EVOLUTION

What is Evolution? Evolution is the relative change in the characteristics of populations that occurs over successive generations

Diversity of Life Diversity is the cornerstone of evolutionary biology Not all individuals of a species are exactly alike Differences between individuals are not always immediately visible Diversity is important for the long term survival of a species

Biodiversity Differences in characteristics between individuals may be: Advantageous Harmful Neutral Characteristic may not give an individual an advantage now, but may become critical for survival later if the environment changes

What controls the characteristics of individuals? Genes!! There are different versions of genes, known as alleles, in a population which is the basis of biodiversity. Gene pool – total of all genes in a population

What is Evolution? Evolution is the relative change in the characteristics of populations that occurs over successive generations any shift in the gene pool of a population ratio of characteristics in a population change over successive generations

Who can evolve? Individuals cannot evolve! Individuals cannot change their genes. Populations are the smallest unit that can evolve. Populations can have a shift in their gene pool.

Why would populations evolve? So that a population becomes better suited to its habitats. Increased survival Better chance of passing on characteristics to offspring. Takes place over many generations.

How does a population evolve? A shift in the gene pool so that a higher ratio of individuals have a particular adaptation. Adaptation a particular structure, physiology or behaviour that helps an organism survive and reproduce in a particular environment. e.g. camouflage, superb sense of smell, bill shape

Example of a population that evolved: Peppered moths in England