Theory of Evolution

1. Theory of Evolution Chapter 16

2. Idea of Evolution • Charles Darwin (1809-1882) • English ________________ • Took a trip around the world on a ship called________________ Mostly fascinated with the ________________ Islands • Best known for his theory of ________________ by natural selection

3. Darwin’s Journey • Began in ________________ • Sailed on a ship called the H.M.S. Beagle • Five year voyage sailing around the coast of ________________ ________________ and ________________

4. Observations Aboard the Beagle • Darwin collected 68 species of ________________ • Wrote about the different characteristics of habitats and species that live there • Species vary ________________ • There are similar organisms around that world with similar ecological ________________ • Ex: Rhea birds in S. America and ________________ in Africa

5. Observation Aboard the Beagle • Species vary ________________ • Related animals species often occupy different habitats within a ________________ area • Ex: Tortoise ________________ ________________ among Galapagos Islands

6. Observation Aboard the Beagle • Species vary ________________ ________________ • Some fossils of ________________ animals were similar to living species • Ex: Armadillo ________________ compared to modern day armadillos

7. Darwin’s Findings • Galapagos Islands • Groups of animals ________________ from island to island • Ex: tortoises on each island resemble each other but differ in the shape and function of their ________________ • Ex: finches on each island resembled each other but differ in the shape and function of their ________________ • Darwin believed these unique animals all came from a ________________ ________________ and they changed/adapted to their environment

8. Idea of Evolution • Evolution • Development of new types of organisms ________________ ________________ • Heritable ________________ in the characteristics within a population from one generation to the next

9. Ideas of Darwin’s Time • Scientists thought all species were ________________ and unchanging • The Earth was believed to only be a few ________________ (not billions) of years old • During Darwin’s time, new research was being done to figure out the ________________ of the Earth

10. Ideas that Influenced Darwin • James Hutton was a geologist in 1700’s • Made connections between mountains, valleys, and layers of ________________ • Believed the ________________ was older than thousands of years -- a time so old for the human mind to image • The Earth changes very ________________ and some layers can accumulate as the environment is changing

11. Ideas that Influenced Darwin • Charles Lyell was a English ________________ that believed the Earth’s surface continues to change • He explained that past processes that occurred are still occurring now • Ex: ________________ erupted in the past and still today • Published a great work called ________________ ______ ________________ in 1830 that built on the work of Hutton • Darwin read this book while on his journey around the world

12. Ideas that Influenced Darwin • Jean-Baptiste Lamarck • French naturalist that ________________ the idea that populations of organisms change over time

13. Ideas that Influenced Darwin • Proposed two hypotheses: Called Theory of ________________ ________________ • Organisms could ________________ during their lifetime by using or not using selected parts of the body • Individuals could pass these ________________ traits on to their offspring • Ex: Giraffes could ________________ their neck by stretching over a period of time to get the height they needed to eat and survive and then pass the longer neck trait to their ________________

14. Ideas that Influenced Darwin • Thomas Malthus was an English economist in the 1790s • Reasoned that if the human population grew continuously, there would not be enough ________________ for everyone • His reasoning explained why plants and animals produced more a high amount of ________________ since a portion will not ________________ due to environmental factors • Ex: Maple tree produces ________________ of seeds each summer • Ex: Oysters produce ________________ of eggs each year with the understanding that only a fraction will survive

15. Darwin’s Ideas • Around the same time Darwin and Wallace formed ________________ to explain evolution • Darwin was able to publish his book first called _______ _______ _____________ ______ ____________in 1858 • Book explained how evolution occurs by means of ________________ ________________

16. Artificial Selection • Darwin studied ________________ breeders • Farmers would select to breed only _____________ with the largest fruit, or the _____________ that produce the most milk • Darwin called this process ________________ ________________ • Nature provides the ________________, and humans select hose they find to be useful and allow them to breed and pass on ________________ to offspring

17. Evolution by Natural Selection • Mechanism from descent with _____________ • 1. Struggle for Existence • Organisms produce more offspring than can _____________ • Ex: grasshoppers lay over 200 _____________ at a time, but only a fraction survive • 2. Variation and Adaptation • Traits vary within a species and their environment called _____________ • These adaptations help increase _____________ to survive • Ex: _____________ with coral snake and scarlet snake

