- Consider the concept of race in our society. In a post of at least 250 words, answer the following questions:
- Are racial categories biologically or culturally constructed?
- What does it mean to say that genes are “probabilistic rather than deterministic?
- Why is it false to say that one racial group is smarter, stronger, or better athletes than other racial groups?
- Why is ethnicity more inclusive categorization method?
Module 5
Race and Human
Variation
1
The Concept of Race
Humans can be classified into 1 of 5 categories – impossible to do; not the same in all countries
Members of one race share a set of biological characteristics that are not shared by members of other races
Long-term populations may have some alleles in common but more genetic variation within races than between them
Race primarily based on skin color (less than 0.01%)
“Races” are not biological, instead social construct
Has lead to cultural stereotypes about disease, athletic ability, and other unfair categorizations of human behavior
the concept of race has historically been a tool that some people use to subjugate others
2
Today’s “Race” Definitions for US Census
American Indian or Alaska Native
Asian
Black or African American
Native Hawaiian or Other Pacific Islander
White
Categorizes have changed over the years, in the 1850s 3 catagories Black, white, and Mulatio
3
Latinos and Arabic
Latinos viewed as ethnicity not race
Possible MENA (Middle Eastern/North African)in future
What “race” is Tiger Woods?
Self → CABLINASIAN
¼ African American
¼ Thai
¼ Chinese
⅛ Native American
⅛ White European
U.S. = Black
Brazil = White
Genealogy = Asian
5
Age of Exploration 15th Century
Europeans considered “new” people lesser beings
François Bernier (1684) first to divide humans into groups (4)
Europeans, Africans, Asians, Lapps
6
2018 = 334 years Skin color, hair texture
Number of “Races”
Linnaeus (1735) – 4 Races
Europeans
Africans
Asians
American Indians
Linnaeus (1758) – 5 Races
Asians
“Angry; regulated by customs”
“Crafty and sluggish; ruled by caprice”
“Melancholy, cautious; ruled by opinion”
“Muscular, inventive; governed
by laws”
Blumenbach (1779) – 5 Races
Caucasian
Ethiopian
Malayan
American
Mongolian
Linnaeus (1735) – 4
(White, Brown, Black, Red)
Added temperaments in 10th edition (1758)
Americanus: reddish, merry, free; regulated by customs”
Blacks “crafty, lazy, and careless”
Indians are “excitable, impulsive, and restless”
Asians are “serious, cautious, and suspicious”
Changed Asians from brown to yellow
Added wastebasket category (Monstrous)
5 Races
White (Caucasian)
Yellow (Mongolian)
Brown (Malayan)
Black (Ethiopians)
Red (American)
7
“Race” in the 19th Century
Used interchangeably with people, nation, etc.
Racial differences and rankings are “science”
Measurable biological differences
Based on characteristics (such as skin color, head shape, nose, etc.) considered inherited and permanent, traits
8
8
Smedley p. 38 – 40
Degenerative Theory
Whites superior as they were “civilized” – also making classifications
Believed first humans were ”white”
Other races degenerative forms of Europeans
Evolutionary Theory
Evolutionary-speaking all humans are of African ancestry
Populations spread out and adapted to their environment
There are no degenerative forms of humans
Changes in Skin Color
Originally light color skin covered by dark hair, similar to chimps
After bipedalism, hominins loose hair, and over time, adapt a darker color
Has homo sapiens spread into different environments skin color adapts again
Cheddar Man 9,100 years ago
Somerset, England
First permanent inhabitants of the island
20s male
Great Britain’s oldest complete skeleton
9100/20 = more than 450 generations most people can trace back 10-25 generations
Last 200 years (10 generations) height has increased 4 inches
Boaty mcboatface
12
Genome Sequencing
Genome extracted in 2018 suggests he had blue eyes, dark skin, dark curly hair and lactose intolerance
~10% of modern Britons share Mesolithic European ancestry
Remainder comes from later immigrants
he DNA of Adrian Targett, who was 42 years old when that discovery was made, was found to match that belonging to Cheddar Man. According to science, this genetic fingerprint is said to have been passed down from mother to child. In other words, Targett and Cheddar Man both share a common maternal ancestral. It may be added that Targett was not the only one from his family to have not moved away from his ancestral land. It was reported that there were 46 individuals in his extended family, and most of them had remained in the Somerset area.
