1. Human Evolution,
Human Populations,
And Race

2. Orang
Gorilla
Human
Chimp
Bonobo
Problem:
A proverbial Martian anthropologist is given the task of classifying the great apes. For simplicity these are the human, chimpanzee, orangutan, and gorilla. Which is the “odd species out?”
Figure from:

3. Genetically, it is the orang!

4. Great Ape Evolutionary Timeline15 12 9 6 3
Million Years Ago
Borneo
Sumatra
Chimp
Homo Sapiens
Eastern
Western
Gorilla
Common
Bonobo
Orangutan

5. Lesson: Genetically, orangs are the “odd ape out,” then gorillas
Hence, humans are genetically more similar to a chimpanzee than a chimpanzee is to a gorilla and a chimp is to an orang!
Do not judge genetic distance using external morphology!

6. Adaptation to savannah ecology

7. Human Ancestors
From:

8. Fossil hominid skulls: (A) Pan troglodytes chimpanzee, modern (B) Australopithecus africanus, STS 5, 2.6 Million years (C) Australopithecus africanus,
STS 71, 2.5 Million years (D) Homo habilis, KNM -ER 1813, 1.9 million years (E) Homo habilis, OH24, 1.8 Mi A (F) Homo rudolfensis, KNM-ER 1470,
1.8 Mi A (G) Homo erectus, Dmanisi cranium D2700, 1.75 Mil Year (H) Homo ergaster (early H. erectus), KNM-ER 3733,
1.75 Mi A (I) Homo heidelbergensis, "Rhodesia man," to years * (J) Homo sapiens neanderthalensis, La Ferrassie 1,
70,000 years (K) Homo sapiens neanderthalensis, La Chappelle-aux-Saints, 60,000 years (L) Homo sapiens neanderthalensis, Le Moustier,
45,000 years (M) Homo sapiens sapiens, Cro-Magnon I, 30,000 years (N) Homo sapiens sapiens, modern

9. 1 HOMO HABILIS ~ NICKNAME: Handyman LIVED: 2. 4 to 1
1 HOMO HABILIS ~ NICKNAME: Handyman LIVED: 2.4 to 1.6 million years ago HABITAT: Tropical Africa DIET: Omnivorous – nuts, seeds, tubers, fruits, some meat 2 HOMO SAPIEN ~ NICKNAME: Human LIVED: 200,000 years ago to present HABITAT: All DIET: Omnivorous - meat, vegetables, tubers, nuts, pizza, sushi 3 HOMO FLORESIENSIS ~ NICKNAME: Hobbit LIVED: 95,000 to 13,000 years ago HABITAT: Flores, Indonesia (tropical) DIET: Omnivorous - meat included pygmy stegodon, giant rat 4 HOMO ERECTUS ~ NICKNAME: Erectus LIVED: 1.8 million years to 100,000 years ago HABITAT: Tropical to temperate - Africa, Asia, Europe DIET: Omnivorous - meat, tubers, fruits, nuts 5 PARANTHROPUS BOISEI ~ NICKNAME: Nutcracker man LIVED: 2.3 to 1.4 million years ago HABITAT: Tropical Africa DIET: Omnivorous - nuts, seeds, leaves, tubers, fruits, maybe some meat 6 HOMO HEIDELBERGENSIS ~ NICKNAME: Goliath LIVED: 700,000 to 300,000 years ago HABITAT: Temperate and tropical, Africa and Europe DIET: Omnivorous - meat, vegetables, tubers, nuts 7 HOMO NEANDERTHALENSIS ~ NICKNAME: Neanderthal LIVED: 250,000 to 30,000 years ago HABITAT: Europe and Western Asia DIET: Relied heavily on meat, such as bison, deer and musk ox

10. Human Migrations (Old World)
From:

11. Note the recent dates of some migrations, particularly in Europe
Some migration routes remain under debate. For example, there is still some uncertainty regarding the migration routes used to populate the Americas. Genomic data are limited in their resolution to determine paths of migration because further population movements, subsequent to the initial migrations, may obscure the geographic patterns that can be discerned from the genomic data. Proposed routes of migration that remain controversial are indicated by dashed lines. CA, Central Anatolia; FC, Fertile Crescent; IP, Iberian Peninsula; PCS, Pontic–Caspian steppe.
Note the recent dates of some migrations, particularly in Europe
From Nielsen et al., (2017) Nature, 541, p. 306

12. Hominid Evolutionary Timeline: Key Points
African origin
Adaptation to the savannah
Many tries to get hominid species “right”
We are the only hominid species left
We are a very new species (only c. 150,000 – 200,000 years old)
Migrated and established cultures in every continent except Antarctica

13. Race: Definitions Strict Categories Morphological Features
Traditional Biological Classification (subspecies, populations)
Self-nominated Categories
Social Construct

14. RACE: Definitions Biological Social Morphological Self-Nomination
Social Construct
Subspecies
Population

15. Race: Strict Categories
Sharp boundaries between groups
Akin to separating a collection of tools into hammers, saws, etc.
No one from Blumenbach (1779) onwards believes this
“ … if races have to be 'discrete units,' then there are no races” Theodosius Dobzhansky

