BIOL 202 Study Guide - Final Guide: Ordovician, Diencephalon, Nephron
Document Summary
Biology 202: diversity of life ii final review. Pikaia graciilens seems tobe the earliest found vertebrate. Some have argued that vertebrates are the product of survival of the luckiest as all of the animals at the time were well adapted to their environments and had similar proportions in the community. Vertebrates: probably originated by paedomorphosis ( sexual maturation of the larval form) of a urochordate like ancestor. Underwent a duplication of the hox genes, which control development. This was key in the development of vertebrates as it allowed them to form more complex and varied structures. The 3 body aces are now defiend: the blastopore will form the anus, the mouth will form at the opposite end . The animal pole will form the back and the vegetal pole will form the abdomen. Cells still lack differentiation but their fates have been determined: neurulation: dorsal mesoderm cells aggregate into a rod-like structure.
