BIOLOGY 1B Lecture 4: Bio 1B Prelab 4
Document Summary
Emcompasses events such as formation of higher taxa (genera, fam, orders, etc. ) Adaptive radiations: appearance of new organisms in unexploited habitats. Cladistics, evidence for environmental and biological change. Something happens to make clade undergo lots of speciation all at once. Definition = period of relatively rapid speciation that coincides with evolution of beneficial phenotype, a new char that has higher fitness than the living organisms. Either outcompete and to fill their niches (ecological roles), or find new niches that no other able to utilize. Cladogram = branching diagram, illustrates evolutionary relationships between species. Difference with phylogeny is that phylogeny has relationships scaled relative to time. Dramatic evolution with crown height of teeth (hypsodonty) Think it"s bc of environment, but recent data shows inconsistencies with this hypothesis. Going to test hypothesis that change in vegetation (evolution of grasslands) Know timing of changes in morphology and taxonomic diversity. Mammalian teeth has 2 parts: crown and roots.
