Lecture 11

1350 B.C.

Ancient Egyptians classified humans based on skin color

Linnaeus 1738

Saw diversity is plants & animals

- classified humans into similar categories

Linnaeus 4 classified groups based on geography

H. Sapiens Americanus

H. Sapiens Asiaticus

H. Sapiens Africanus

H. Sapiens Europeaus

H. Sapiens Americanus

Native American males were red, had black hair & sparse beards, were stubborn;prone to anger; “free” & were governed by tradition. Inferior & uncivilized, compared to Europeans (like Linnaeus).

H. Sapiens Asiaticus

Male Aisan (yellowish, melancholy, endowed with black hair and brown eyes severe, conceited and stingy).He puts on loose clothing He is governed by opinion

H. Sapiens africanus

male of subset, recognized by skin tone, face structure, curly hair, cunning, passive, inattentive, ruled by impulse.

H. Sapiens Europeaus

changeable, clever, and inventive. He wears tight clothing, He is governed by laws”

Blumenbach 1775

Instead of skin color he related skull shape to racial classification.

- he placed a skull between his feet and gazed down onto it.

Blumenbach method of evaluation he divided humans into 5 racials groups:

Caucasian

- Mongolian

- Ethiopian

- American

- Malayan

Caucasians physical Indicators

Fairness” & relatively high brows of “Caucasians” were physical indicators of higher intelligence & more generous spirit.

Mondgolians physical indicators

Epicanthis folds around eyes of “Mondgolians” and slightly sallow outer epidermal layer indicated their supposedl crafty, literal

Ethiopians physical indicators

dark skin & relatively sloping craniums of “ethiopians” were taken as wholesale proof of a closer genetic proximity to the non human primates.

Biological Determinism

attrivtues such as intelligence, values, morals and even economic & social differences were determined by biological/genetic factors.

Retzius 1842

19th and 20th century people were trying to classify humans & determine racial types.

What did Anders Retzius, Swedish Anatomist develop?

cephalic index which descrivbes the head shape to categorie people into racial groups.

method called craniometry

physical measurements of the skull

Cehphalic index was derived by

dividing the masimun breadth of the head by the maximum length & multiplying it by 100.

Retzius 3 different head types

Dolichocephalic: index less than 75- long narrow heads

- Brachycephalic: index over 80- broad heads

- Mesocephalic: index between 75 and 80 between narrow and broad

Dolichocephalic

Index less than 75- long narrow heads

Brachycephalic

index over 80- broad heads

Mesocephalic

index between 75 and 80 between narrow and broad

Northern Eurpoeans tended to be…

Doliocephalic while southern Europeans were Bracycephalic

Eugenics

race improvement

Francis Galton

held responsible to the beginning of eugenics

- his concepts became popular in the United States & Europe banning inter-racial marriage in

Race has been used to define…

groups through distribution whch are usually associated with phenotypic variation.

Ethnicity

Only to shared culture

Polytypic Species

Species that is composed of local population that differ with regard to expression of one or more traits.

Gene Flow

Mixing of genes between populations

Discordant

Traits get all mixed up

Mono genetic or discrete traits…

Phenotypic expressions grouped into clearly defined categories.

Polygenic Traits

Traits influenced by genes at 2> loci on a chromosome, with each allele/locus making a contribution.

Polygenetic traits are influenced by non - genetic factors like…

Climate and Diet

Skin color is distributed according to…

Solar Radiation

UV radiation & sunlight gradually decrease as you go north…

this results in darkest skin occurring at equator

Melanocytes

produce melanin, the igment which gives skin its color

Ultra violet light stimulated activity of the melanocytes to produce melanin so both…

Genetics & environment play a role

Rickets

Can cause bowing of the leg bones, or narrowing of pelvis.

Less sunlight the…

Harder for darker skinned people to synthesize enough vitamin d.