Modern Homo sapiens Contemporary Populations

Migration of Homo sapiens After peopling the Old World, others migrated to new worlds. H. sapiens migrated to the Near East by 90,000 BP East Asia by 50,000 BP Europe and Australia by 40,000 BP New World by 15,000-30,000 BP

After peopling the Old World, others migrated to new worlds.

H. sapiens migrated to the

Near East by 90,000 BP

East Asia by 50,000 BP

Europe and Australia by 40,000 BP

New World by 15,000-30,000 BP

Polytypic Traits When populations migrate They may become reproductively isolated The potential for speciation exists This is mitigated by gene flow, no matter whether we all came out of Africa whether we all evolved in different regions

When populations migrate

They may become reproductively isolated

The potential for speciation exists

This is mitigated by gene flow, no matter whether

we all came out of Africa

whether we all evolved in different regions

Culture and Race: Pop Quiz What is the race of each student? What is the cultural background of each student? Am I asking the right questions?

What is the race of each student?

What is the cultural background of each student?

Am I asking the right questions?

Culture and Race: The Answers The first student is Angela Corbett : An African American, Native Indian “Caucasian” (actually Irish), Hispanic The second student is Ethan Hernandez: A Latino and Caucasian The third student is Roxanne Cnudde : Of American Indian, Spanish, Mexican And Belgian “heritage.”

The first student is Angela Corbett :

An African American, Native Indian

“Caucasian” (actually Irish), Hispanic

The second student is Ethan Hernandez:

A Latino and Caucasian

The third student is Roxanne Cnudde :

Of American Indian, Spanish, Mexican

And Belgian “heritage.”

Defining Race What is race? Skin color? Hair texture? Race is Inherited genetically Polytypical outcome of speciation Too often confused with culture

What is race?

Skin color?

Hair texture?

Race is

Inherited genetically

Polytypical outcome of speciation

Too often confused with culture

Defining Culture Culture is Based on learned behavior Shared by a group Conveyed by symbolic behavior, principally language Patterned or Integrated Too often confused with race Chicanos: self-reference as la raza: “ Race” and “ethnicity” used interchangeably in that term

Culture is

Based on learned behavior

Shared by a group

Conveyed by symbolic behavior, principally language

Patterned or Integrated

Too often confused with race

Chicanos: self-reference as la raza:

“ Race” and “ethnicity” used interchangeably in that term

Race and Culture: Related but Different Capacity for culture is inherited through the genes Capacity for language Capacity for tool making and use Genes do not determine the Language we speak: English, French, Mandarin Tools we make and use: handaxes, pneumatic hammers or drills, computers East Indians are as competent English speakers or computer users as North Americans are How do we know? They’re taking our jobs!

Capacity for culture is inherited through the genes

Capacity for language

Capacity for tool making and use

Genes do not determine the

Language we speak: English, French, Mandarin

Tools we make and use: handaxes, pneumatic hammers or drills, computers

East Indians are as competent English speakers or computer users as North Americans are

How do we know? They’re taking our jobs!

Why the Confusion? Scientific versus Folk Taxonomy Scientific taxonomy: Race has no validity There is greater variation within groups than between groups

Scientific versus Folk Taxonomy

Scientific taxonomy:

Race has no validity

There is greater variation within groups than between groups

Folk Taxonomy Opinion polls: Caucasian, Negroid, Mongoloid Ignores other variants too long to list Ignores complexities of the following: Skin color: Shades throughout the spectrum Hair texture: Straight to curly to kinky Blood type: No correlation with other attributes

Opinion polls: Caucasian, Negroid, Mongoloid

Ignores other variants too long to list

Ignores complexities of the following:

Skin color: Shades throughout the spectrum

Hair texture: Straight to curly to kinky

Blood type: No correlation with other attributes

Clines and Discontinuous Traits Definition of Clinal Distribution (Clines) A geographic continuum In the variation of a particular trait What are these particular traits? Skin color (by melanin content, white to very dark brown) Body build (by weight and surface area) Discontinuous Variation : Traits with little or no variation Example: red hair in United Kingdom

Definition of Clinal Distribution (Clines)

A geographic continuum In the variation of a particular trait

What are these particular traits?

