BIOS10112 Lecture Notes - Lecture 3: Convergent Evolution, Holocene Extinction, Burgess Shale
Document Summary
Living organisms have three essential properties: 1. Use energy in some type of way: 2. Replicate system by which they pass on their genes to future generations. Geological timescale huge gap between the formation of multi-celled organisms and single celled organisms. Are we in a mass extinction now the sixth mass extinction: 5 eras, chart measures extinctions per millions species year, on graph: Orange= threatened: what we take away from this not that many species have gone extinct, but if all the species that are labeled as threatened/endangered go extinct, this will be a mass extinction. Evolutionary biologists we do(cid:374)"t k(cid:374)ow how (cid:373)ost orga(cid:374)is(cid:373)s are related: these people construct the history of life try to figure out how organisms are related. Phylogeny: a hypothesis about how organisms are related like any hypothesis, a phylogeny can be strongly or weakly supported, and it might change with more evidence: made up of clades.
