BIO SCI 94 Lecture Notes - Lecture 4: Proterozoic, Burgess Shale, Overfishing

• School: UC-Irvine
• Department: Biological Sciences
• Course: BIO SCI 94
• Professor: Robin Bush

Document Summary

Chapter 28 part 2 - adaptive radiation and mass extinction. Adaptive radiation - rapid evolutionary diversification within one lineage, producing many descendant species with a wide range of adaptive forms. Speciation occurred relatively rapidly compared with other groups. Morphological innovations - morphological trait makes it possible to exploit resources in new way or occupy new habitats. Photosynthesis, oxygen in atmosphere, photosynthetic eukaryotes - Cambrian explosion - tremendous incr in size and morphological complexity of animals, accompanied by diversification in how they made a living. Higher oxygen lvsl (made aerobic respiration more efficient) Evolution of predation - exertion of selective pressure for prey defensive strategies, driving morphological divergence. New niches beget more new niches - ability to exploit new niches created new niches for predators and drove divergence. New genes, new bodies - mutations, incr number of hox genes in animals, making it possible for larger, more complex bodies ot evolve.