So we come to Darwin

1. So we come to Darwin • First into medical school (forced by his parents) • Then, after dropping out, into the seminary • Finally he found his love of taxonomy and entomology and went to go study it • Darwin set sail aboard _____ ___________(thanks to someone he met while getting his degree in theology at Cambridge). They left in December 1831

2. A theory is born • Charles Darwin loved Knowledge… even when on the Beagle he was learning… this time geology • His first landmark philosophy was that _________________________ __________________________________________(theory of uniformity) • Darwin combined the knowledge of plate movement, with fossil records and current fauna and thought, and thought • In the 1840s he had finally developed his theory ________________________ __________________________________________________________ • He sat on his theory until competition forced him to publish it

3. Darwin Returns to England • With all of his data Darwin returns and starts conferring with his collogues about what it all means • Glyptodonts and Armadillos gave him insight to the possibility of ____________ ______________________ • Galapagos Finches helped him to see the formation of a niche and ___________________ _____________________________________________

4. Thomas Malthus’ influence • Said that ______________________ ___________________… thus disease, famine, homelessness continued • These things are all caused, or continued from a lack of resources (Darwin believed that ___________________________ ______________________________) • This lack of resources causes a dying curve as they develop and only a select few will make it to reproductive age alive and viable! **Humans break this rule and are suffering the consequences of it

5. Two more important factors • Darwin noticed, and you can too, that the __________________________________________________________ • Offspring resemble their parents in a way that shows there is something that is passed on… a ______________ (before genes were understood) • _____________________________________________________________________________(thanks Wallace) _________________________________________________________________(to survive and reproduce)

6. Putting it all together • Of the multitude of characteristics, those that helped an individual survive to reproductive age were passed on more often • Reproduction is ____________! • Overtime the ____________ _________________and those that are not disappear altogether • THIS CONCEPT IS CALLED NATURAL SELECTION • Example: Butterfly and pollution

7. Competition: good then, good now • Darwin was a thoughtful person… Over the 10 years before the publishing Darwin kept thinking. • When competition finally forced him to publish his book he had strong evidence, and good, logical arguments • ____________________________________________________________________________________________________________________ • This vision gave/ gives rise to the total concept of evolution… which has itself evolved over the years… but we’ll get to that later

8. Fossils • The key to the past… bones and other well preserved tissues can be the key to the evolutionary path • The fossil record sets fossilized life ________________________ • The fossil record gives us a lot of the information that is used as support for evolution • Earliest fossils were interpreted through the prism of cultural beliefs, and have had to be reinterpreted since.

9. Fossilization • Fossils are made when hard bones, teeth, etc are buried and become stone hard over many years • ________________________________________________________________________________________________________________________ • The layers on the top were considered more recent, and the deeper the layer the older the fossil • This ______________, using the stratification was as good as possible but did not necessarily correspond on different continents all around the world.

10. Interpreting Fossils • Recently the process for determining age has improved with technology • Now use ___________________ • Use the half life of an element (the time it takes half of the radioisotopes to decay to their stable state) to tell the age of a fossil • The most common way to date young fossils is using ___________. • All fossils contain carbon, which exists as C12 most of the time but sometimes as the isotope C14 • As time passes the C14 decays into C12. By studying how much C14 is present in a fossil you can determine its age • Carbons half life is 5,370 years

11. Macroevolution looks at evolution over a greater time span • Uses the ______________________… a history of the earth with all the major species that have inhabited it. • Lists the origin of the earth at ________________ _______________________________Years ago!!! • Divided into _______________________that mark the major species and climate of that time. • Ages and relative ages are determined using radiometric dating… uses the half life of an element to determine the approximate age of the specimen.

13. Continental drift and Pangaea • Based on fossil evidence, especially of the Jurassic period, there is substantial evidence for the super continent _________________ • It was not the first position nor is the current position a final destination for the continents. • _______________________and ___________________continue even today • The concept of being once one, explains the divergent but similar species found all around the globe • Lungfish • Marsupials (Australia's “mammals”)

14. Plate Tectonics: the study of continental movement • There are many major plates within the earth’s surface • These plates can push away from each other, or run into each other spurting volcanoes, or driving up mountains • Volcanoes can from islands and more room for bio-diversity • Colliding continents on separate plates can give rise to enormous mountain ranges like the Himalayas (in India)

15. Phylogenetic trees show evolutionary history • Way to organize the historical information we have based on radiometric dating, DNA evidence, etc. • The bottom-most is the most primitive, ___________________ ____________________________________________________________ • The more branching events the farther diverged the species

16. When tracing evolutionary history, there are many techniques • Darwin used these techniques for his evidence and arguments • Biogeography • Comparative Anatomy • Some came into common use after Darwin’s time • Comparative embryology • Molecular biology We already talked about these, but a quick review These techniques came later and, like radiometric dating improved technique

17. Need to keep homology and analogy separated • Homologous structures imply a common ancestor. (________________________) • Analogous structures look similar but have __________________________________ … they were independently generated

18. Comparative embryology • Checking evolution by looking at how we start… all the final creatures look very different but they start the same way. • Its like two students turning in two essays that are ALMOST the same… they are different fonts, different margins, even have the paragraphs in a different order but if you look beyond into the content you can see they came from the same paper (that’s what comparative embryology tries to do)

19. Molecular Biology • Perhaps the best evidence for evolution • Actual compares the DNA of different species… _________________________________________________________ • Shows the progression of common ancestors (remember evolution is NOT LINEAR!!!)

20. Trees are works in progress • With new technology we have more accurate pictures of the phylogeny of many species • Now use protein sequences as well and DNA and RNA comparisons. • The people who spend their life classifying organisms based on their phylogeny are systematists… they usually focus on one family, order, class or phylum

21. Systematists have many tools • Deciding which phylum belongs in which class, or which species are part of which family is tricky business of guess and check • Because the information always changes so do the trees • Organize phylogeny into _____________________________ charts that show the evolution of one thing from others and identifies the derived characters it acquires along the way • Involves a quest for the simple answer… which is probably the right answer… parsimony

22. Systematics depends on phylogeny • All animals based on their clade and phylogeny are placed into taxa… • They are distinguished from one another and classified according to their history and current features

23. Classifications start with Domains and Kingdoms • Although the exact number of each is debatable all living things fit into one of 3 domains and 1 of five kingdoms based on what they have in COMMON • The reason for debate is Protista a kingdom based on not being in the other kingdoms, not on having a common feature