SO ENDS this first of two weekends on the startling consequences of promiscuous horizontal gene transfer in microorganisms, creating the planet’s largest gene pool. These tiny creatures, so long overlooked, are the Atlases that drive immense biogeochemical cycles of matter. Professor Doolittle ingeniously suggests that their tiny metabolisms cog with these great cycles of matter as functional units of natural selection, rather than their rather meaningless species designations. https://lnkd.in/dk3R9p6y View in LinkedIn
BLUNT FORCE. “But it is arguably the case that abandoning any requirement for holobionts to be units of selection and/or to reproduce collectively, is, for all intents and purposes, throwing out the baby with the bathwater.” https://lnkd.in/dk3R9p6y View in LinkedIn
MICROBE-MACROBE. “O’Malley (forthcoming) envisions that the emphasis on collective community function will fade as more individual microbe–macrobe interactions come under mechanistic scrutiny; we suspect she is right.” https://lnkd.in/dk3R9p6y View in LinkedIn
RESISTANCE. “Perhaps unsurprisingly, there has been pushback from more conservative philosophers and microbiologists over what would justify claims that holobionts ought rightly to be called units of selection.” https://lnkd.in/dk3R9p6y View in LinkedIn
ANALOGY. “Hologenomic evolution is most easily understood by equating a gene in the nuclear genome to a microbe in the microbiome... Evolution for both genes and symbionts is fundamentally a change in population frequency over successive generations, i.e., the fraction of holobionts carrying that particular nuclear allele or microbe.” (Bordenstein and Theis). https://lnkd.in/dk3R9p6y View in LinkedIn
MIGHTY MICROBES. “We have known for many decades that major biogeochemical cycles in the ocean or on land are driven by microbes and that microbes affect animal, human, and plant health directly in many ways, not all negative.” https://lnkd.in/dk3R9p6y View in LinkedIn
UNITS OF SELECTION. “Here, we argue that interaction patterns as entities do in fact vary, pass on traits to later instances of themselves, and differ in propensity to spread and persist; they thus act as units of selection.” https://lnkd.in/dk3R9p6y View in LinkedIn
THE REFRAIN. “Put metaphorically, what matters is the song, not the singer. The song, to flesh out this metaphor, is the pattern of interactions (metabolic, structural, or developmental) between partner lineages (the singers).” https://lnkd.in/dk3R9p6y View in LinkedIn
FUNCTIONAL EVOLUTION. “So, if the idea that microbial consortia are units of selection is to be borne out, it might be better to focus on evolutionary processes at a functional level, not the taxonomic level of partner organisms and their lineages.” https://lnkd.in/dk3R9p6y View in LinkedIn