Theory of Natural Selection What is artificial selection? What are the four principles of natural selection?

Insights Leading to Natural Selection Artificial Selection – Humans select desirable traits and breed for them Future populations have a higher percentage of desired traits than “natural” population

Insights Leading to Natural Selection Struggle for survival Malthus proposed there were limits to human population (disease, food supplies) to keep population in check Darwin thought this also existed in nature

Natural Selection Organisms that inherit beneficial adaptations produce more offspring than other “less fit” individuals Also known as: Survival of the Fittest Descent with Modification

Four Principles of Natural Selection Variation – differences that exist naturally are basis for trait selection Overproduction – more offspring results in competition between offspring Adaptation – certain variations allow some individuals to survive better and reproduce more Descent with modification – As favorable adaptations accumulate over time, more individuals will have the favorable trait