Lec31_handout - BioG1780 Evolution and Biodiversity...

BioG1780 Fall 2010
Evolution and Biodiversity Today’s lecturer: Harry Greene
Lectures 31: November 12, 2010
1. Animals—Out of the soup: body plans and the hole that matters. With this and remaining
biodiversity lectures we explore the remarkable adaptive radiation of animals, as well as certain other
closely related and fascinating eukaryotes. In terms this lecture, first review pp. 583-585 in Ch. 27 of
Sadava et al. regarding basal lineages of Unikonts, then read Ch. 31 on the rise of animals.
2. What are Unikonts, Opisthoconts, and Animals? As is the case for Plantae, the lineages basal to
fungi and animals are relatively simple and retain shared primitive features (NB: what is the technical
general term for such attributes?) with more basal eukaryotes. Uniconts have a single flagellum and
consist of opithoconts (fungi, choanoflagellates, and animals) and amoebozoans (the loboseans or
amoebae and the slime molds). Relatively basal fungi (like chytrids), choanoflagellates, sponges, and
amoebozoans are all unicellular or relatively simple multicellular organisms, and thus also like most
other relatively basal eukaryotes. Indeed, we can now look back at the basic eukaryote TOL and
observed repeated, independent “descent with modification” resulting in increasing complexity (e.g., in