1. Essentials of Physical Anthropology
Chapters 4 & 5

2. Genetic Variation Meiosis and genetic variation (recap)
cross-over (recombination)

3. Genetic Variation

4. Genetic Variation Cross-over Recombination Gene linkage
Haplotypes (genotypes inherited together during meiosis)

5. Genetic Variation Genetic Variation Cross-over (recombination)
Second cell division yielding haploid cells

6. Genetic Variation

7. Genetic Variation
Meiosis
Recombination
Haploid Cells

8. Genetic Drift (Founder Effect)
Chapter Four
Evolution
Mutation
Natural Selection
Genetic Drift (Founder Effect)
Gene Flow

9. Mutations (SNPs or Point Mutations)
Copying errors, or typos, in the DNA sequence
Can effect traits (phenotypes) Ex. Sickle Cell
Most have no effect at all
Inherited from parents, can be used to determine the degree of genetic relatedness between individuals

10. Example of SNP

11. Expression of SNP

12. Mutation Various kinds of “errors” can occur, including:
Frame shift mutation, yields protein with no function
Transposable elements, likely to have no effect, but can cause real damage depending on where it occurs.
Entire chromosomes can be effected by mutations.
Most extreme: trisomy or monosomy

13. Trisomy

14. Trisomy (Stella Walsh)

15. Trisomy (Caster Semenya)

16. Monosomy

17. Mutation
Not all mutations have negative health consequences! Some prove advantageous. Most are completely unnoticeable. And some have a neutral effect, though are apparent.

18. Mutations
The only mutations that matter in terms of evolution are…

19. Mutations
…the heritable ones!!

20. The Royal Disease
Queen Victory—1884 During her conception, mutation occurs causing her to become a carrier for hemophilia, but she is never ill from the disease. Prince Leopold inherits her mutated gene, and dies after falling down some steps. Why did Queen Victoria’s son die from hemophilia, while she was never afflicted?

21. Natural Selection Evolution = change in allele frequency over time
Always variation and competition
Whether trait is advantageous or disadvantageous will determine allele frequency
Eventually, advantageous traits should become more common within the population

22. Natural Selection
Mammoth Elephants

23. Natural Selection Directional (favors the extreme)
Is about fitness, and includes various types:
Directional (favors the extreme)
Stabilizing (favors the average)
Disruptive (can lead to speciation event)

24. Natural Selection
natural-selection-humans

25. Balanced polymorphism
Natural Selection
Sickle Cell Anemia
Trade offs
Positive selection
Balanced polymorphism

26. Genetic Drift
As long as there is no selective advantage (or disadvantage), change is RANDOM.
Alleles are either lost or fixated (coin toss)
Uneven ratio of alleles less likely in large pops, more likely in small pops
Drift is more likely in small, endogamous groups.

27. Founder Effect

28. Founder Effect

29. Founder Effect
How was Huntington’s Chorea passed so successfully among these communities if it is a dominant allele, only one of which is required for phenotypic expression?

30. Gene Flow Interbreeding across populations (admixture)
Accessibility! Proximity is connected to genetic relatedness.
Clinal change (blood type)
Socially influenced!

31. Gene Flow

32. Gene Flow
Vikings originate from three countries of Scandinavia: Denmark, Sweden, and Norway
Age of the Vikings: AD
Carriers of recessive allele for red hair

33. Gene Flow

34. Gene Flow

35. Gene Flow

36. Gene Flow
Why didn’t the Vikings stay and share their DNA with the Native Americans?
Did not have the resources
A difficult trip across the Atlantic
Saw more material gain in Europe

37. Hardy-Weinberg Equation

38. Hardy Weinberg Equation
p2+2(pq)+q2 = 1
Conditions:
No mutation
No natural selection
No gene flow
Population is large (genetic drift)
Mating is random
All members produce same number of offspring

39. Hardy Weinberg Equation
If we apply this equation at different points in time, we can see if evolution is operating on a particular gene.
If evolution is occurring, then one of the four forces of evolution is in effect.

40. Chapter 5
Homeostasis: how the body maintains internal stability in the face of external stress or change.
Humans are very good at this (i.e., adaptable)
This adaptability enhances human diversity and vice versa

41. Chapter 5 Humans have unique life histories (big brains)
Functional adaptation (skin tanning, cold/heat)
Genetic adaptation (melanin sites, body shape)
101/lecture/QqTLE/4-3-adaptation-of-high-altitude-peoples
Cultural adaptation (shelter, clothing, etc.)

42. Chapter 5
Cline: gradual continuum of change rather than discrete, bounded categories of difference.

43. Chapter 5

44. Chapter Five

45. Chapter 5

46. Chapter 5