EVOLUTION

EVIDENCE AND THEORY

CHAPTER 15

1. What is evolution?

• An orderly succession of changes.

2. What is biological evolution?

• The change in populations of organisms over generations.

Jean Baptiste Lemark(1744-1829)

• A encyclopedia author.

• Developed the word invertebrate.

• Was the first to propose a unifying hypothesis of species modification

4. Explain an acquired trait.

• Is a trait that is not determined by genes.

• It arises during an organism’s lifetime as a result of the experiences or behaviors.

• Ex. He believed that the webbed feet of shore birds resulted from the repeated stretching of the feet, not from an inherited gene.

3. What was Lamarck’s theory?

• Similar species descended from a common ancestor- thus, living species were descended from similar extinct species evident in the fossil record.

5. What part of Lamarck’s theory is useful today?

• He was the first to state that organisms change over time and that new types of organisms are modified descendants of older organisms.

Charles Darwin (a.k.a. Chucky-D)

• 1809-1882• Proposed that

species were modified by natural selection.

6. What is natural selection?

• Organisms best suited to their environment reproduce more successfully than other organisms.

• Organisms with favorable traits increase in population.

7. Who are the two scientists who proposed it?

• Charles Darwin

• John Henslow

8. Define population.

• An interbreeding single species group.

9. Describe Darwin’s background before his voyage on the beagle.

• He first attended medical school and was grossed out by the sight of blood

• Then he enrolled in school to be a clergy man, but was unable to council people.

• After failing at both he did not know what he wanted to do .

• Then he was offered the voyage of a lifetime……

• H.M.S. Beagle

• He was a naturalist for the expedition

• It was a 5 year mapping and collecting expedition.

• Toured South America and South Pacific.

10. What is uniformitariansim

• The idea that geological principles that guide earth today are the same that they have been in the past.

11. What did Darwin reason was an organisms response to the changing

environment?

• He reasoned that the changing environment changed habitats.

• A population would have to change also to survive.

12. What did he say about he pace of change?

• That it would be slow and hard to detect by humans

13. What was note worthy about he Darwin finches?

• Each finch species had a specialized bill suited for its diet.

14. What did Darwin conclude about the finches?

• That despite the bill, each finch was so similar he concluded that they must share a recent common ancestor.

• Meaning they were descended from the same species.

15.Where is Darwin’s theory explained?

• The Origin of the Species

• 1858

16. What are the two parts of Darwin’s theory?

• Decent with Modification

• Modification by Natural Selection

17. Explain “descent with modification”.

• Newer organisms in the fossil record are actually descendants of older species

18. Darwin reasoned that all living things…

• Are descended from one or a few original types of life.

19. What states how evolution occurs?

• Modification by Natural selection

20. What is the environmental affect on population growth?

• Environment limits the growth of populations by increasing the rate of death or decreasing the rate of production or both.

21. What determines if a trait will be passed on?

• If a trait both increases the reproductive success of an organism and is inherited it will be passed on.

22. What is fitness?

• An individual with high fitness is well adapted to its environment and reproduces more successfully than an individual with low fitness.

23. What is adaptive advantage?

• A favorable trait is said to give the organism a better chance at reproduction and passing on traits.

24. What is the effect of environmental change?

• It causes populations to rapidly adapt to new conditions, if the change is too extreme, and the population is unable to adapt, it will become extinct.

The Galapagos

Warm water penguins

Blue Footed Boobies!

Evolution in Process

1. Define homologous.

• Similar features that originated in a shared ancestor

• Example: beaks of birds; forelimbs of animals.

2. Give a specific example.

• The forelimbs of the penguin, alligator, bat, and human all derive from the same embryological structures.

3. Define analogous (features).

• Serve the same function and look some what alike. They derive from different structures in development.

4. Give one example.

• The wings of humming birds and humming bird moths.

5. Define vestigial feature.

• Apparently useless features, that no longer serve a function

6. Give two examples.

• Human tail bone, and appendix

• Snakes have limb bones

Whale of a tale

• Whales have pelvic bones

7 What clues do vestigial structures provide?

• Whales probably descend from a land animal that had legs.

• These structures show body parts which function is no longer necessary for reproductive success (survival).

7 What clues do vestigial structures provide?

• Whales probably descend from a land animal that had legs.

• These structures show body parts which function is no longer necessary for reproductive success (survival).

8. Define conserved.

• Genes have remained unchanged.

9. What is the significance of embryological studies in evolution?• Ontogeny recapitulates phylogeny

• Embryological development repeats a evolutionary history.

• In the EARLY stages all vertebrate embryos look alike.

10. Explain one similarity in macromolecules.

• Closely related organisms have similar macromolecules like DNA, RNA and the protein hemoglobin

What are the three patterns of evolution?

• 1. Coevolution

• 2.Convergent evolution

• 3.Divergent evolution

12. What is coevolution? Give on example.

• The change of two or more species in close association with each other.

• Predators and prey

• Plants and pollination animals

13. What is convergent evolution?

• When the environment selects similar traits even though the ancestral types were quite different.

• Ex Sharks and Porpoises

What is divergent evolution?

Two or more related populations or species become more and more dissimilar.

What is adaptive radiation?

• Many species evolve from a single species

16. What is artificial selection and its effect on a species.

• When the process of divergence is quickened artificially.

• It produces many times what could have been accomplished by nature.