anthro

The study of humankind in a cross-cultural context

The study of human societies from a cross-cultural perspective

The study of the material remains (i.e.) artifacts of past human cultures

Study of one aspect of human culture, language, and its origins, structures, and use

Study of humans as biological organisms within an evolutionary framework OR the scientific study of human beings as biological creatures.
- Considers what we share with other animals and primates
- what makes us unique.

- Primatology
- Paleoanthropology
- Skeletal biology
- Human biology
- Forensic anthropology
- Anthropological genetics
- Evolutionary neuroscience

An approach to gaining information about natural phenomena through observation and experimentation
- Empirical: Knowledge-based and gained through observation

1. Observation and description of natural phenomena
2. Formulation of a hypothesis to explain phenomena, with clearly stated predictions that must be falsifiable
3. Hypothesis testing against empirical evidence
4. If the hypothesis is not falsified after repeated empirical testing than it can be a theory

Robustly supported set of generalizations that allow us to predict what happens under particular conditions and why

- Factual, explain how, testable
- An explanatory theory that has been repeatedly tested, supported by the overwhelming amount of consistent evidence, and has withstood attempts to disprove its core concepts

1. Empirical
2. Self-correcting process (falsifiable)

Change over time (not necessarily improvement)
For example, The consumption of music has shifted from record players to spotify

From the 6th century BC, ancient greek evolutionary ideas
- Sought natural causes for biological and other earthly phenomenon
- Notion of change: humans and other animals descended from fish

From 473-347 BC, Ancient Greek evolutionary ideas in the context of the republic.
- Concept of eidos, an abstract "form: that is imperfectly imitated in the real world
- Species have a defining "essence" that is fixed and unchangeable

From 384-322 BC, ancient greek evolutionary ideas,
- appreciated organic diversity
- organized and classified organisms into a "scala naturae" or a great chain of being which places humans at the top

From 776-868 AD, Iraq, Muslim Evolutionary scholar
- Created Kitab Al-Hayawah (book of animals) which details an evolutionary theory similar in man ways to natural selection
- Emphasized the role of the environment in the evolution of human traits (ie. skin color)

from 930-1030 AD, Persia, Muslim Evolutionary Scholar
- Stated that humans evolved from other animals in a progressive, step-by-step process
- Differences between humans and animals seen as intellect which was a divine gift

from 973-1048 AD, Turkmenistan/Uzbekistan, Muslim evolutionary scholar
- Similar to Ibn Miskawayan, Al-beruni held the view that humans migrated through various "lower" lifeforms on the way towards humanity
- Noting similarity between monkeys and humans, he stated monkeys were the final through which humans passed before coming human

from 1332-1406 AD, Tunisia, Muslim Evolutionary Theorist
- clearly expressed idea of progressive evolution, explicitly stating humans evolved from monkeys
- Explicitly rejected religious explanations for differences in skin color and pointed out the latitudinal gradient which linked dark skin to hot climates

from 1518-1593, Chinese theorist
- organisms influenced by the environment
- described artificial selection by emphasizing the heritability of traits the same way Darwin would come to natural selection
- utilized binomial system of naming organisms
- utilized hierarchical classification scheme

In the European middle ages
- From plato
- Doesn't allow from change

In the European middle ages
- from Aristotle which placed humans on top, under god

In the European middle ages
- bases explanations of organisms and their features on function

In the European middle ages
- Believed October 23rd, 4004 BC was the beginning of the earth

Didn't allow for logical explanations for evolution and change

- 1707-1778
- Systema Naturae (1735)
- Binomial System

Created hierarchical system of classification based on similarities
TOP
Kingdom (Animalia)
Phylum (Chordata)
Class (Mammalia)
Order (primates)
Family (hominidae)
Genus (homo)
Species (sapiens)
BOTTOM

Label based on genus and species, for example homo (genus) sapiens (species)

- 1707-1788, pre-Darwinian thinker
- Histore naturalle (1749)
- Animals that migrate to new climates often change in response to new environments
- Similar to Al-Jahiz and Ibn-Khaldun who preceded him, he suggested that external environment is important for biological change
- Variation observed in organisms reflect environmental influences

