New Insights on the Evolutionary Relationships Between the Major Lineages of Amoebozoa

Abstract

The supergroup Amoebozoa unites a wide diversity of amoeboid organisms and encompasses enigmatic lineages recalcitrant to modern phylogenetics. Deep divergences, taxonomic placement of some key taxa and character evolution in the group largely remain poorly elucidated or controversial. We surveyed available Amoebozoa genomes and transcriptomes to mine conserved putative single copy genes, which were used to enrich gene sampling and generate the largest supermatrix (824 genes) in the group to date. We recovered a well-resolved and supported tree of Amoebozoa, revealing novel deep level relationships and resolving placement of enigmatic lineages congruent with morphological data. In our analysis the deepest branching group is Tubulinea. A recent proposed major clade Tevosa, uniting Evosea and Tubulinea, is not supported. Based on the new phylogenetic tree, paleoecological and paleontological data as well as data on the biology of presently living amoebozoans, we hypothesize that the evolution of Amoebozoa probably was driven with the need to disrupt and graze on microbial mats - a dominant ecosystem of the mid-Proterozoic period of the Earth history.