BIOL 123 Lecture 1: Biol 123 - LTR 1
Document Summary
Biological evolution: is any change in the inherited traits of a population that occurs from one generation to the next. Can understand similarities and differences between species. Can understand why species are present in one area but not another. Cetaceans fishlike bodies (whales, sharks, dolphins) Possess similar features to fish but similar to mammals as well: develop in uterus, placenta, mothers milk. Darwin believed they lived on land because they possessed these features. Natural selection: is a mechanism that can lead to evolution, whereby differential survival and reproduction of individuals cause some genetic types to replace (outcompete) others. Homology: structural characters that are shared because they are inherited from a common ancestor (homologous: characteristics are similar in 2 or more species because they are inherited from a common ancestor) Synapomorphy: a derived form of a trait that is shared by a group of related species. Darwin argued evolution is a gradual process.