Skin color (by melanin content, white to very dark brown)

Body build (by weight and surface area)

Discontinuous Variation : Traits with little or no variation

Example: red hair in United Kingdom

What Can We Conclude About Race? I Race is a product of genes --microevolution (polytypic) Culture is the product of learning in a shared linguistic context Can we ignore race? As a purely biological concept, yes “ Race is unsupported by scientific evidence We cannot ignore biological variations, such as sickle cell anemia blacks Or Tay-Sachs disease among Eastern European Jews

Race is a product of

genes --microevolution (polytypic)

Culture is the product of learning in a shared linguistic context

Can we ignore race?

As a purely biological concept, yes

“ Race is unsupported by scientific evidence

We cannot ignore biological variations, such as sickle cell anemia blacks

Or Tay-Sachs disease among Eastern European Jews

What Can We Conclude about Race As a cultural construct, Visible differences are always addressed sociologically Folk taxonomies persist—including la raza A person I know is half-Armenian On a form asking race/ethnicity, she writes “Human” Lately, she has written “Person of Color, Medium Beige” How do I know all this? She’s my wife. (I’m person of no-color myself.)

As a cultural construct,

Visible differences are always addressed sociologically

Folk taxonomies persist—including la raza

A person I know is half-Armenian

On a form asking race/ethnicity, she writes “Human”

Lately, she has written “Person of Color, Medium Beige”

How do I know all this? She’s my wife. (I’m person of no-color myself.)

How did we become all one species? Skin color and hair texture are both products of several genes— polygenic --so we can expect variation We move around a lot Caribou and reindeer stayed put Over 10,000 years evolved into separate subspecies of Rangifer tarandus : reindeer in Eurasia, caribou in North America (see text, pp. 293-295) We’ve been around up to 130,000 years, maybe more We’re always in search for better resources for food, clothing, and shelter Transportation improvements also helped

Skin color and hair texture are both products of several genes— polygenic --so we can expect variation

We move around a lot

Caribou and reindeer stayed put

Over 10,000 years evolved into separate subspecies of Rangifer tarandus : reindeer in Eurasia, caribou in North America (see text, pp. 293-295)

We’ve been around up to 130,000 years, maybe more

We’re always in search for better resources for food, clothing, and shelter

Transportation improvements also helped

Adaptation: Skin Pigmentation Skin color may be adaptive: Gloger’s Rule : Within a species, more pigmented populations live near the Equator (map, upper left) Lighter populations live further away from the Equator Rationale: melanin serves as protection against ultraviolet rays of sun Applies to all mammals and even birds (sparrows, lower left)

Skin color may be adaptive:

Gloger’s Rule : Within a species, more pigmented populations live near the Equator (map, upper left)

Lighter populations live further away from the Equator

Rationale: melanin serves as protection against ultraviolet rays of sun

Applies to all mammals and even birds (sparrows, lower left)

Adaptation: Weight Bergmann’s Rule : Within same species, average (mean) weight of individuals in a population increases as the average environmental temperature decreases Rationale: More storage needed for energy required to survive in cold climates See distribution of house sparrows on map (above left) Compare white tailed deer in Michigan and Nicaragua (below)

Bergmann’s Rule : Within same species, average (mean) weight of individuals in a population

increases as the average environmental temperature decreases

Rationale:

More storage needed for energy required to survive in cold climates

See distribution of house sparrows on map (above left)

Compare white tailed deer in Michigan and Nicaragua (below)

Adaptation: Surface Area Allen’s Rule: Within same species, the relative size of protruding parts of the body (nose, ears), and the relative length of arms and legs increase, as the average environmental temperature increases Rationale: The greater the surface area, the greater the heat loss (Masai warriors, western Keny, upper left) The lesser the surface area, the lesser the heat loss (Athabaskan peoples, near arctic, lower left)

Allen’s Rule: Within same species, the relative size of protruding parts of the body (nose, ears), and the relative length of arms and legs increase, as the average environmental temperature increases

Rationale:

The greater the surface area, the greater the heat loss (Masai warriors, western Keny, upper left)

The lesser the surface area, the lesser the heat loss (Athabaskan peoples, near arctic, lower left)

