And Race 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 ID: 918111
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Slide1
Human Evolution,
Human Populations,
And Race
Slide2Problem:
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?”
Orang
Gorilla
Human
Chimp
Bonobo
Figure from: http://
boscoh.com
/
longform
/
humanevolution
/
Slide3Genetically, it is the orang!
Slide4Great Ape Evolutionary Timeline
15
12
9
6
3
0
Million Years Ago
Borneo
Sumatra
Chimp
Homo
Sapiens
Eastern
Western
Gorilla
Common
Bonobo
Orangutan
Slide5Genetically, 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!
Lesson:
Slide6Adaptation to savannah ecology
http://www.stratics.com/content/portals/de/content/media/gallery/de-90103pr_roughsav.jpg
Slide7Human Ancestors
From: https://
forums.oneplus.net
/threads/evolution-of-human-face-in-past-6-million-years.401866/
Slide8Fossil 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," 300.000 to 125.000 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
http://
darwiniana.org
/
hominid.htm
Slide9http://www.theage.com.au/news/Science/Skeletons-in-the-cupboard/2005/03/18/1111086008084.html
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
Slide10From Henn et al. (2012) PNAS
Slide11Human Migrations (Old World)
From: http://
www.handprint.com
/LS/ANC/disp.html
Slide12Some 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.
From Nielsen et al., (2017) Nature, 541, p. 306
Note the recent dates of some migrations, particularly in Europe
Slide13Hominid Evolutionary Timeline:
Key Points
African origin
Adaptation to the savannahMany tries to get hominid species “right”
We are the only hominid species leftWe are a very new species (only c.150,000 – 200,000 years old)Migrated and established cultures in every
continent except Antarctica
Slide14Race: Definitions
Strict Categories
Morphological Features
Traditional Biological Classification (subspecies,
populations)Self-nominated CategoriesSocial Construct
Slide15Subspecies
Population
Morphological
Self-Nomination
Social Construct
RACE: Definitions
Social
Biological
Slide16Race: 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
Slide17Race
: External Morphology
External physical appearance defines race
Skin color, hair color/texture, facialappearance
Slide18Slide19Slide20"Malaya 1905" by Michaela
Macan
- Unknown. Licensed under Public Domain via
Commons - https://commons.wikimedia.org/wiki/File:Malaya_1905.jpg#/media/File:Malaya_1905.jpg
http://www.wired.com/2009/10/why-pygmies-
are-small/
Mbuti
Negrito(Malaya)
Slide21http://anthro.palomar.edu/vary/vary_3.htm
Skin Color:
Adaptation to equitorial environment
Slide22Race: 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 geographicalisolation, different ecologies, and much breeding within but little between subspeciesProblem: Any biological definition of subspecies orrace must apply to
all life forms—human, oak trees, slime mold, etc.
Example: Tigers
Slide23Tiger Subspecies
From: http://
www.pbs.org
/wnet/nature/broken-tail-a-tigers-last-journey-tigers-at-the-tipping-point/6387/
Slide24Tiger Subspecies
By Robyn Barfoot,
From http://
www.talesofthetiger.com/uncategorized/quick-comparison-of-tiger-subspecies/
Slide25Human Subspecies?
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.
PRO:
Slide26Human Subspecies?
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.
CON:
Slide27Biological: 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 tothe European population, the Italian populationand 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
Slide28From: http://
anthro.palomar.edu
/vary/vary_2.htm
Slide29New world genetic
dendrogram
;colors = language groups
From: Wang et al. (2007)PLoS
Genetics, 3:e185
Slide30Tishkoff & Kidd (2004). Nature Genetics Supplement, 36, S21-S27
Slide31From Shriner et al. (2014) Nature
Africa
Indo-
European
Asia
Slide32Cavalli
-Sforza et al. (1994) The history and geography of human genes.
Human populations blend:
Genetically, you look like your neighbors
Slide33From: http://
shapeof.com
/archives/2010/07/making_a_color_wheel_in_core_image.html
Clines:
Is red different than green?Or magenta from blue?
Height is dimensional. Therefore, is“tall” and “short” invalid?
Slide34CAUTION: Polygenic scores based on one group
may not extrapolate to other groups
AFR: African
AMR: African & Hispanic American
EAS: East AsianEUR: EuropeanSAS: South East Asia (India)
From Martin et al. (2018) AJHG, 100: 635-649
Slide35Race: Self-nominated
Box or boxes that a person checks on a research
form, census form, application, etc.
Difference between “race” and “ethnicity” candiffer from form to form
Slide36Tang 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 tandemrepeat polymorphisms; clusters independent of self-nominated categories.Race: Self-nominated
Slide37“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
Tang et al. (2005) AMHG, 76:268-275
Race: Self-nominated
Slide38Race: Self-nominated
Replicated by
Guo et al (21xx)in two other independent samples
Largest error rates = 7 - 8%
Most errors ~ 1 – 3%
Slide39Race: 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.”
Slide40Race: Social Construct
Social construct versus genetic?
Are the two mutually exclusive?
What causes the “physical characteristics?
“Versus” is stupid. Akin to asking if wateris hydrogen or oxygen.
Slide41Whole Human Genome
Just Differences
Human Genome:
Similarity and Diversity
Slide42Human Genetic Variability
Within group = 85 - 95%; between group = 5 - 15%
Therefore, an asteroid stuck earth and killed
every human except those in Australia,the survivors would have 85 - 95% of the genetic
variability that exists today.
Slide43This is what human genetic variation looks like:
Black line = Genetic variation for all humans
Blue line = Genetic variation BETWEEN populations
Red line = Genetic variation WITHIN populations
Notice how similar the black (total) and red (within) lines are
Slide44Why 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