Darwins Principles AP Biology 2010 2011 Darwins finches

Darwin’s Principles AP Biology 2010 -2011

Darwin’s finches § Differences in beaks allowed some finches to… successfully compete u successfully feed u successfully reproduce u AP Biology § pass successful traits onto their offspring

In historical context § Other people’s ideas paved the path for Darwin’s thinking competition: struggle for survival population growth exceeds food supply land masses change over immeasurable time AP Biology

Voyage: 1831 -1836 November 24, 1859, Darwin published “On the Origin of Species by Means of Natural Selection” AP Biology

Essence of Darwin’s ideas § Natural selection heritable variation exists in populations u over-production of offspring u § more offspring than the environment can support u competition § for food, mates, nesting sites, escape predators u differential survival § successful traits = adaptations u AP Biology differential reproduction § adaptations become more common in population

Where does Variation come from? § Mutation u random changes to DNA § errors in mitosis & meiosis § environmental damage § Sexual reproduction u mixing of alleles § genetic recombination w new arrangements of alleles in every offspring § new combinations = new phenotypes AP Biology

La. Marckian vs. Darwinian view § La. Marck u in reaching higher vegetation giraffes stretch their necks & transmits the acquired longer neck to offspring § Darwin u AP Biology giraffes born with longer necks survive better & leave more offspring who inherit their long necks

Stick your neck out… Ask Questions! AP Biology