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SIGMOID CURVE. "In fact, all cells can do is divide, produce products of differentiation, migrate or remain in place, and die, but the combination of these activities over the course of time are described by a curve. Remarkably, for the years between puberty and senescence, this curve for human beings parallels the Gompertzian exponential." https://muse.jhu.edu/chapter/275818 View in LinkedIn

EUKARYOTE LOSSES. "Even more striking conclusions were reached by the reconstruction of the evolution of the eukaryotic protein domain repertoire that involved comparison of 114 genomes. The results of this reconstruction indicate that most of the major eukaryotic lineages have experienced a net loss of domains that have been traced to the LECA." (LECA = last eukaryotic common ancestor). http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

NORMATIVE LITTLE DEATHS. "One can now list the number of times particular tissues are replaced in one year: lining of the small intestine; lining of the stomach; epidermal covering of the lips; hepatocytes of the liver; lining of the trachea; and lining of the bladder. And all this replacement is perfectly normal and not a consequence of trauma. Ultimately, biologists recognized the role of cells in death as well as life: a living thing dies when its cells no longer develop or maintain it." https://lnkd.in/dTkk9-R View in LinkedIn

WIDESPREAD LOSS. "Even animals and plants, the eukaryotic kingdoms that seem to be the least prone to gene loss, have lost about 20% of the putative ancestral genes identified in the unicellular Naegleria. Collectively, these findings imply that the genome of the LECA was at least as complex as the genomes of typical extant free-living unicellular eukaryotes." (LECA = last eukaryotic common ancestor). http://onlinelibrary.wiley.com/doi/10.1002/bies.201300037/full View in LinkedIn

PATHWAY? "Death is not the waste of life it sometimes seems, but the pathway through which energy flows through virtual life and through its fractals." (Whatever that means). https://muse.jhu.edu/chapter/275813 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

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

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

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

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