pbio.3003038, PLoS Biol., 01 Apr 2025; and:
"...How a borrowed bacterial gene allows some marine diatoms to live on a seaweed diet," Phys.Org, 01 Apr 2025.
Robust Software Management is a proposed name for the operating system that tests acquired programming.
Viruses and Other Gene Transfer Mechanisms cites >1,000 examples of HGT into eukaryotes.
According to neo-darwinism (including all modern variants), mutation-and-selection are sufficient to write new genetic programs leading to macroevolutionary advances. Where are the clear illustrations of that process?
Testing Darwinism versus Cosmic Ancestry elaborates on this question.
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