1. Biological Anthropology
Chapters One and Two
The Essentials of Physical Anthropology

2. Evolution
“The gradual development of something. Advancement, progress, expansion, growth.”
“The physical, mental, and biological transformation of a species in order to adapt to a living environment.”
“Becoming more conscious/aware.”
“[Evolution is] the change of an organism over time. [It] is caused by many factors: natural selection, mass extinction, adaptation, etc.”
“[Evolution is how humans] developed from cavemen.”
“Natural progression of people.”

3. Evolution Evolution does not equal development/progress.
“Survival of the fittest” misunderstood.
Evolution is about how change occurs over time among organisms/life.

4. Evolution
“How living organisms have changed, or adapt, over time due to environmental and cultural changes.”
“…It refers to the ‘survival of the fittest’... Creatures who have adaptive behaviors and attributes tend to survive.”
“The way people, animals, and things change as time passes. They can either grow into more things, or stay the same.”

5. Evolution
“Evolution is how we became who we are today from our ancestors.”
Evolution is based upon the principle that all organisms share a common heritage, and more closely related organisms share a more recent common ancestor.
Human/primate evolution

6. Chapter One Marco Polo 1200’s Asia
Christopher Columbus late 1400s Americas
Scholars begin speculating about these cultural differences: Anthropology

7. Chapter One Linguistic, Cultural, Archaeology, Biological (Physical)
Unifying theme: CULTURE!!!
Culture=learned behavior transmitted person to person, generation to generation (language)

8. Chapter One Why does biological anthropology incorporate culture?
What separates humans from other animals (and primates)?

9. Chapter One
CULTURE!!!

10. Chapter One
You cannot study the evolution of the human species without investigating us both as cultural and biological beings!

11. Chapter One BIOCULTURAL APPROACH
Biological physical anthropology examines the biological evolution and biocultural variation of human beings (h. Sapiens).

12. Chapter One
Biocultural variation is the outcome of unique life histories.

13. Biocultural Variation

14. Biocultural Variation

15. Biocultural Variation

17. Biocultural Variation

18. Biocultural Variation

20. Genie

21. Chapter One
So what separates us?

22. Chapter One Bipedalism Non-honing chewing Material culture Hunting
Speech
Domestication of plants and animals (10-11,000 years ago)

23. Chapter One
All features are a product of the complex interaction of biology and culture.

24. Chapter One We are all dependent on culture for survival.
Social learning is key element of human evolution!

25. Chapter One
How do biological anthropologists acquire facts about human evolution?

26. Chapter One

27. Chapter One

28. Chapter One
Scientific method=knowing through observation of natural phenomena
Empirical
Self-correcting

29. Natural Selection Natural selection (Darwin’s idea)
A given trait or behavior can be “selected for” if it somehow enhances an organism’s survival and reproduction.

30. Natural Selection Presupposes three things:
1.) Variation—at least two traits. Options to create opportunity for selection to occur.
2.) Heritability—parents pass on traits through genes.
3.) Differential mortality—Probability of survival is somehow effected directly by this heritable (inherited from parents) trait.

31. Peppered Moth

32. Natural Selection

33. Evolution Myths

34. Chapter Two
1800s “World discovers itself through collections” (Larsen 2014:23).
This period of discovery lays the foundation for Darwin’s idea: descent with modification (parents pass traits from parents to offspring).

35. Chapter Two
Scientists from various disciplines (geology, paleontology, taxonomy, systematics, and demography) lay the foundation for evolutionary biology, which Charles Darwin founded.
These scientists helped correct three popular misconceptions about earth and its inhabitants:

36. Chapter Two
Scientific realizations: 1.) The earth is ancient (Hutton and Lyell) 2.) The surface of it has changed a lot 3.) Plants and animals have changed a lot (Hooke and Cuvier)

37. Chapter Two
Darwin discovered the primary process by which this change has taken place: natural selection.

38. Chapter Two
Species show variation between members because organisms adapt to their habitat.
Through cycles of reproduction, characteristics that enhance survival and reproduction within a given habitat/environment increase in frequency.
This is natural selection, and it can lead to increased variation within a species.

39. Chapter Two
Adaptive radiation: an ancestral group of organisms become more varied as members of the group adapt to specific environmental niches, leading to new forms of that original group of organisms.

40. Chapter Two
Darwin’s finches

41. Unity in Diversity

42. Chapter Two
Life is competitive—not everyone survives. (environmental pressures)

43. Chapter Two Thomas Malthus—population is limited by food supply.
Traits enhance survival
Competition for resources
The best adapted survive, and population is kept in check.

44. Chapter Two AND… over time, new species can emerge!
Common ancestors give rise to related species.

45. Chapter Two
So, Darwin new these survival and reproduction enhancing traits were being passed down from parents to offspring, but he did not know quite how…

46. Chapter Two Lamarckian inheritance of acquired characteristics.
New demand=new organ/modification
This change is then passed on to offspring

47. Chapter Two

48. Chapter Two

49. Chapter Two Gregor Mendel provides the how of natural selection.
Discrete physical unit
Blending inheritance (gemmules)

50. Chapter Two: Mendel Unit=gene Two subunits=alleles
Dominant (expressed) and recessive (hidden)
Ex. Tallness and shortness in pea plants (Larsen 2014:39)
Genes that determine these traits are located in reproductive cells!

51. Chapter Two: Mendel
Johannsen and others expand upon Mendel’s theory of inheritance (which forms the basis of modern genetics).
Johannsen labels allele pair “genotype” and physical appearance “phenotype”

52. Exercise
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53. Chapter Two
Mendel’s theory of inheritance triggers curiosity among biologists about origin of genes, variance, and change in characteristics over time.
Population genetics

54. Chapter Two Thomas Hung Morgan—fruit flies
Mutation: the only source of new genetic material!

55. Chapter Two
Gene flow: the transfer of genes between populations.

56. Chapter Two

57. Gene Flow Con’t

58. Gene Flow Sickle Cell Anemia as an example of gene flow in humans.
Gene flow decreases genetic difference between populations.

59. Chapter Two
Genetic drift: random change in the frequency of alleles (forms of a gene).
Acts more intensely on a small population, and can increase genetic difference between two genetically related but not interbreeding members of a population.

60. Genetic Drift Con’t

61. Chapter Two So, the four causes of evolution include:
1.) Natural Selection
2.) Mutation
3.) Gene Flow
4.) Genetic Drift

62. Chapter Two
Remember, all organisms are related through common descent, but those that share a more recent common ancestor are more closely related.