18. Natural Selection (cont’d) • 3. Survival of the Fittest • Organisms best _____________ for an environment will survive best and _____________ • The ability for an organism to _____________ and pass on adaptations • 4. Natural Selection • Process by which organisms with _____________ most suited to their local environment survive and leave more _____________ • Organisms _____________ their mate based on desired traits

19. Common Descent • Idea that every species must have ___________ by reproduction from pre-existing ___________ that arrange over time • Ex: finch ___________ at Galapagos • All species – living and extinct – are descended from ancient _____________ ancestors

20. Transitional Species • Organisms with features that are _____________ hypothesized ancestors

21. Age of the Earth & Fossils • Noted that fossils of extinct animals _____________ living species • Relative Age • Age _____________ to other fossils in order of old to young • Absolute Age • Using radioactive dating to get _____________ _____________ age

22. Age of the Earth and Fossils • Age of the Earth • Geologists are certain based on evidence via radioactive dating to indicate the Earth is about _______ _____________ years old • Fossils • _____________ of an organism that died long ago • Many fossils form a series that can trace back to an ancient extinct _____________ • Superposition • Idea that _____________ form in layers where the layers closest to the _______are the younger than below

23. Biogeography • Study of where organisms live _____________ and where they and their ancestors lived in the _____________ • Darwin used this method when exploring islands and observed _____________ vary based on their _____________ • Closely related but Different • Darwin believed that the finches of the _____________ all came from a common ancestor in the _____________ • Over time, _____________ selection produced a variation of species of finches • Distantly Related but Similar • Darwin noted that organisms that are _____________ related and inhabit similar environments have _____________ qualities

24. Anatomy and Embryology • Anatomy: study of the __________ • Embryology: study of _____________ • Homologous structures • Anatomical structures that originated from the _____________ common _____________ • Ex: bones in arms of humans, penguins, alligator and bat • Related _____________ but _____________ may differ

25. Anatomy and Embryology • Analogous Structures • When structures have similar _____________ , but did not develop the same way • Ex: wings of bat vs. bird • Vestigial Structures • Organs that no longer serve a _____________ in an organism • Ex: human tail bone, appendix

26. Anatomy and Embryology • Embryology • Similar patterns of embryological _____________ provide further evidence that organisms have descended from a _____________ ancestor • Many animals look _____________ during development and produce _____________ tissue

27. Genetics and Molecular Biology • At the molecular level, the _____________ _____________ and homologous molecules provide _____________ of common descent

28. Phylogeny • _____________ among groups of organisms • Can make a “__________” of animals evolved • Trunk of the tree would represent species that are _____________ related • Branches represent a _____________ population or lineage

29. Caribbean Anole Lizard • Found in the Caribbean islands of Cuba, Hispaniola, Jamaica, and Puerto Rico • Each lizard species body type differs by their habitat • Ex: stocky body and long legged lizards are best adapted for tree truck environments, slender bodies and long tails are best adapted for grassy environments • Hypothesis #1: An ancestral anole species specialized for living on twigs originally lived on one island and later migrated to other islands OR • Hypothesis #2: Each twig-dwelling species evolved independently on each island from distant ancestor anole species

30. Evolution in Action • Biologists tested the hypothesis by comparing _____________ from the various species • DNA evidence supported hypothesis 2 that each lizard evolved _____________ on each island • Convergent Evolution • Process by which _____________ species evolve _____________ traits • Ex: twig-dwelling species came from different ancestors but evolved similar adaptations to their environment

31. Divergence & Radiation • Divergence evolution • Process by which the descendants of a _____________ ancestor diversify into species that each fit _____________ parts of the environment • Ex: All breeds of dog share a common ancestor with wolves

32. Divergence & Radiation • Adaptive Radiation • Pattern of diversity when a new population in a new _____________ undergoes divergent evolution

33. Coevolution • Evolution is on-going and many species may evolve _____________ • Coevolution • When _____________ or more species have evolved adaptations to each other’s _____________ • Ex: • Predator/Prey Interactions • Introduction of new species • Creating antibiotics