Evolution and Genes

Evolution Evolution is the sum of all transformations undergone by a particular primitive life form over time

Natural Selection Natural Selection is a theory developed by the scientist Charles Darwin to explain the evolution of species In this theory individuals whose physical and behavioural characteristics are best adapted to their habitat have a better chance of reproducing and passing on their characteristics

Genetic Mutation The nucleus of the cell contains the chromosomes that have the genes for that species A gene can become mutated so that it is different from “the normal form” Individuals who carry a beneficial mutation have a better chance of survival and therefore a better chance of passing on that gene through reproduction

Genes Genes carry instructions that produce a characteristic A characteristic is a physical, or non-physical property that can vary from one individual to another within the same species Each characteristic needs at least 2 instructions, called alleles

Together all of our genes make up our genetic code or DNA An individual gets his or her genetic code from his/her parents Half of the code comes from “Mom” and the other half from “Dad” Mom gives 1 allele for eye colour, Dad gives one allele for eye colour, 2 alleles = genetic code for eye colour

Dominant vs Recessive An allele (variation) for a gene can be either dominant or recessive Dominant alleles will be displayed, which means if you get even one of these alleles form a parent you WILL have that trait Recessive alleles will only be displayed if you get two (one recessive from mom AND one recessive from dad)