Reticulate evolution
[1] Reticulate patterns can be found in the phylogenetic reconstructions of biodiversity lineages obtained by comparing the characteristics of organisms.
[2] Reticulate evolution can happen between lineages separated only for a short time, for example through hybrid speciation in a species complex.
Nevertheless, it also takes place over larger evolutionary distances, as exemplified by the presence of organelles of bacterial origin in eukaryotic cells.
[1] The adjective reticulate stems from the Latin words reticulatus, "having a net-like pattern" from reticulum, "little net.
It has been found to be driven by symbiosis, symbiogenesis (endosymbiosis), lateral gene transfer, hybridization and infectious heredity.
Eukaryotic organelles, such as mitochondria, have been theorized to have been originated from cell-invaded bacteria living inside another cell.
[21][22] However, most methods for studying cladistics have been based on a model of strictly branching cladogeny, without assessing the importance of reticulate evolution.
[24] Reticulate evolution refers to evolutionary processes which cannot be successfully represented using a classical phylogenetic tree model,[25] as it gives rise to rapid evolutionary change with horizontal crossings and mergings often preceding a pattern of vertical descent with modification.
[4] The urgent need for new models which take reticulate evolution into account has been stressed by many evolutionary biologists, such as Nathalie Gontier who has stated "reticulate evolution today is a vernacular concept for evolutionary change induced by mechanisms and processes of symbiosis, symbiogenesis, lateral gene transfer, hybridization, or divergence with gene flow, and infectious heredity".
[30] Wild types possessing desirable agronomic traits are selected and fused in order to yield novel, improved species.
[32] There is evidence of reticulation events in flowering plants, as the variation patterns between angiosperm families strongly suggests there has been widespread hybridisation.
[34] Genetic transfer can occur across wide taxonomic levels in microorganisms and become stably integrated into the new microbial populations,[35][36] as has been observed through protein sequencing.
[38] Lateral genetic transfer of photo-response genes between planktonic bacteria and Archaea has been evidenced in some groups, showing an associated increase in environmental adaptability in organisms inhabiting photic zones.
