Year: 2022

ONEROUS CONCEPT. “In fact even for organisms with regular and obligatory recombination and obvious barriers to intertaxon mating, the notion of species is onerous.” https://lnkd.in/djKBnru View in LinkedIn

AUGMENTED EXPLANATION. “Rather than replacing periodic selection on genetic diversity, gene loss, and other chromosomal alterations as important players in adaptive evolution, gene exchange acts in concert with these processes to provide a rich explanatory paradigm.” https://lnkd.in/djKBnru View in LinkedIn

RARE COMBINATION EVENTS? “Bacterial population geneticists have known for some time that prokaryotic genomes do sometimes recombine, but early estimates suggested that rates of recombination were sufficiently low to be ignored when considering periodic selection events.” https://lnkd.in/djKBnru View in LinkedIn

NEW FINDINGS. “Expanding multilocus sequence typing (MLST) surveys now show that it is often homologous recombination—not the stepwise accumulation of mutations after separation of lineages—that accounts for the lion's share of sequence differences between isolates.” https://lnkd.in/djKBnru View in LinkedIn

BUSH NOT TREE. “A study of conserved loci in bacterial pathogens, conclude for lineages within a species that “over the long term, the impact of relatively frequent recombination is to obliterate the phylogenetic signal in gene trees such that the relationships between major lineages of many bacterial species should be depicted as a network rather than a tree.” https://lnkd.in/djKBnru View in LinkedIn

BACTERIAL GENE SWAPS. “The genomes of individuals within such a species would thus resemble each other because of frequent exchange of genes and parts of genes via a common gene pool and not (except indirectly) because they share a common ancestor.” https://lnkd.in/djKBnru View in LinkedIn

BACTERIAL RECOMBINATION EVENTS. “Because of recombination, “phylogenies of different genes from individuals of the same species should be significantly different, whereas the phylogeny of genes from individuals of different species should not be significantly different”. That is, frequent recombination should result in conflicting molecular phylogenies for genes in conspecific organisms.” https://lnkd.in/djKBnru View in LinkedIn

FRAGMENT FROM NATURE continues the meditation on nature’s connectivity from a remarkable essay by Bill Graham, a former marine biologist. As a scientist, he has not only made his own observations and gathered those of others together, but has formulated some general principles about interconnectivity. I hope that you enjoy this as much as I have. View in LinkedIn

BEGINNINGS. “One of the most important characteristics of complex systems is their sensitivity to initial conditions.” https://lnkd.in/gA5rxGc View in LinkedIn

“EMERGENCE is inextricably tied to complex systems.” https://lnkd.in/gA5rxGc View in LinkedIn