Hypotheses of Fungi Evolution:
One hypothesis proposes that aquatic fungi evolved from ancestral flagellates (choanoflagellates) that we still find in extant protist species. The problem is in explaining that fungi are osmotrophs like bacteria and yet were flagellate like other eukaryotes before becoming terrestrial. The only remaining aquatic fungi are the Chytrids that still have flagellated spores, so are considered the most basal group extant. This indicates fungi branched before phagocytosis evolved and after sexual reproduction with motile gametes.
Eukaryotes clearly went in three trophic niches
Auto-phototrophs – algae and plants
Osmo-heterotrophs – absorbing heterotrophs – mycetozoa and fungi
Phago-heterotrophs – engulphing or ingesting heterotrophs – protozoa and animals
Microbial Phylogeny and Evolutionhttp://books.google.com/books?id=SMvLpiK…http://books.google.com/books?id=ANT8VB1…http://faculty.college-prep.org/~bernie/…http://www.sciencedaily.com/releases/200…
Choanoflagellates relate to metazoan choanocyte collar cells in sponges, and the origins of animal multicellularity and possibly fungal also.http://onlinelibrary.wiley.com/doi/10.11…http://www.wisegeek.com/what-are-choanof…http://www.tolweb.org/Choanoflagellateshttp://books.google.com/books?id=-GyARby…