UNIT 1

1. UNIT 1

2. BIG IDEA 1 The process of evolution drives the diversity and unity of life.

3. Enduring understanding 1.A Change in the genetic makeup of a population over time is evolution.

4. Essential knowledge 1.A.1 Natural selection is a major mechanism of evolution.

5. Evolutionary Biologist Ernst Mayr • OBSERVATION # 1 • For any species, population sizes would increase exponentially if all individuals that are born reproduced successfully (pg 445, fig 22.8) • OBSERVATION # 2 • Nonetheless, populations tend to remain stable in size, except for seasonal fluctuations

6. OBSERVATION # 3 • Resources are limited • INFERENCE # 1 • Production of more individuals than the environment can support leads to a struggle for existence among individuals of a population, with only a fraction of their offspring surviving each generation.

8. OBSERVATION # 4 • Members of a population vary extensively in their characteristics; no two individuals are exactly alike (pg 445, fig 22.9) • INFERENCE # 2 • Survival depends in part on inherited traits. Individuals whose inherited traits give them a high probability of surviving and reproducing in a given environment • These individuals have higher fitness and are likely to leave more offspring than less fit individuals

9. INFERENCE # 3 • This unequal ability of individuals to survive and reproduce will lead to a gradual change in a population, with favorable characteristics accumulating over generations. • The environment determines which variations are more favorable. More favorable traits are thereby passed on to the population as a whole.

10. Darwin’s Theory of Natural Selection • Individuals with favorable phenotypes • More likely to survive and produce more offspring • Passing traits to subsequent generations • Evolutionary fitness is measured by reproductive success

11. Genetic variation and mutation play roles in natural selection • A diverse gene pool is important for the survival of a species in a changing environment • Form and Function

12. Environments • Evolutionary rate and direction depends on the stability of the environment • Article for opinion

13. Adaptation • Genetic variation that is favored by selection • Manifested as a trait that provides an advantage to an organism in a particular environment

15. In addition to natural selection • Chance • Random events • Influence the evolutionary process, especially for small populations. • What are some random events that can influence the evolutionary process?

16. Darwin’s ideas • Mendel’s ideas • Modern Synthesis –ideas from others – still expanding and evolving

17. Gene pools

18. Gene pools and Allele frequencies • Population – • A localized group of individuals that are capable of interbreeding and producing fertile offspring • May or may not be isolated

19. Gene pool • Aggregate of genes in a population at any one time • All alleles and all gene loci in all individuals of the population • Fixed allele – one allele exists at a particular loci (homozygous_ • 2 or more alleles for a particular locus in a population may be homozygous or heterozygous

20. Each allele has a frequency (proportion) in the population • Population of flowers with 2 alleles for color

21. Conditions for Hardy-Weinberg Equilibrium • For a population or an allele • (1) a large population size • (2) absence of migration • (3) no net mutations • (4) random mating • (5) absence of selection • These conditions are seldom met.

23. The Hardy-Weinberg principle describes genetic equilibrium • A. Godfrey Hardy, an English mathematician, and Wilhelm Weinberg, a German physician, derived this model in 1908 • B. The Hardy-Weinberg principle describes the situation of no evolution (e.g., genetic equilibrium) • C. p is the frequency of the dominant allele, and q is the frequency of the recessive allele; frequencies range from 0 to 1

24. D. p + q = 1; therefore (p + q )2= 1 • E. p 2+ 2 pq + q 2= 1; p 2is the frequency of the dominant homozygote, 2 pq is the frequency of the heterozygote, and q 2is the frequency of the recessive homozygote • F. Any sexually reproducing population in which the allele frequencies conform to this equation is at genetic equilibrium

26. 51.4 cont. • Laboratory Studies of Drosophila Foraging Behavior • Read section in text • Analyze fig 51.20 on pg 1120 • Migratory Patterns in Blackcaps • Read section in text • Create an approximate view of what the graph would look like if you knew the quantitative data

27. Natural selection favors behaviors that increase survival and reproductive success • Foraging Behavior • includes not only eating, but also mechanisms used to recognize, search for, and capture food items • Compromise between obtaining food and the energy spent or hazards faced when obtaining food (avoiding predators)

28. Foraging • Energy Costs and Benefits • Cost-benefit analysis of feeding behavior • Pacific Northwest crows and welk shells • fig 51.22, pg 1122 • Bluegill sunfish and Daphnia • Fig 51.23, pg 1123 • Risk of Predation • Influence of Predation risk on Foraging behavior • Idaho mule deer • Fig 51.24, pg 1123

29. Optimal foraging theory

30. Optimal Foraging Theory • There is a compromise between the benefits of nutrition and the costs of obtaining food • Costs include energy expenditures and risk of being eaten by a predator • Natural selection should favor foraging behavior that minimizes the costs of foraging and maximizes the benefits

31. http://www.thewildclassroom.com/biodiversity/birds/aviantopics/optimalforagingtheory.htmlhttp://www.thewildclassroom.com/biodiversity/birds/aviantopics/optimalforagingtheory.html

32. Mating Behavior and Mate Choice • Seeking or attracting mates • Choosing among potential mates • Competing for mates • http://www.bbc.co.uk/nature/adaptations/Courtship_display#p003x6x1

33. Mating Systems and Parental Care • Differs from species to species • Promiscuous • Remaining together • Monogamous • Polygamous – usually one male with many females • Polygyny vs polyandry • Figs 51.25, pg 1124 • http://evolution.berkeley.edu/evolibrary/search/lessonsummary.php?audience_level%5B3%5D=9-12&topic_id=&keywords=&type_id=&sort_by=audience_rank&Submit=Search&thisaudience=9-12&resource_id=100

34. Applying Game Theory • Pg 1127 • Read and summarize information • Side-blotched lizard • “Paper-Rock-Scissors”

35. The concept of inclusive fitness can account for most altruistic social behavior

36. Altruism • Selflessness • Squirrels • Bees • Naked mole rats • Pg 1128

37. Inclusive Fitness • In addition to altruistic behavior, close relatives or “kin” further their genes by inclusive fitness • Helping close relatives to produce offspring • Hamilton’s Rule – mathematical formula for • Applying a quantitative measure for predicting when natural selection favors altruism

38. Social Learning • Learning through observing others

39. Social learning • Mate choice copying • Alarm calls • Different sounds for different dangers • Fig 51.37, pg 1132

40. Evolution and Human Culture • Sociobiology • Certain behaviors occur because they are expressions of genes that have been furthered by natural selection • Edward O. Wilson – behavior is controlled more by our genes than learned behavior

41. Essential knowledge 1.A.1 To know: Benchmarks a – h See Unit Organization Handout