Testing the “Rules” Some populations do conform to the “rules” Lighter skin is usually found in the north (Gloger’s Rule) Greater fat is found among Inuit, other circumpolar peoples (Bergmann’s Rule) Limbs tend to be shorter among northern peoples (Allen’s Rule) Darker skin is found among equatorial peoples Thinner and long-limbed populations are also found among equatorial populations

Some populations do conform to the “rules”

Lighter skin is usually found in the north (Gloger’s Rule)

Greater fat is found among Inuit, other circumpolar peoples (Bergmann’s Rule)

Limbs tend to be shorter among northern peoples (Allen’s Rule)

Darker skin is found among equatorial peoples

Thinner and long-limbed populations are also found among equatorial populations

Exceptions: Biological Features and Why Culture Matters Dark skinned populations also found in the north (Inuit, East Asians), contrary to Gloger’s Rule Northern Europeans (Scandinavian) are long-limbed and thin, contrary to Allen’s Rule Cultural adaptations are more important than biological ones Culture separates us from direct pressures of natural selection Question: How do tropical animals survive in extremely cold climates—like the Inuit (Eskimo)?

Dark skinned populations also found in the north (Inuit, East Asians), contrary to Gloger’s Rule

Northern Europeans (Scandinavian) are long-limbed and thin, contrary to Allen’s Rule

Cultural adaptations are more important than biological ones

Culture separates us from direct pressures of natural selection

Question: How do tropical animals survive in extremely cold climates—like the Inuit (Eskimo)?

Cultural Adaptations: The Igloo How Inuit adapt to the north; the igloo, for one Basic Design (see left, and p. 262 of Park text) The entrance tunnel keeps out snow and wind Entrance chamber face south or east, facing away from prevailing winds and maximizing use of sunlight Removable door adds to the insulation Ice window and snow block to reflect light from window Sleeping platform located where heat rises Geodesic dome minimizes wind resistance

How Inuit adapt to the north; the igloo, for one

Basic Design (see left, and p. 262 of Park text)

The entrance tunnel keeps out snow and wind

Entrance chamber face south or east, facing away from prevailing winds and maximizing use of sunlight

Removable door adds to the insulation

Ice window and snow block to reflect light from window

Sleeping platform located where heat rises

Geodesic dome minimizes wind resistance

Cultural Adaptations and Evolution Subsistence strategies is another cultural adaptation Hunting and gathering involves heavy dependence on nature (!Kung hunters, upper left) Horticulture: affords greater control of food sources, encourages settlement Agriculture: leads to complex societies Agriculture, such as this subak irrigation system, allows an unprecedented productvity This Balinese system kept the land producing for more than 1,000 years (lower left)

Subsistence strategies is another cultural adaptation

Hunting and gathering involves heavy dependence on nature (!Kung hunters, upper left)

Horticulture: affords greater control of food sources, encourages settlement

Agriculture: leads to complex societies

Agriculture, such as this subak irrigation system, allows an unprecedented productvity

This Balinese system kept the land producing for more than 1,000 years (lower left)

Racism: A Cultural Phenomenon Folk taxonomy Misinterpretation of biological attributes that involve an unwarranted connection between biological attributes with culture Example: Eugenics, or breeding a “superior race” that Francis Galton, a cousin of Darwin, founded Example: “Intelligence”: Abilities come in several forms, and there are several kinds of intelligence. The threefold category of “Negroid,” “Caucasoid,” and “Mongoloid” has long been refuted, yet this term is still used in police work and even among some sociologists

Folk taxonomy

Misinterpretation of biological attributes that involve an

unwarranted connection between biological attributes with culture

Example: Eugenics, or breeding a “superior race” that Francis Galton, a cousin of Darwin, founded

Example: “Intelligence”: Abilities come in several forms, and there are several kinds of intelligence.