16. Race: External Morphology
External physical appearance defines race
Skin color, hair color/texture, facial appearance

19. Mbuti Negrito (Malaya)
2009/10/why-pygmies- are-small/
"Malaya 1905" by Michaela Macan - Unknown. Licensed under Public Domain via Commons - .wikimedia.org/wiki/File: Malaya_1905.jpg#/media/ File:Malaya_1905.jpg
Negrito (Malaya)

20. Skin Color: Adaptation to equitorial environment

21. Race: Biological: Subspecies
No category called “race” in the International Commission on Zoological Nomenclature (ICZN)
Lowest category is “subspecies” which the ICZN does not define
Many definitions, most include aspects of geographical isolation, different ecologies, and much breeding within but little between subspecies
Problem: Any biological definition of subspecies or race must apply to all life forms—human, oak trees, slime mold, etc.
Example: Tigers

22. Tiger Subspecies
From:

23. Tiger Subspecies By Robyn Barfoot,
From

24. Human Subspecies?
PRO:
Some human groups separated for 10k years or more. E.g., Amerinds from rest for c. 15k years and Australians/New Guinea from rest for c. 30k
Wright (1978): casual observers can easily classify pictures of folks from Japan, Nigeria, England, etc.

25. Human Subspecies?
CON:
Many humans groups differ more dimensionally = cline
We are a new species and have not had sufficient time to diverge into subspecies.
Much more genetic variability within a group than between groups.
Some (e.g., Templeton) argue that human groups are genetically too similar to be called “subspecies.” There is more genetic diversity in some chimp troops than there is in the entire human species!
Definitely are not subspecies as tigers are.

26. Biological: Race: Population
Population = a group of individuals with a characteristic set of allele frequencies that has largely mated within itself for a long time.
Concept is relative, i.e., a person may belong to the European population, the Italian population and the Sicilian population at the same time.
Hence, hierarchical
Hence, no such thing as the “correct number of races”
Race = ? A high set in the hierarchy

27. From: http://anthro.palomar.edu/ vary/vary_2.htm

28. New world genetic dendrogram; colors = language groups
From: Wang et al. (2007)
PLoS Genetics, 3:e185

29. Tishkoff & Kidd (2004). Nature Genetics Supplement, 36, S21-S27

30. From Shriner et al. (2014) Nature
Africa
Indo- European
Asia

31. Human populations blend: Genetically, you look like your neighbors
Cavalli-Sforza et al. (1994) The history and geography of human genes.

32. Height is dimensional. Therefore, is “tall” and “short” invalid?
Clines:
Is red different than green?
Or magenta from blue?
Height is dimensional. Therefore, is “tall” and “short” invalid?
From:

33. CAUTION: Polygenic scores based on one group may not extrapolate to other groups
AFR: African
AMR: African & Hispanic American
EAS: East Asian
EUR: European
SAS: South East Asia (India)
From Martin et al. (2018) AJHG, 100:

34. Race: Self-nominated
Box or boxes that a person checks on a research form, census form, application, etc.
Difference between “race” and “ethnicity” can differ from form to form

35. Race: Self-nominated Tang et al. (2005) AMHG, 76:268-275
Large study (Family Blood Pressure Program)
Self-nominated race/ethnicity of 4 categories: African American, Asian American, Hispanic, white
Took 4 clusters form an analysis of 326 short tandem repeat polymorphisms; clusters independent of self-nominated categories.

36. Race: Self-nominated Tang et al. (2005) AMHG, 76:268-275
“Of 3,636 subjects of varying race/ethnicity, only 5 (0.14%) showed genetic cluster membership different from their self-identified race/ethnicity.” p. 268

37. Race: Self-nominated
Replicated by Guo et al (21xx) in two other independent samples
Largest error rates = 7 - 8%
Most errors ~ 1 – 3%

38. Race: Social Construct
Etiological, not a definition
Wikipedia (from 6 different pubs, 2015): “Race, as a social construct, is a group of people who share similar and distinct physical characteristics.”

39. Race: Social Construct
Social construct versus genetic?
Are the two mutually exclusive?
What causes the “physical characteristics?
“Versus” is stupid. Akin to asking if water is hydrogen or oxygen.

40. Similarity and Diversity
Human Genome:
Similarity and Diversity
Whole Human Genome
Just Differences

41. Human Genetic Variability
Within group = %; between group = %
Therefore, an asteroid stuck earth and killed every human except those in Australia, the survivors would have % of the genetic variability that exists today.

42. Why Do We Look So Different?
“… [T]he genes that show the greatest difference in allele frequency between continental groups (indigenous Africans, Europeans, Americans and Australians) are enriched for associations with visible traits such as skin, hair and eye pigmentation. An interesting consequence is that the geographic groups are more different from each other in terms of pigmentation than they are, on average, at the level of the genome.”
Nielsen et al., (2017), Nature, 541, p. 307