Horizontal gene transfer provides new insights into biological evolution
The discovery of horizontal gene transfer (HGT) has challenged the Darwinian “tree of life” concept and, at the same time, has provided new insights into biological evolution. HGT is not only frequent in prokaryotes and unicellular eukaryotes, but also occurs in multicellular eukaryotes. In this article, we review the occurrence and evolutionary significance of HGT in the three major groups of multicellular eukaryotes (animals, plants, and fungi). We also briefly discuss HGT detection methods and possible transfer mechanisms, and offer some predictions about the overall trend of HGT occurrence in multicellular eukaryotes.