EVOLUTION REVIEW

1. EVOLUTIONREVIEW

2. HOW could a bottleneck result in evolution of a population? Because of the small sample size, random events may reduce the population unevenly so gene frequencies change =evolution.

3. What is a scientific theory? Our best current explanation – well tested and covers many phenomena Why is each of these not a scientific theory? only tested once – not repeated Cold fusion Males that score higher on biology tests are preferred by females very narrow = does not cover many phenomena

4. no. of bacteria amnt. of antibiotic required to kill the bacteria If you were to graph the size variation in a population of fish, what would you expect the graph to look like? (Label your axes.) Now draw the graph showing variation in how much antibiotic it takes to kill streptococcus bacteria.

5. 19-20 21-22 15-16 17-18 19-20 21-22 23-24 Which of these shows the greatest variation? the first one

6. What are the four steps required for natural selection to occur? • Genetic variation in the population • Must be a struggle for survival • Some survive and reproduce better than others • The frequency of the successful gene increases • in the population Use these four steps to explain how frogs evolved webbed feet. • Some frogs have more webbing than others • They must swim fast to avoid predators • Frogs with more webbing survive better than others • The frequency of webbed feet increases in the population. Do “webbed feet” fit the definition of an adaptation? Yes – It is genetically controlled, helps an organism survive in a watery environment, No – Does not tell the environment.

7. How does this diagram provide evidence of evolution? Embryological Evidence – All vertebrates have gill slits, yolk sacs and tails. We would expect such similar features from organisms that have evolved from a common ancestor.

8. A change in gene frequency in a population over time = ? EVOLUTION

9. What type of selection is shown here? Disruptive selection

10. What are the three requirements for an adaptation? • Genetically controlled • Helps on organism survive • In a particular environment Give an example of an adaptation. Reptiles eggs have a leathery covering to prevent drying out when laid on land

11. Artificial? Natural? Or Sexual Selection? N Predators choose which ones survive/reproduce S Potential mates choose which ones reproduce A Humans choose which ones reproduce Waxy leaves make it difficult for some insects to eat the plant. N A S

12. Artificial? Natural? Or Sexual Selection? Natural

13. Artificial? Natural? Or Sexual Selection? Artificial

14. The trait for 'male-pattern baldness' is a recessive trait encoded for by "b". Non-balding is encoded for by a dominant allele encoded for by the letter "B". A street survey conducted by Hair Club for Men found that out of 1000 men, 360 had male pattern baldness, the other 640 did not Using this information find the allele frequencies for "B" and "b." b = .6 B = .4 What are the expected genotype frequencies ? BB = 0.16 Bb = 0.48 bb = 0.36

15. How does this provide evidence of evolution? Homologous structures are ones that have the same structure even though they have different functions indicating a common ancestor.

16. A B B C Y Y A C Convergent or Divergent Evolution? A species spreads into two or more different environments where natural selection acts differently on the organisms in each environment. D Butterflies and birds both evolved wings. D C C Two different species become MORE similar because they are in the same environment and natural selection acts on them in the same way. C

17. Define species. A group of organisms that can interbreed to produce fertile offspring

18. Birds? Dogs? Fish? Mules? Which of these is one species? Dogs are all one species

19. Fossils show that only the simplest organisms were here on earth in the early geological time periods. More and more complex organisms appeared as time passed. This supports the theory that one species evolved from another. How does this provide evidence of evolution?

20. Reproductive isolation is necessary in order for _________________ to occur. speciation

21. What type of reproductive isolation is illustrated here? behavioral geographic temporal What are the other types of isolation?

22. Who said it did? Lamarck said that organisms can acquire traits that they “need” and pass them on to their offspring.

23. What type of selection is shown in this graph? Directional Selection

24. How do the leg bones in baleen whales provide evidence of evolution? The leg bones in baleen whales do not have a function. They may be “left over” from an ancestor that did use them.

25. What type of selection is shown here? Balancing/stabilizing

26. Is this a good example of an adaptation? WHY? Or WHY NOT? Does not help them survive Freckles in humans A squirrel learning to stay away from the neighbor’s vicious dog. Is not genetically controlled Extra layers of insulating fat. Yes - for cold environment. No - for warm environment.

27. What type of isolation is illustrated here? Geographic What are the other types of isolation? Behavioral & Temporal

28. Genes Are Lost in Small Populations Just by chance, genes carried by the parents might not be passed on to their offspring. Each offspring gets one gene from its mother, the other from its father.Which gene is chosen is determined by chance. In this example, the parents carry three different genes for a particular trait: a, A and B. By chance they pass on only a and A to their offspring. Gene B is lost due to random chance. In this example, on the average: a will be lost 6% of the time A will be lost 25% of the time B will be lost 25% of the time Which mechanism of evolution is this an example of? Genetic Drift – chance changes in small populations

29. How does this table help provide evidence of evolution? The DNA of organisms that are closely related is more similar than the DNA of organisms that are distantly related. This is biochemical evidence of evolution.

30. List SIX types of evidence of macroevolution. FOSSILS Homologous OrgansAnalogous Organs VESTIGIAL ORGANS Comparative Embryology COMPARATIVE BIOCHEMISTRY

31. Why is selection for the sickle cell trait different in the US and in Africa? In Africa there is an advantage to having sickle cells, it helps disrupt the life cycle of the malaria parasite.

32. species form slowly and continually species form rapidly, in uneven bursts Name these theories of evolution Punctuated Equilibrium Gradualism

33. The island of Surtsey (Iceland), has been a unique opportunity for scientists to monitor evolution since the day it emerged from the sea in 1963. The once barren volcanic island preserved from human interference is now crowding with plants, insects and birds. Which mechanism(s) of evolution have been at work here? Explain. Founder Effect! Probably also natural selection and other.

34. What is speciation? Speciation occurs when one organism gives rise to another. Differentiate between microevolution and macroevolution. Microevolution is small changes within a species. Macroevolution involves large changes that result in formation of new species, families, kingdoms, etc.

35. Please use sexual selection to explain how the corn snake may have evolved its bright color. Now use natural selection to explain how the bright color may have evolved. Now use artificial selection to explain how the bright color may have evolved.

36. Which mechanism of evolution is illustrated above? Gene flow (migration)

37. What do you know about Charles Darwin – What is his famous theory? On what ship did he sail around the world? What is the name of his most famous book? Natural Selection HMS Beagle On the Origin of Species

38. Identify 4 sources of variation in a population. Mutation Crossing Over Independent AssortmentFertilization