DO NOW Look at the person sitting next to you. Are both of you of the same species? Why or why not? What does it mean to be of the same species? ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Evolution and Natural Selection
Diversity, Variation and Evolution Living organisms are both similar and varied. Organisms can be very different (a flower and a tree; human and a horse), yet they share similarities.
Every organism must have some type of way of: Obtaining Energy Reproducing Exchanging substances with the environment
Unity of Pattern There is a unity of pattern in the structures and functions of different organisms. Unit of pattern in DNA- only one basic genetic code for all organisms, including humans
Can also be seen in the structures of various organisms. Vertebrates provide a good example Even the most diverse types of vertebrates have relations.
Reproductive and developmental processes also have unit of pattern
All organisms are grouped into species Reproductive Isolation Organisms that are so closely similar that they can mate and produce fertile offspring are grouped in the same species. The inability of one group to interbreed successful with any other group is reproductive isolation. Polar bears and brown bears have been successfully mated in zoos, but no such cross has been found in the wild. Why not?
Variations Sometimes, organisms in the same species may not look like one another. Not all dogs look alike, but they can interbreed Usually done easily, but dogs such as a Great Dane and a Yorkie will have difficulty. Variations are differences among individuals of a species. Not all humans look the same
Variations
Darwin and the Galapagos Islands In 1831 Charles Darwin started his voyage on the H.M.S. Beagle. He studied South America and islands in the Pacific. The Galapagos Islands are off of the coast of Ecuador.
Darwin studies many forms of life on these Islands, but most famously finches and tortoises. He continued to study these organisms when he returned to England.
https://www.youtube.com/watch?v=03YKT7ytJdE