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THE VIRUS FACTORY. “On one side, the bacteria are metabolically active, stealing ATP and biochemical precursors from their hosts to transcribe their genomes, translate their proteins, replicate their DNA, and divide. On the other side, one sees a large but metabolically silent viral particle, not deserving to be described as living by most biologists. This traditional view might, however, be a case of 'when the finger points to the stars, the fool looks at the finger'. Rather than comparing a parasitic cell to the virus particle, I believe we should compare it to the 'virus factory'.” https://lnkd.in/eyzfrxe View in LinkedIn

SEX WARS. "Rival sex genes may be at war with each other, causing intersexual development, or at least infertility. For instance, what will be the sex of a hybrid that has both a male-determining Y and a female-determining W?" https://lnkd.in/ehjz378 View in LinkedIn

RNA TO DNA. “Also quite provocative is the idea that RNA viruses might be at the origin of DNA biochemistry. According to this scenario, RNA-based viruses infecting RNA-based cells would have acquired an RNA-to-DNA modification system to resist cellular RNA-degrading enzymes (the RNA equivalent of present-day bacterial restriction and modification systems).” https://lnkd.in/eyzfrxe View in LinkedIn

INFECTIOUS NUCLEUS. “Of particular interest, such a transfer of an 'infectious' nucleus is well documented in many parasitic red algae. Such back-and-forth eukaryogenesis-viriogenesis could readily explain the multiplicity of present-day virus lineages, together with their diversity in size, complexity and gene complement, as well as the apparent mixture of monophyly and polyphyly (descent from more than one ancestor) exhibited by the viral world.” https://lnkd.in/eyzfrxe View in LinkedIn

NUCLEAR VIROGENESIS. “I personally find the general idea that a nucleus is functionally equivalent to a selfish DNA virus (that is, replicating 'its' DNA using the cellular metabolism) simple and very appealing - and even more so when one realizes that the idea can be turned on its head to envisage the nucleus of a (primitive) eukaryote (re-)turning into a large DNA virus - the notion of nuclear viriogenesis.” https://lnkd.in/eyzfrxe View in LinkedIn

DIVERSE REPRODUCTION. “Viruses are also more diverse when it comes to reproduction. "Cells only have two main ways of replicating their DNA," said Patrick Forterre, a virologist at Paris-Sud University. "One is found in bacteria, the other in Archaea and eukaryotes." Viruses, on the other hand, have many more methods at their disposal.” https://lnkd.in/eXmJ-Tt View in LinkedIn

ONGOING Y CHROMOSOME EVOLUTION. "Will it be replaced by some different gene and chromosome? And if so, will this unleash a new round of hominid speciation? We may have to wait another 4.6 million years to find out." https://lnkd.in/ehjz378 View in LinkedIn

HUMAN CONSEQUENCE? "What does this mean for our own lineage? The primate Y seems to be more stable than the rodent Y. But if it continues to degrade at the same rate, it will disappear in about 4.6 million years." https://lnkd.in/ehjz378 View in LinkedIn

SO ENDS the first weekend on the topic of the impact of viruses on the evolution of life. Still considered by many biologists to be just rough pieces of genetic material not worthy of inclusion in the tree of life, there are some who propose a very central role for viruses in the evolution of life. This seems to be a case of not seeing the wood for the trees, bogged down in details, or our mesmerized fixation on the pointing finger, rather than on what it points at. View in LinkedIn

PERMANENT HITCHHIKERS. “After they have entered a cell, viruses become part of the genetic information of the host cell, and all of its progeny are forever changed.” https://lnkd.in/guhpmyR View in LinkedIn