EVOLUTION Adapting to change!

Evolution Evolution is the sum of all transformations undergone by primitive life over time. Primitive life ~ 4 bya

Natural selection Natural selection is the process by which traits become more or less common in a population due to consistent effects upon the survival or reproduction of their bearers. It is a key mechanism of evolution. Individuals whose physical and behaviour characteristics are best adapted to their habitat have better chances of reproducing and passing on their characteristics to future generations. “Survival of the fittest”

Genetic Mutation A gene mutation is a permanent change in the DNA sequence that makes up a gene. Gene mutations occur in two ways: they can be inherited from a parent or acquired during a person’s lifetime. This completes the theory of natural selection and evolution of species (Eye color is a form of genetic mutation)

Genes and Chromosomes Genes are found in chromosomes Chromosomes are singular pieces of DNA, which contain many genes. It’s chromosomes and genes that determine individual characteristics

Chromosome are found in the nucleus of the cells of living organisms They are the blueprint of life Human cells contain 23 pairs of chromosomes for a total of 46 There are 22 pairs of autosomes and one pair of sex chromosomes. The sex chromosomes are the X chromosome and the Y chromosome Male (XY) Female (XX)

Dominant vs. Recessive genes Dominant genes are the ones that are expressed and visible. However, it is possible that a recessive gene (trait) might be visible if it is inherited by both parents.