13
Gloger’s Rule
Adaptation to tropical environments – more pigment then species in cooler/arid areas
Found in a number of different mammals and birds
14
Other Rules of Adaptation
Bergmann’s: the size of the body relative to the climate
Allen’s: the size of protruding body parts (ears, tails, bills, fingers, toes, and limbs) relative to climate
Thomson’s: the size and shape of the nose
When organisms are more compact, they tend to conserve heat (due to a high mass:surface area ratio). When organisms are more linear, they tend to lose more heat (due to a low mass:surface area ratio).
This has been applied to humans. The idea is that populations toward the pole tend to be shorter and have shorter limbs than do people on the equator.
For example, the Inuit people of Canada (pictured above) tend to be shorter than the Maasai people of Kenya
Thomson's Nose Rule, which states that ethnic groups originating in cold, arid climates tend to have longer and thinner noses, while the noses of those from warm, humid climates tend to be shorter and thicker. [1] The longer nose is an adaptation that heats and moistens inhaled air in higher latitudes.
15
Bergman’s & Allen’s Rules
Skin Color
In tropics, high levels of UV radiation
Melanin (dark skin) protects from radiation
Reduces skin cancers and folic acid deficiency
In high latitudes, low levels of UV radiation
Reduced melanin permits UV radiation to penetrate skin facilitate vitamin D synthesis
17
Vitamin D Deficiency
Vitamin D is necessary for proper growth of bones and teeth
Deficiency during development can cause Rickets
Defect in growing bone making them weak, brittle, and deformed
Leg bone deformity impairs locomotion
Pelvic distortion can make childbearing dangerous–potentially killing mother and baby
18
Pelvic Deformation
19
Sickle Cell Anemia
Genetic disease thought to be “African” disease
Inherited recessive
When stressed for oxygen, red blood cells freeze up and sickle
20
As a result of sickling and the premature aging of red blood cells from sickling, there are fewer than normal red blood cells, the general condition referred to as anemia
There is an increased risk of severe infections, especially bacterial infections–such as sepsis (a blood stream infection), meningitis, and pneumonia, especially in early childhood
The risk of infection is increased because the spleen does not function normally
Children with sickle cell anemia experience slowed growth and delayed maturation
Repeated, painful episodes, caused by blockages of the circulatory system
Frequently seen as swelling of extremities
There is a progressive degeneration of organs from impaired circulation
Without medical care this is frequently lethal at an early age!
Malaria and Sickle Cell
Genetic disease occurs in populations that have a history of malaria
Sickle cell reaches significant frequencies in Greece, but is absent among the San of South Africa
21
Malaria is a mosquito-borne infectious disease affecting humans and other animals caused by parasitic protozoans (a group of single-celled microorganisms) belonging to the Plasmodium type.[2] Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches.[1] In severe cases it can cause yellow skin, seizures, coma, or death.[1] Symptoms usually begin ten to fifteen days after being bitten.[2] If not properly treated, people may have recurrences of the disease months later.[2] In those who have recently survived an infection, reinfection usually causes milder symptoms.[1] This partial resistance disappears over months to years if the person has no continuing exposure to malaria
Malaria and Sickle Cell
22
“Race” and Athletics
Genetics influence individual ability in athletic events
Has nothing to do with race
Performance influenced by cultural factors: perceptions, availability of resources, coaching, training
23
Derek drounin 2016 winner; Cuban 1993 record holder
Simone Ashley Manuel (born August 2, 1996) is an American competition swimmer specializing in sprint freestyle. At the 2016 Rio Olympics, she won two gold and two silver medals: gold in the 100-meter freestyle and the 4×100-meter medley, and silver in the 50-meter freestyle and the 4×100-meter freestyle relay. In winning the 100-meter freestyle, a tie with Penny Oleksiak of Canada, Manuel became the first African-American woman to win an individual Olympic gold in swimming and set an Olympic record and an American record.
Traits are not distributed in neat regional packages
Skin color, hair form, body build, and intelligence do not “track” together
These traits are discordant and are not all hard-wired by genetics
Race would be biologically useful traits were concordant
If hair and nose and skin color always tracked together
Melansia
Variety is the Spice of Human Life…
All Humans are members of one species
Race is a social construct not a biological construct
A wide variety of physical differences characterize individuals of our species