Populations: Variation and Selection
Populations: Variation and Selection
- Individuals in a species population exhibit phenotypic variation due to genetic and environmental factors.
- The main source of genetic variation is mutation.
- Meiosis and random gamete fertilisation during sexual reproduction create more genetic variation.
- Predation, disease, and survival competition lead to natural selection, i.e. differential survival and reproduction.
- Organisms with phenotypically advantageous traits likely produce more offspring, passing beneficial alleles to the next generation.
- Differential reproductive success influences allele frequencies within a gene pool.
- Stabilising, directional, and disruptive selection also affect these frequencies.
- Evolution is portrayed as a shift in a population’s allele frequencies.
- A comprehensive model explaining evolution and natural selection is necessary and can be modified for different concepts.
- Practice papers are highly recommended for a thorough understanding.