Anthro: FINAL EXAM

Adaptation

Adaptation

A process in which a genetic based trait increases in frequencies due to it being beneficial. it allows an individual to survive and reproductively successfully. This advantage is connected to a specific environment, which means if the environment changes, so does the advantage (adaptation)

Traits that result from these genetic changes

Due to our ancestors we can exhibit these adaptations even if we don’t live in the area that adaptation came from. (Due to alleles (multi generational changes) passing from ancestors to generations)

Developmental acclimatization

Changes in organ or body structure during the growth of an organism (Due to stress). Usually permanent changes

Physiological acclimatization

Physiological change that occurs over days or months (Response to stress). Usually temporary changes

Acclimatization

Long term changes that occur within one’s lifetime in response to environmental stress

Acclimation

Short-term physiological responses to immediate environmental stress, aiding in adapting quickly to changing conditions.

Homeostasis

Maintenance of metabolic equilibrium in the body, regulating factors like body temperature and fluid composition for optimal function.

Cold Responses (Acclimation)

• Increased metabolism 

• Shivering 

  — If not fixed, things like frostbite and hypothermia can occur

Cold Responses ( Physiological Acclimatization)

• Further metabolic increase 

• Increased red blood cell count 

• Vasoconstriction: In the face of extended cold, out blood vessels may constrict and move inwards in the body to conserve heat. (Help preserve core body temp) (both vasoconstriction and vasodilation occur)

• Cycling of heat to and from extremities (hunting response)

Cold Responses (Adaptations)

• More compact body form 

• Shorter appendages 

• Rounder head shape 

• Narrow, high nasal aperture

• Epicanthic eye folds and cheek pads

  — Helps keep face warmer 

• Light skin color?

  — Darker skin is prone to cold easily

• Also culturally adaptation

Heat Responses (Acclimation)

• Sweating 

  — Cools the surface of the skin and encourages air to circulate around the skin.

• Increased blood circulation to skin 

  — Helps let heat escape 

Heat Responses (Physiological acclimatization)

• Decreased heart rate

  — Helps the body cool easier 

• Increase plasma in blood

  — Helps prevent dehydration 

• Increased sweating

Heat Responses (Adaptation)

• Elongated bodies 

• Longer appendages 

• Longer, narrower heads 

• Cultural adaptation 

High Altitude Responses

Biological adjustments to lower oxygen pressure at high altitudes, including increased respiration, heart rate, and red blood cell production for better oxygen utilization.

High Altitude Responses (Acclimation)

• Increased respiration

• Increased heart rate 

• Increased hemoglobin content in red blood cells 

High Altitude Responses (Physiological and developmental acclimatization)

• Increased number of capillaries 

• Increased lung size 

• Increased production of red blood cells

• Respiration rate returns to normal

• Enlarged right ventricle of the heart 

• Babies born with lower birth weight

High Altitude Responses (Adaptation)

• Elongated bodies 

• Longer appendages 

• Longer, narrower heads 

• Cultural adaptation

Chronic Mountain Sickness (CMS)

Condition occurring in individuals not adapted to high altitudes, leading to symptoms like headaches, dizziness, and memory loss due to prolonged exposure to low oxygen levels.

Variation in Human Traits

Reflects environmental influences during an individual's lifetime, including acclimation, acclimatization, and natural selection for adaptive traits from ancestors' environments.

Variation in growth and development

• Increases in height from 1885 to 1960

• Shifts in menarche (decrease in average age or menarche)

• Females reach skeletal maturation 1-2 years faster than males.

Menarche

Related to the proportion of body fat to body mass.

Why does variation in growth and development occur:

• Where you live, what you eat, how active you are

• Healthier = mature faster, get taller

• Undernutrition - Not consuming enough calories

• Malnutrition - not enough calories of a specific type of nutrients (fat, etc)

  ➔ Ex: Datoga vs. American growth patterns

Best predictor of growth and development: Socio-economic class

• Genetically similar groups in different socio-economic circumstances exhibit

• different average body sizes at all ages.

• Growth patterns and body forms coverage when different ethnic groups occur

• similar environments

  ➔ Another socio-cultural factor is skull shape (baby lying on back)

  ➔ Neck Length, foot form, soft tissue, skin color

Human plasticity:

Important to note: Human body form is a complex product of a variety of different factors.

Ability vs Performance

• When wanting to view someone's athletic performance we really want to measure their

  ability, yet ability can’t be measured. However performance can.

• Whenever studies are viewed by behavioral variation, we are viewing performance and performance doesn’t reflect ability.

Twin study: The positive

Wanted to see if twins share the same behavioral traits. Digging deeper wanted to see if the similarities shared between twins are genetic or environmental. Especially for twins who are separated at birth.

Twin study: The negative

• Coincidence don’t shed light on the genetic basis of behavior

• Identical twins don’t have identical genomes

• Biased enrollment of study subjects

• Twins separated at birth are usually reared in similar environments

Thomas Bouchard

He did a study with twins and found that genetic factors have a large influence on behavioral habits demonstrating the influence of genetics on development.

Linkage Analysis

• Gene hunting technique that uses statistical methods to map a gene to its chromosomal location.

• Used to also identify specific genes that may influence intelligence.

Heritability

• Heritability is not the degree to which a trait is genetically determined.

• Heritability is the proportion of total phenotypic variance due to genetic variance.

Types of group difference

Different averages, but extensive overlap in the overall distribution

1. The speed someone can run. When thinking about this one might see that the average running speed may be different or overlap and some individuals may fall into that category.

2. The average speed is the same, yet the distribution may be different.

3. Both the averages and the overall distribution may be a bit of overlap. Most people who identify as white may be slower than people who identify as black.

why do we need to understand group differences

• Individual vs group variation is important to determine someone's behavioral traits and discover if these traits are genetic based on their environment.

• To really understand how different people behave you have to sample a group of people in a much larger distribution.

Charles Spearman

Created the theory that general intelligence or “g” is correlated with specific abilities or “S” to some degree.

Fractionating human intelligence study entails:

• Reasoning

• Short term memory

• Verbal

Alfred Binet

In 1904 he developed a test that would identify learning disabilities and other academic weaknesses in grade school students.

Lewis Terman

Was the first to conduct an large scale IQ test in the US.

Robert Yerk’s

Alpha beta IQ tests administered to 1.75 million US soldiers during WW1. Note: Moron was a technical term used for people with mental age of 12 or less

Sex

Category based on biological traits 

Gender

Category trait is socially and culturally constructed; social roles 

Klinefelter syndrome

Where boys and men are born with an extra x chromosome (three sex chromosomes XXY phenotypically male).

Turner syndrome

Only one sex chromosomes (x) phenotypically female

XXY syndrome

Three sex chromosomes (XYY)

Sex and Gender spectrum

Gender exists somewhere between male and female, at various points along what is known as the gender spectrum.

Cognitive and Behavioral differences

• No IQ differences between males and females 

• Performance vs. Ability 

• Males have slightly larger brains but females have more neurons

Guevedoces syndrome

Eficiency of a certain enzyme which causes external development of penis and scrotum.

Androgen Insensitivity Syndrome (AIS)

is a rare genetic condition that prevents the body from using male hormones (androgens) during fetal growth and after birth. 

Philippe Rushton

argued that average IQ differences between racial groups are due to genetic causes.

Flynn effect

The phenomenon in which there is a marked increase in intelligence test score averages over time.

The Bell Curve

The Bell Curve may also refer to a controversial book by Charles Murray and Richard J. Herrnstein that links intelligence to class and race in modern society. The book was published in 1994 and argues that intelligence, not environment, is the primary determinant of various social behaviors.