horizontal gene transfer

David Quammen, author of The Tangled Tree:A Radical New History of Life, a biography of Darwin skeptic Carl Woese, who discovered the Archaea, offers a long reflection at the New York Times on how biology is moving away from Darwinism: Woese was a rebel researcher, obscure but ingenious, crotchety, driven. He had his Warholian 15 minutes of fame on the front page of The Times, and then disappeared back into his lab in Urbana, scarcely touched by popular limelight throughout the remaining 35 years of his career. But he is the most important biologist of the 20th century that you’ve never heard of. He asked profound questions that few other scientists had asked. He created a method — clumsy and Read More ›

Researchers Iranzo and Koonin ask: Typically, natural selection results in deletions of harmful genes, so the main question is, why hasn’t natural selection wiped out genetic parasites? They mean “transposons, plasmids, viruses” etc., that offer no benefit to the hosts. They offer a hypothesis: In a new study published in EPL, researchers Jaime Iranzo and Eugene V. Koonin at the National Institutes of Health in Bethesda, Maryland, have found that horizontal gene transfer may be one of the keys to understanding the persistence and spread of genetic parasites over evolutionary timescales. In horizontal gene transfer (HGT), genetic information is transferred to an organism by a variety of mechanisms other than the traditional parent-to-offspring process of transferring DNA. For example, an Read More ›

Including things you didn’t know about Archaea discoverer, Carl Woese. From a review of The Tangled Tree:A Radical New History of Life by David Quammen (Simon & Schuster, 2018): In The Tangled Tree, celebrated science writer David Quammen tells perhaps the grandest tale in biology: how scientists used gene sequencing to elucidate the evolutionary relationships between living beings. Charles Darwin called it the ‘great Tree of Life’. But as Quammen reveals, at the molecular level, life’s history is more accurately depicted as a network, a tangled web through which organisms have been exchanging genes for more than 3 billion years. This perspective is indeed radical, and he presents the science — and the scientists involved — with patience, candour and Read More ›

The genes were transferred to the beetles, researchers say, from sea squirts (tunicates) , with whom they have, may we say, not much in common, by microorganisms (symbiont bacterial strains). From ScienceDaily: An international team of researchers led by scientists of Johannes Gutenberg University Mainz (JGU) and the Leibniz Institute for Natural Product Research and Infection Biology in Jena has discovered that bacteria associated to Lagria villosa beetles can produce an antifungal substance very similar to one found in tunicates living in the marine environment. The researchers revealed that this commonality is likely explained by the transfer of genes between unrelated microorganisms. … The discovery of a new bioactive substance produced by the dominant strain B. gladioli Lv-StB was particularly Read More ›

Which now seem to serve an as-yet-unknown function in the bat. From ScienceDaily: Some 18 million years ago, an ancestor of mouse-eared bats “stole” genetic material from an ancient virus related to Bola. The swiped genetic sequence — a gene called VP35 — has remained largely intact in the bats despite the passage of time, with few changes since it was co-opted, a new study finds. The research also sheds light on the gene’s possible function in bats, suggesting that it may play a role in regulating the immune system’s response to threats. “We’re using a multidisciplinary approach to understand the evolution, structure and function of a viral gene co-opted by a mammal,” says Derek J. Taylor, PhD, an evolutionary biologist at Read More ›

From ScienceDaily: Far from just being the product of our parents, University of Adelaide scientists have shown that widespread transfer of genes between species has radically changed the genomes of today’s mammals, and been an important driver of evolution. In the world’s largest study of so-called “jumping genes,” the researchers have traced two particular jumping genes across 759 species of plants, animals and fungi. These jumping genes are actually small pieces of DNA that can copy themselves throughout a genome and are known as transposable elements. They have found that cross-species transfers, even between plants and animals, have occurred frequently throughout evolution. Both of the transposable elements they traced — L1 and BovB — entered mammals as foreign DNA. This Read More ›

From ScienceDaily: A new study by scientists at the University of Liverpool documents, for the first time, how the ability of bacteria to swap genetic material with each other can directly affect the emergence and spread of globally important infectious diseases. Known as ‘horizontal gene transfer’, this phenomenon is understood to have played a role in developing the global antimicrobial resistance (AMR) crisis. However, the dynamics of AMR transfer through bacterial populations and its direct impact on human disease is poorly understood. It’s poorly understood, in part, because Darwinism is enjoined on the public instead of a proper appreciation of the many dimensions of evolution. Plasmids are small circular DNA molecules that can be transferred horizontally between bacteria. They contain Read More ›

