INHERITANCE Variation G R Davidson

Variation Animals and plants reproduce to ensure the survival of their species. If any type of organism did not reproduce, this type or species of organism would become extinct.

Variation “Organisms belong to the same species if they can interbreed to produce fertile offspring.”

Variation Variation in a species is the differences which can occur between individuals of the same species. Human examples – height, pulse, blood type, hand span, etc.. This variation within a species can either be CONTINUOUS or DISCONTINUOUS.

Continuous Variation If the variation in a characteristic can be measured and it shows a wide range occurring between two extreme measurements – it is CONTINUOUS VARIATION.

Continuous Variation e.g. Shell diameter in limpets.

Continuous Variation e.g. human hand span

Continuous Variation e.g. weight

Continuous Variation e.g. Height

Discontinuous Variation If the variation in a characteristic shows a definite number of easily observed clear- cut types, the characteristic shows DISCONTINUOUS VARIATION.

Discontinuous Variation e.g. eye colour

Discontinuous Variation e.g. blood type

Discontinuous Variation e.g. flower colour

Discontinuous Variation e.g. ear lobes Attached lobeUnattached lobe