- from 1744-1829, pre-Darwinian thinker
- Philosophie zoologique (1809)
- Proposed a now discredited mechanism of biological change to explain biological diversity
- This mechanism suggested organisms interact in a dynamic way with their environments which has importance for producing evolutionary change

Determined by
- use or disuse
- Inheritance
For example: giraffes neck, incorrectly assumed evolutionary change occurred during a single lifetime

- from 1797-1875
- At the time of his existence, most thinkers believed in a very young earth, which left no time for large-scale biological change
- Principles of Geology (1830-1833) suggested uniformitarianism and deep time which provided the time frame needed for the acceptance of organic change

- Appreciation of diversity in the natural world and methods of classifying diversity (naturalists everywhere)
- notion of organic change
- environment as an important agent of organic change
- ancient origin of the natural world

1809- 1882

- the ship Darwin took his voyage on from 1831 to 1836
- this trip changed his thought processes

1. observation of the diversity of Flora and Fauna on his voyage aboard the HMS vehicle
2. experience of earthquake in Chile
3. in Argentina, Darwin collected fossil bones of extinct animal forms such as the Giants sloth
4. observation of diversity and ground finches across Galapagos Island chain
5. reading Thomas Malthus's essay on the principle of the population from 1798
6. observation of the power of artificial plant and animal breeding

- generated "an essay on the principle of population" 1798
- human populations have the ability to increase exponentially at a rate that is faster than food production
- populations around the world tend to be stable
- there is a struggle for existence

Individuals of a species with advantageous characteristics/adaptations would be more likely to survive and limiting conditions and thus would respond and reproduce more successfully than those with less advantageous attributes

very devout, Darwin did not want to bring dishonor to those he loved through his scientific work

1836: Darwin returns from The Voyage of HMS beag
1844: Darwin prepared his first lengthy sketch on his theory of evolution by means of natural selection
1858: Darwin receives a manuscript that Wallace had independently conceived evolution by means of natural selection
1858: Darwin and Wallace present their ideas to linnean society in London

1859 body of work produced by Darwin
- biological evolution is fact
- common descent with modification
- Gradualism
- natural selection is the mechanism of evolution

natural selection

wherever there is heritability, variability, the struggle for existence, differential reproductions/survivability

reproductive success

Changes in response to new or varying environmental stressors / pressures
- occurs and response to particular environmental conditions

may be a force in the Origin of Species

diversity observed among species is the result of evolutionary relatedness ( time from common ancestor) and adaptation

Manchester, England
changes in pigmentations as a result of the Industrial Revolution

pre-industrial revolution: 99% were light gray, 1% were dark

post-industrial revolution: 10% were light gray, 90% were dark gray

many rejected it and hoped it would not become known

light will be thrown on the origin of man and his history (1859)

a pre-DNA concept of inheritance

parental contribution is averaged out, or Blended, in offspring

1822 to 1884

undertook a systematic investigation of inheritance using very large numbers of pea plants

demonstrated particulate inheritance through this testing

Male: stamen (anther, filiment)

Female: carpel ( stigma, Style, ovary)

most plants are hermaphrodite, meaning they can contain organs of both female and male plants

cross-fertilization is achieved via cross-pollination

1. easy to control pollination
2. it shows variation in a number of different trials
3. pure breeding lines could be identified

F1( first filial generation)
cell progeny had yellow feeds despite variation among parents

green/wrinkled variant reappeared unchanged

each hereditary characteristic is controlled by particulate unit factors (genes), which exist in pairs in individual organisms; one factor is inherited from each parent

these factors remain discrete I.e. unchanged regardless of external appearance

when two different unit factors relate to a characteristic, only one is expressed (dominant) while the other is not in (recessive)

there must be two copies of the factor present for the recessive form to be expressed

the observable or detectable expression (appearance) of a trait

the full set of genetic factors that interact in determining the phenotype

when two copies of the same genetic Factor controlling a trait are present in an individual (= true breeding lines)

when two different genetic factors for a trait are present in an individual

during the formation of the sex cells ie. gametes, the paired unit/hereditary factors separate or segregate randomly such that each gamete or sperm or egg receives one or the other factor with equal likelihood

