Ecology Notes

Evolution as a theory * Theory- in science, a well substantiated explanation of some aspect of the natural world
Evolution- the accumulation of inherited genetic changes within populations over generations * Does not refer to changes that occur in an individual within its lifetime * Not limited to speciation that may only occur over long periods of time * Can occur over a few generations, and is most commonly expressed as an adaptation to a changing environment or the change in allele frequencies of genes * Adaption- a modification that improves the changes of survival and reproductive success in a given environment * Natural selection * Variation * Overproduction * Limits on population growth * Differential reproductive success * Gregor Mendel- Mendel’s principles of segregation and independent assortment
Modern synthesis * Integration between the units of evolution and the mechanism of evolution * Mutation- a permanent change in a cell’s DNA including: * Nucleotide sequences * Alteration of gene positions * Gene loss or duplication * Insertion of foreign sequences
Modern synthesis- unification and development of several branches of biology that previously had little in common particularly * Paleontology * Systematics * Developmental biology * Behavioral * Ecology
Evidence for evolution * Fossil record * Biogeography * Homoplasy * Selective breeding * Homologies * Experiment evidence of adaptation
Fossil record * Complex organisms in younger rocks * Simple organism in older rocks
Biogeography
* Study of geographical distribution of extinct and modern species * Isolated continents
Homoplasy (similar form- different origin) * Homoplastic- features are similar features not inherited from a common ancestor * May adapt in similar ways to similar environments; convergent evolution * Homoplastic