Microevolution
From Free net encyclopedia
Microevolution is the occurrence of small-scale changes in allele frequencies in a population, over a few generations, also known as change at or below the species level.
These changes may be due to several processes: mutation, natural selection, gene flow, and genetic drift.
Population genetics is the branch of biology that provides the mathematical structure for the study of the process of microevolution. Ecological genetics concerns itself with observing microevolution in the wild. Typically, observable instances of evolution are examples of microevolution; for example, bacterial strains that have antibiotic resistance.
Microevolution can be contrasted with macroevolution; which is the occurrence of large-scale changes in gene frequencies, in a population, over a geological time period (i.e. consisting of lots of microevolution). The difference is largely one of approach. Microevolution is reductionist, but macroevolution is holistic. Each approach offers different insights into evolution.
Because microevolution can be observed directly, creationists agree that it occurs, though they tend to make a distinction between microevolution, macroevolution, and speciation.
| Basic topics in evolutionary biology | (edit) |
|---|---|
| Processes of evolution: evidence - macroevolution - microevolution - speciation | |
| Mechanisms: selection - genetic drift - gene flow - mutation - phenotypic plasticity | |
| Modes: anagenesis - catagenesis - cladogenesis | |
| History: History of evolutionary thought - Charles Darwin - The Origin of Species - modern evolutionary synthesis | |
| Subfields: population genetics - ecological genetics - human evolution - molecular evolution - phylogenetics - systematics - evo-devo | |
| List of evolutionary biology topics | Timeline of evolution | Timeline of human evolution |