BISC 102 Lecture Notes - Lecture 2: Ediacaran Biota, Sirius Passet, Burgess Shale

• School: Simon Fraser University
• Department: Biological Sciences
• Course: BISC 102
• Professor: Rolf Mathewes

Document Summary

Stromatolites: fossils as evidence of precambrian life (sedimentary rocks formed by (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) (cid:1) aquatic environments, abundant species, long lived lifespan, etc. A good example of homoplasy is the evolution of the eye which has originated independently in many different species. Your answer: arthropods, mollusks, chordates, and a variety of soft-bodied organisms. In the study of anolis lizards that colonized various caribbean islands, similar habitats and ecological types were found on hispaniola and. Your answer: different islands were initially colonized by different species that differed in habitat preference, but in both cases subsequent speciation produced a range of ecological specialists occupying similar habitat niches. The phylogeny for each island was unique, but species evolved having similar sets of adaptations for each habitat. Adaptive radiations = new exploitable environment + morphological innovations. By chance, the k-p impact caused extinction of the dinosaurs but did not greatly affect the small, nocturnal, scavenging mammals.