Too Much Eukaryote LGT

Abstract

The realization that prokaryotes naturally and frequently disperse genes across steep taxonomic boundaries via lateral gene transfer (LGT) gave wings to the idea that eukaryotes might do the same. Eukaryotes do acquire genes from mitochondria and plastids and they do transfer genes during the process of secondary endosymbiosis, the spread of plastids via eukaryotic algal endosymbionts. From those observations it, however, does not follow that eukaryotes transfer genes either in the same ways as prokaryotes do, or to a quantitatively similar degree. An important illustration of the difference is that eukaryotes do not exhibit pangenomes, though prokaryotes do. Eukaryotes reveal no detectable cumulative effects of LGT, though prokaryotes do. A critical analysis suggests that something is deeply amiss with eukaryote LGT theories.

Analyzing Horizontal Transfer of Transposable Elements on a Large Scale: Challenges and Prospects

“…Horizontal transfer (HT) of genetic material is the transmission of DNA between organisms that are not necessarily closely related, through mechanisms other than reproduction . While the frequency, impact, and mechanisms underlying these transfers are well understood in prokaryotes, HT in eukaryotes is less studied and remains relatively obscure . One type of HT among eukaryotes is widespread though, that of transposable elements (TEs).…”

Symbiogenesis, gradualism, and mitochondrial energy in eukaryote origin

“…In brief, most claims for eukaryote LGT are probably untrue (74). Here it is only important to stress that there are gradualist and symbiogenetic views on LGT as it specifically relates to eukaryote origin.…”

“…The gradualist view is that eukaryotes started out their evolutionary history as obligate aerobes, that the ancestral mitochondrion was an obligate aerobe specialist like Rickettsia (68), and that the ability to survive in anaerobic environments was gradually acquired during evolution in various eukaryotic lineages via lateral gene transfer (LGT), either from prokaryotes or from eukaryotes that had themselves become anaerobic via earlier gradual LGTs (69,70,71,72,73). There are several major problems with the origin of eukaryotic anaerobes via LGT, as discussed at length elsewhere (74), in addition to minor problems, such as the fact that the gradualist LGT origin for eukaryote anaerobes hinges wholly upon Lamarckian inheritance (traits being impressed from the environment into eukaryotic inheritance).…”

“…The role of lateral gene transfer in eukaryote evolution has been more thoroughly addressed elsewhere (74). In brief, most claims for eukaryote LGT are probably untrue (74).…”

“…Should we teach our students that eukaryotes, including animals (146), evolve in a Lamarckian manner? There is something fundamentally wrong with eukaryote LGT claims (74).…”