Not how we are all apes but how bacteria can get the better of us? Jathink? From ScienceDaily: That may sound scarce; however, .” ..as only a small number of strains (<10%) were isolated from farm and urban environments, we were surprised to find one with mcr-1 on a transferable plasmid, which is a relatively high frequency of detection compared to the clinical strains,” the researchers wrote. (Plasmids are independent, mobile genetic elements that can be transmitted from one bacterium to another — sometimes across species, bestowing the traits they carry upon a new bacterial host — in this case, resistance to the last resort drug, colistin.) “Isolation of plasmid-mediated colistin resistance in S. flexneri from animal feces on a Read More ›

From ScienceDaily: “It’s exciting and significant to find a living family of giant viruses with eukaryote-specific genes in a form that predates the latest common ancestor of all eukaryotes,” says Albert Erives, associate professor in the Department of Biology. “These viruses are like time machines that tell us more about how life on our planet came to be.” In the study, Erives analyzed the genome of a virus family called Marseilleviridae and found it shares a similar set of genes, called core histones, with eukaryotes. That places Marseilleviridae, and perhaps its viral relatives, somewhere along eukaryotes’ evolutionary journey. “We now know that eukaryotes are more closely related to viruses,” says Erives, “and the reason is because they share core histones, Read More ›

From Rafi Letzter at LiveScience: According to two papers published in the journal Cell in January, long ago, a virus bound its genetic code to the genome of four-limbed animals. That snippet of code is still very much alive in humans’ brains today, where it does the very viral task of packaging up genetic information and sending it from nerve cells to their neighbors in little capsules that look a whole lot like viruses themselves. And these little packages of information might be critical elements of how nerves communicate and reorganize over time — tasks thought to be necessary for higher-order thinking, the researchers said. Though it may sound surprising that bits of human genetic code come from viruses, it’s Read More ›

From ScienceDaily: Bacteria not only develop resistance to antibiotics, they also can pick it up from their rivals. In a recent publication in Cell Reports, Researchers from the Biozentrum of the University of Basel have demonstrated that some bacteria inject a toxic cocktail into their competitors causing cell lysis and death. Then, by integrating the released genetic material, which may also carry drug resistance genes, the predator cell can acquire antibiotic resistance. … The predator bacteria take up the released DNA fragments. If these fragments carry certain drug resistance genes, the specific resistance can be conferred upon the new owner. As a result, the antibiotic is no longer effective and the bacterium can reproduce largely undisturbed. Pathogens with such abilities Read More ›

Horizontal gene transfer on skates. Wow, re evolution. From ScienceDaily: A new study finds that viruses share some genes exclusively with cells that are not their hosts. The study, reported in the journal Frontiers in Microbiology, adds to the evidence that viruses swap genes with a variety of cellular organisms and are agents of diversity, researchers say. The study looked at protein structures in viruses and across all superkingdoms, or domains, of life: from the single-celled microbes known as bacteria and archaea, to eukaryotes, a group that includes animals, plants, fungi and all other living things. “It is typical to define viruses in relation to their hosts, but this practice restricts our understanding of virus-cell interactions,” said University of Illinois Read More ›

From Jordana Cepelewicz at Quanta: Nigel Goldenfeld applies the physics of condensed matter to understand why evolution was blazingly fast for the earliest life — and then slowed down. Cepelewicz So how can collective effects in physics inform our understanding of evolution? Goldenfeld: When you think about evolution, you typically tend to think about population genetics, the frequency of genes in a population. But if you look to the Last Universal Common Ancestor — the organism ancestral to all others, which we can trace through phylogenetics [the study of evolutionary relationships] — that’s not the beginning of life. There was definitely simpler life before that — life that didn’t even have genes, when there were no species. So we know Read More ›

But leaves phylogeny unclear. From ScienceDaily: Tardigrades are microscopic animals, justly famous for their amazing ability to withstand complete dehydration, resurrecting years later when water is again available. Once desiccated, they have been frozen in ice, exposed to radiation, sent into space vacuum… and still they spring back to life. Tardigrades became more famous recently when it was suggested that their DNA was a mix of animal and bacterial segments, making them “Frankenstein” hybrids. The new research has now laid the Frankenstein idea to rest by arguing that tardigrade DNA looks “normal,” with no evidence that these special animals use extraordinary means to survive. Previous ideas that they might have taken up large numbers of foreign genes from bacteria are Read More ›

Also, doubts about horizontal gene transfer persist. First, from Suzan Mazur earlier at Huffington Post on deep evolution: I recently had a three-way phone conversation with Swedish deep evolution investigators Charles Kurland and Ajith Harish about their phylogenomic Tree of Life (ToL) based on protein structure, which shows that we are descended from a “complex” ancestor — MRUCA (most recent universal common ancestor) — not a simple bacteria. Kurland and Harish think a ToL paradigm shift may be in order. What’s more, Kurland and Harish figure that MRUCA was not the first ancestor, but represents complex survivors of a now-extinct biosphere. Now, just recently from Mazur, again at Huffington Post, a report on the pushback: There has been a vigorous and somewhat Read More ›