The threefold category of “Negroid,” “Caucasoid,” and “Mongoloid” has long been refuted, yet this term is still used in police work and even among some sociologists

Measuring Population Stability: Hardy-Weinberg Equilibrium To understand change, we need to examine factors of stability. Hardy-Weinberg Equilibrium is a contrary-to-fact formula of population stability This formula shows how genotypic frequencies predict static populations with no evolutionary change In othr words, mating is random—no partner preference—no mutation occurs, no migration or gene flow, and no genetic drift This formula is named after Godfrey Hardy, a mathematician and Wilhelm Weinberg, a physicist, who developed it

To understand change, we need to examine factors of stability.

Hardy-Weinberg Equilibrium is a contrary-to-fact formula of population stability

This formula shows how genotypic frequencies predict static populations with no evolutionary change

In othr words, mating is random—no partner preference—no mutation occurs, no migration or gene flow, and no genetic drift

This formula is named after Godfrey Hardy, a mathematician and Wilhelm Weinberg, a physicist, who developed it

Seven Conditions of the Hardy-Weinberg Equilibrium These are the seven conditions, none of which exists in the real world 1 . mutation is not occurring 2. natural selection is not occurring 3. the population is infinitely large 4. all members of the population breed 5. all mating is totally random 6. everyone produces the same number of offspring 7. there is no migration in or out of the population

These are the seven conditions, none of which exists in the real world

1 . mutation is not occurring

2. natural selection is not occurring

3. the population is infinitely large

4. all members of the population breed

5. all mating is totally random

6. everyone produces the same number of offspring

7. there is no migration in or out of the population

Sickle Cell Anemia as Example, I Refresher on Sickle Cell Anemia A – hemoglobin free of sickle cells S – hemoglobin with sickle cells AS – sickle cell/non-sickle cell heterozygotes

Refresher on Sickle Cell Anemia

A – hemoglobin free of sickle cells

S – hemoglobin with sickle cells

AS – sickle cell/non-sickle cell heterozygotes

Sickle Cell Anemia as Example, II Conditions of homozygotes/ heterozygotes AA – Normal but subject to malaria SS – Subject to sickle cell anemia AS – Subject to neither sickle cell anemia nor to malaria

Conditions of homozygotes/ heterozygotes

AA – Normal but subject to malaria

SS – Subject to sickle cell anemia

AS – Subject to neither sickle cell anemia nor to malaria

Hardy-Weinberg Equilibrium: 2 X 2 Table A Null Hypothesis: the assumption that nothing is happening Basic Table (A-normal; S-sickle cell anemia) Genotype Product of Frequencies AA p X p = p2 AS p X q = pq = 2pq SA q X p = qp SS q X q = q2

A Null Hypothesis: the assumption that nothing is happening

Basic Table (A-normal; S-sickle cell anemia)

Genotype Product of Frequencies

AA p X p = p2

AS p X q = pq

= 2pq

SA q X p = qp

SS q X q = q2

Hardy-Weinberg Equilibrium: The Formula p2 + 2pq + q2 = 1 (100%) The frequencies are percentages The percentages can be any proportion This predicts that Through the generations The percentages of traits remain the same

p2 + 2pq + q2 = 1 (100%)

The frequencies are percentages

The percentages can be any proportion

This predicts that

Through the generations

The percentages of traits remain the same

Hardy-Weinberg Equilibrium: Indications of Evolutionary Change If the percentages change, some evolutionary change has occurred Mutation Nonrandom mating Migration (gene flow) Change by chance (genetic drift—if a frequency is very low)

If the percentages change, some evolutionary change has occurred

Mutation

Nonrandom mating

Migration (gene flow)

Change by chance (genetic drift—if a frequency is very low)

Use of the Hardy-Weinberg Equilibrium Presence of diseases, such as AIDS/HIV Impact on population Relations with disease-causing species, such as the green monkey Genetic diseases impact Demographic changes, such as migration (blood types have been used)

Presence of diseases, such as AIDS/HIV

Impact on population

Relations with disease-causing species, such as the green monkey

Genetic diseases impact

Demographic changes, such as migration (blood types have been used)

Conclusion What we have covered: The fallacy of race The confusion between race and culture Explanations of human physical variations The Hardy-Weinberg Equilibrium to anticipate the changes that do take place.

What we have covered:

The fallacy of race

The confusion between race and culture

Explanations of human physical variations

The Hardy-Weinberg Equilibrium to anticipate the changes that do take place.