List I | List II | ||
---|---|---|---|
A | Robert May | I | Species-Area relationship |
B | Alexander von Humboldt | II | Long term ecosystem experiment using out door plots |
C | Paul Ehrlich | III | Global species diversity at about 7 million |
D | David Tilman | IV | Rivet popper hypothesis |
Evolution is a process that occurs in changes in the genetic content of a population over time. Evolutionary change is generally classified into two: microevolution and macroevolution. The process of changes in allele frequencies in a population over time is a microevolutionary process. Three main mechanisms that cause allele frequency change are natural selection, genetic drift, and gene flow. On the other hand, macroevolution refers to change at or above the level of the species.