Causes of Variation
Interspecific - the variation that exists between different species. Eg. horses, vary from ducks.
Intraspecific - the differences that occr within a species. Eg. the length of a giraffes' neck.
Genetic Variation is inherited.
All members of a species have the same genes. Induviduals within the species have different versions of the gene - alleles.
The alleles make up the genotype.
The phenotype (appearance) of an induvidual is affected by the environment.
Eg. plant growth, fur colour, accents.
Variation is often a combination of genetics and the environment.