CAS BI 107 Lecture Notes - Lecture 14: Cambrian Explosion, Anatomical Terms Of Location, Evolutionary Developmental Biology
8 Oct 2015
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Document Summary
Genetic toolkit: conserved genes that code for transcription factors. Evolutionary changes in these toolkit genes result in major differences. Ex) number of legs in arthropods due to changes in a gene from the genetic toolkit. 540 mya cambrian explosion: ancestors of every living species today arose. From this period, the genetic toolkit was created. Act similarly across divergent taxa, indicating that there is a common ancestor between bilaterians. Determines axial patterning of the embryo during early development of all bilateral metazoans. Shared developmental mechanisms controlled by specific dna sequences comprise a genetic toolkit that has been modified and reshuffled to produce the remarkable diversity of plants, animals, and other organisms we know today. Small changes in the application of the genetic toolkit when, where, and how much the transcription factor genes are expressed influence the development of the organism and produce variation upon which natural selection can work.
