Month: September 2022

CLOCKS AND BURSTS. "The findings that in many if not most lineages evolution is dominated by gene (and more generally, DNA) loss that occurs in a roughly clock-like manner whereas gene gain occurs in bursts associated with the emergence of major new groups of organisms imply a biphasic model of evolution." http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

TWO PHASES. "The first, innovative phase of evolution is temporally brief, engenders dramatic genomic and phenotypic perturbations, and is linked to population bottlenecks. The second, reductive phase that represents “evolution as usual” is protracted in time, is facilitated by the deletion bias that seems to be a general feature of genome evolution." http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

INCREASING COMPLEXITY. "The biphasic model of evolution...is not all-encompassing as continuous, long-term increase in genome complexity (but not necessarily biological information density) is observed in various lineages, our own history (that is, evolution of vertebrates) being an excellent case in point."" " https://lnkd.in/egqWFZp http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

NEW VIEW. "Contrary to widespread and perhaps intuitively plausible opinion, genome reduction is a dominant mode of evolution that is more common than genome complexification, at least with respect to the time allotted to these two evolutionary regimes." http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

REDUCTIVE MODE. "Many if not most major evolving lineages appear to spend much more time in the reductive mode than in the complexification mode. The two regimes seem to differ also qualitatively in that genome reduction seems to occur more or less gradually, in a roughly clock-like manner, whereas genome complexification appears to occur in bursts accompanying evolutionary transitions." http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

SO ENDS this contemplation of the surprising fact that increasing genome complexity occurs in short burst, fueled in part by introns, followed by longer periods of streamlining and simplification during evolution. Mobile introns are known to shape the diversity of their host genes, and are transferred horizontally, being of viral origin. Viruses have played a major role in genetic innovation during the evolution of practically every species on earth. Is this co-evolution or directed progress? https://lnkd.in/dUmr2-J View in LinkedIn

SELECTION FOR AGING? "Much about aging in the biosphere points to the inference that aging has been positively selected. Nevertheless, evolutionary biologists have resisted this interpretation because it is theoretically implausible." http://joshmitteldorf.scienceblog.com/2013/07/22/evolution-of-evolution-and-evolution-of-death/ View in LinkedIn

UNIT OF SELECTION. "Aging is bad for the individual fitness, and the individual counts for more than the community when it comes to natural selection." http://joshmitteldorf.scienceblog.com/2013/07/22/evolution-of-evolution-and-evolution-of-death/ View in LinkedIn

ANONYMOUS NICHE. "The only benefit of aging is that it leads to death that creates a vacancy in the niche. This vacancy could be filled by a close relative or a distant relative or no relative at all, an animal that doesn’t age or even an animal of a different species that shares some of the same food species. Kin selection and even MLS models are not promising for evolution of aging." http://joshmitteldorf.scienceblog.com/2013/07/22/evolution-of-evolution-and-evolution-of-death/ View in LinkedIn

EXTRA SPACE. "Until the 20th century, many biologists thought that natural selection favoured old age because it made space for the next generation. If too many people lingered, the group as a whole would suffer. But there was a problem with this logic: the longer individuals live, the more offspring they generally leave. Death might create more room, but it won’t help a species survive." https://lnkd.in/dgftu7G View in LinkedIn