Month: September 2022

VERTICAL INHERITANCE. “Meaningful transfer of genetic information occurs—and only occurs—in a linear pattern from parent to progeny. This, again, is an assumption that only applies to multi-cellular eukaryotes.” https://standardsingenomics.biomedcentral.com/articles/10.1186/s40793-016-0180-8 View in LinkedIn

VERTICAL WORLD. “Thus, all of the lineage-based species concepts applied to multi-cellular eukaryotes satisfy all of the biodiversity constraints noted above, viz., they are all completely anchored in the idea of shared evolutionary history and fate and they all, in consequence, deliver species groups whose members exhibit great similarity of phenotype and ecological role.” https://standardsingenomics.biomedcentral.com/articles/10.1186/s40793-016-0180-8 View in LinkedIn

HORIZONTAL WORLD. “However, none of the species concepts as applied to prokaryotes satisfy any of those conditions. Paraphrasing Hey, the problems involve both the theoretical understanding of how prokaryotes exist in nature and the operational methods for identifying prokaryotic species.” https://standardsingenomics.biomedcentral.com/articles/10.1186/s40793-016-0180-8 View in LinkedIn

DISRUPTIVE CONCEPT. “The occurrence of large-scale horizontal gene transfer certainly has the potential to disrupt the notion of lineages, shared evolutionary fate, or shared evolutionary history, three of the key constraints on species concepts useful for biodiversity studies.” https://standardsingenomics.biomedcentral.com/articles/10.1186/s40793-016-0180-8 View in LinkedIn

VERTICAL VERUS HORIZONTAL WORLDS. “From both a mechanical and a theoretical perspective, the way genetic material is transmitted through organisms over time is fundamentally different in prokaryotes. This leads prokaryotic biologists to use the word “species” in a manner that is decidedly at variance with the concept as applied to multi-cellular eukaryotes.” https://lnkd.in/ewnQ9Vg View in LinkedIn

NO SPECIES BARRIER. “They conclude that inter-specific genetic exchange was a major evolutionary driver and that one species ( S. mitis ) provided the bulk of genetic variation for another species ( S. pneumoniae ). This is not an atypical finding. In prokaryotes, the bulk of new gene families arise via inter-species horizontal gene transfer, not intra-species gene duplication.” https://lnkd.in/ewnQ9Vg View in LinkedIn

NOT ABOUT REPRODUCTION. Genes in the prokaryotic world have little to do with reproduction. They are shared liberally by horizontal gene transfers across species. In the eukaryotic world they are exclusively related to reproduction through vertical mendelian inheritance. https://lnkd.in/ewnQ9Vg View in LinkedIn

SOURCE OF GRIST. Horizontal gene transfer has been providing the bulk of prokaryotic genetic novelty over time. https://standardsingenomics.biomedcentral.com/articles/10.1186/s40793-016-0180-8 View in LinkedIn

NEW SPECIES THINKING. “The upshot is that the multi-cellular eukaryote “species-as-lineage”—or any phylogeny-based species concept—cannot be applied to prokaryotes because they lack discrete, whole-genome lineages.” https://standardsingenomics.biomedcentral.com/articles/10.1186/s40793-016-0180-8 View in LinkedIn

NEW INDIVIDUAL THINKING. “Similarly, neither can the multi-cellular eukaryotes notion of an “individual” be applied straightforwardly to prokaryotes. Efforts to squeeze prokaryotes into these multi-cellular eukaryotes notions will produce results that are either metaphorical or misleading or wrong.” https://standardsingenomics.biomedcentral.com/articles/10.1186/s40793-016-0180-8 View in LinkedIn