BIO SCI 94 Lecture Notes - Lecture 6: Habitat Destruction, Iridium Anomaly, Cambrian Explosion

• School: UC-Irvine
• Department: Biological Sciences
• Course: BIO SCI 94
• Professor: Nancy Burley

Document Summary

Macroevolution - pattern of evolution over large time scales. To generate macro evolution is the same thing that generate micro evolution. Current estimates: 4. 54 by (meteorites, oldest planetary lead, moon rock, No o2 , much solar radiation, but heavy bombardment of bolides ended. Precambrian: the first 4 billion yrs on earth. Oxygen revolution: evolution of oxygenic photosynthesis (2. 8 bya) (cyanobacteria) 1. 5 bya - levels high enough for multicellular aerobic eukaryotes. Many phyla of living animals suddenly appear in fossil record. Colonization of land (by various groups in paleozoic era) Associated with adaptations to reproduce on land and prevent dehydration and prevent dehydration. Continental drift = motion of continents over geological time. Influences climate, sea level, builds mountain ranges, volcanism, distribution of organisms and evolution (esp. by breaks of gene flow) Mass extinction = a large scale, sudden extinction event that is geographically and taxonomically widespread. Defined by number of species (or families) lost.