1. Descent with Modification In 1859 Charles Darwin changed the ancestral view when he published on the Origin of Species. – In it he challenged the whole organism theory (organisms were created just as you find them today) offered by Aristotle and offered a new one. Organisms may be quite different than there ancestors due to natural selection.

2. Charles Darwin Charles Darwin set sail from England on the HMS Beagle in 1831 – With each stop he made collections of specimens and drawings of the life forms and plants that he came in contact with – He noticed that although the life forms found in different locations were similar, there were also differences

3. Adaptation to the Environment Darwin noted that the differences in the organisms that he observed were tied to the differences in the environment – Natural Selection… nature selects the phenotypes that are best suited to the environment Darwin supported this claim by the collection of fossils from the different locations

4. Natural Selection leads to Evolution Natural selection simply means that nature selects which phenotypes are most suited to leave offspring. – Those offspring will pass on the genetic traits that made them more fit (able to adapt to environmental changes). – Natural selection leads to evolution within a species. – Evolution of a species is the change in gene frequencies in a population over time. It leads to evolutionary adaptation which is an accumulation of adaptations that lead to an increase of fitness. This descent with modification became the focus of now classifying organisms trying to find a common descent.

5. Galapagos The Galapagos islands are a chain of closely located islands which create species isolation and which have very different ecological pressures. – The different pressures lead to rapid speciation of its inhabitants through natural selection