LC BIOLOGY-Evolution and variation

Species

A group of organisms capable of interbreeding and producing fertile offspring

Variation

Difference between members of the same species

Causes of genetic variation

Sexual reproduction- independent assortment

Mutations

Mutation

A spontaneous change in the amount or structure of DNA

Mutagen

An agent that causes mutations

Gene mutations

Caused by a single change in a gene

Chromosome mutations

Caused by a change in the no. of chromosomes

Evolution

Living things change genetically to produce new forms of life over long periods of time.

Theory of natural selection

-too many offspring are produced

-this leads to competition all populations have genetic variations

-individuals that are best adapted to the environment survive

-as the environment changes new adaptations emerge

-over a long period of time new species form

Specification

Evolution leads to the formation of a new species

One evidence in support of evolution:

The fossil records, palaeontology ie. Change in tooth structure, feet structure

Taxonomy

The science of classifying organisms