1. "nothing in biology makes sense except in the light of evolution” ~Theodosius Dobzhansky (1900- 1975) Photo by “davemee” flickr creative commons

2. Charles Darwin developed the Theory of Evolution by Natural Selection which explained how populations of organisms changed over time (i.e. adapted)

3. Darwin’s Theory of Evolution by Natural Selection 1.Genetic variation exists among individuals in a population of a species. The variation is a result of mutations & sexual reproduction. 2.Population is exposed to a selection pressure. Individuals will compete for resources (food, mates, space) or be exposed to predation, parasites, disease or natural disaster. 3.Competition leads to the death of some individuals while others having advantageous variations (adaptations) will survive. 4.Individuals more likely to survive will reproduce more often, thereby contributing more genes to the next generation. 5.Over many generations (long periods of time), the genetic makeup of the population will change and the population evolves.

4. Say in a species of blob….there exist blobs of all shapes and sizes (variation) Blobs eat the little purple organisms that live underground and on the surface.

5. During a particularly hot year, food became less abundant (competition). Blobs with pointier noses that had the ability to dig into the soil to get food, hence they had a better chance of survival. Many blobs died that year…….

6. The ones that survived mated and passed their genes to the next generation (reproduction).

7. The next generation had more blobs with the pointed noses. That is NATURAL SELECTION. 1.Variation 2.Competition 3.Survival 4.Reproduction 5.Time

8. In science, theories are statements or models that have been tested and confirmed many times.

9. “Evolution by natural selection, the central concept of the life's work of Charles Darwin, is a theory. It's a theory about the origin of adaptation, complexity, and diversity among Earth's living creatures. If you are skeptical by nature, unfamiliar with the terminology of science, and unaware of the overwhelming evidence, you might even be tempted to say that it's "just" a theory. In the same sense, relativity as described by Albert Einstein is "just" a theory. The notion that Earth orbits around the sun rather than vice versa, offered by Copernicus in 1543, is a theory. Continental drift is a theory. The existence, structure, and dynamics of atoms? Atomic theory. Even electricity is a theoretical construct, involving electrons, which are tiny units of charged mass that no one has ever seen. Each of these theories is an explanation that has been confirmed to such a degree, by observation and experiment, that knowledgeable experts accept it as fact. That's what scientists mean when they talk about a theory: not a dreamy and unreliable speculation, but an explanatory statement that fits the evidence. They embrace such an explanation confidently but provisionally—taking it as their best available view of reality, at least until some severely conflicting data or some better explanation might come along. The rest of us generally agree. We plug our televisions into little wall sockets, measure a year by the length of Earth's orbit, and in many other ways live our lives based on the trusted reality of those theories.” David Quammen, National Geographic Magazine, November 2004

10. In science, the term "Theory" does not express doubt They explain a wide variety of data and observations They can be used to make predictions They are not absolute, can be changed as new evidence is found

11. Why do so many different animals have the same structures, the arm bones in a human are the same bones as a flipper in a whale? Why is the sequence of DNA very similar in some groups of organisms but not in others? Why do the embryos of animals look very similar at an early stage?

12. Photo courtesy of Swamibu, Flickr Creative Commons

13. Lamarck's Theory of Acquired Characteristics gain or loss of physical features due to overuse or underuse, respectively Eg. Ancestral giraffes stretched their necks to access higher branches, so their offspring inherited longer necks Evidence does not support this theory Photo courtesy of ucumari, creative commons, flickr

14. Darwin was a naturalist who, as a young man, traveled the world aboard the H.M.S. Beagle He collected specimens of many species, wrote prolific observations and made many sketches

15. Marine Iguana, photo courtesy of mtchm, flickr creative commons Blue-footed booby, photo courtesy of stirwise, flickr creative commons

16. Giant tortoise, photo courtesy of Planetgordon, flickr creative commons Finch, photo courtesy of stirwise, flickr, creative commons

17. Darwin noted that there existed many finches on the islands, but while they had similarities, each was adapted to eating a particular type of island food He concluded that the finches all came from one ancestral species and evolved into many new species

19. Darwin accumulated a great deal of evidence and eventually published his theory explaining the variety of species that exist on the planet “Theory of Evolution by Natural Selection ”

20. Fossils Shows numbers of extinct animals Shows similarities between extinct animals and animals that are alive today The earth’s layers show a time scale of species and when they appeared on earth (and when they died out)

21. Biogeography

22. Homologous structures – these are parts of the body that are similar, but have different functions  The flippers of whales, and the wings of birds  All forelimbs of vertebrates have the same pattern of bones  Common ancestry

23. Vestigial Organs – these are organs or parts that seem to have no function Whales have pelvic bones that do not attach to legs

24. Biochemistry and DNA When comparing the DNA of one species to another, more similarities are found in species that are more closely related. Lion photo credit: ucumari Tiger photo credit: digitalART2

25. Embryological Development Embryos of different species develop in almost identical ways. Human fetus at 8 weeks

26. Direct observation of species change 1. Bacteria become resistant to antibiotics 2. Wolves were bred over many generations to become dogs (artificial selection) and then bred further to create a variety of breeds

27. Creationism, sometimes referred to as “creation science” or “intelligent design” is the belief that organisms were placed on this earth by a divine being (God). It is NOT a theory because it does not follow scientific principles theories require evidence, and must be based on NATURAL PHENOMENON Finding gaps in our knowledge about evolution is a normal part of the scientific process, the existence of these “gaps” and questions does not qualify as evidence that an alternative theory must be correct

28. Many religious organizations do not have a problem with evolution, and it is compatible with their faith and beliefs. Ask your religious leaders what their thoughts are. Also see the National Center for Science Education for a list of statements from a variety of religious groups.National Center for Science Education