two traits considered in combination

- seed shape
R = round
r = wrinkled

- Seed color
Y= yellow
y= green

the distribution of one pair of factors into the gametes does not influence the distribution of other factors

for example seed color is inherited independently of shape

Exception: applies to genes located on different chromosomes, but genes located on same chromosome (linkage is different)

particulate inheritance

Dominance

law of segregation

Law of Independent Assortment

deoxyribonucleic acid

genetic material that encodes for the expression of a particular trait

location of a gene on a chromosome

alternative versions of a gene; one gene but two or more alleles

individuals complete set of chromosomes

both chromatids and a chromosome are identical (results of the replication of DNA molecule)

one from mother, one from father, may carry different alleles for the same traits, same loci different alleles

46 chromosomes, 23 pairs

1-22 Autosomes

23= sex chromosomes (X&Y)

Male-xy
female-XX

somatic and sex cells

components of body tissue

23 chromosome pairs

Ova: egg cells produced in female ovaries

sperm: sex cells produced in male testes

zygote: Union between sperm and ovum

diploid: both members of chromosome pair

haploid: only one number of each chromosome pair

mitosis - somatic cells
Meiosis - sex cells

somatic cell division

during growth and repaireplacement of tissues

The result is two identical daughter cells

identical to the original cell generally (two diploid cells)

DNA replication

chromosomes visible with two identical sister chromatid

chromosomes line up single file along the Equator of the cell

sister chromatids separate

results in two daughter cells (diploid) with identical copies of genetic material

production of gametes (sex cells)

characterized by two rounds of division that result in four daughters, Each of which contains 23 chromosomes (4 haploid cells) in humans

fertilization restores the full complement of chromosomes (Diploid number of 46) to the zygote

creates new variants

DNA replication

Crossing over (genetic recombination)

Chromosmes aline in homologous pairs; A random assortment of chromosome members with respect to either side of the Equator

chromosome pairs separate (reduction division)

Two haploid daughter cels, which are genetically dissimilar; no DNA replication

Each daughter cell inherits half as many chromosomes as the original cell, only one member of each homologous pair (i.e., haploid)

each chromosome has two chromatids, but they are different because of crossing over

there has been recombination of genetic material from the mother and father

the first division is meiosis I: the number of cells is doubled, but the number of chromosomes is not. This results in 1/2 as many chromosomes per cell.

The second division is meiosis II: this division is like mitosis; the number of chromosomes does not get reduced

meiosis increases genetic variation through
- crossing over
- random assortment
- Mutation

provides raw material for natural selection to act upon

1. accurate replication
2. stable structure
3. capable of coding for diverse information including proteins
4. capable of transmitting this information to regulate development and normal cell functioning

Nucleotides

a nucleic acid
- resides in nucleus of the cell
- stores and transmits information
- made up of smaller molecules called nucleotides

- Two fused rings: adenine and guanine
- One single ring: thymine and cytosine

each nucleotide contains one of four different bases with one exception

structural differences have important consequences for nucleotide matching

x-ray diffraction photos provided Clues to the structure of DNA

1953, Discovered DNA

- located in the nucleus of the cell
- Double helix structure
- compromise of nucleotides
1. Phosphate
2. Sugar (deoxyribose)
3. nitrogenous base

Adenine (Two fused rings) - thymine(One single ring)

cytosine(One single ring) - guanine (Two fused rings)

complimentary chains (specificity of base pairing) provide a mechanism by which the molecule can replicate itself

the sequence of nucleotide base is varied and contains important information (genetic code)

Replication (Cell division)

protein synthesis
(genotype to phenotype)

- occurs during cell division
- original strand, leaving their bases exposed
- original strands are templates for two complementary strands
- this results in two identical copies of the DNA molecule

genotype= underlying genes

phenotype= physical outcome

proteins may serve as structural components of body tissues or Play Active functional roles

- amino acid subunits are linked together to form linear polypeptide chains
- 20 different amino acids
- amino acids can be combined in different amounts and sequences to produce different proteins
- different polypeptide chains can be assorted to form complex multimeric proteins

information to make protein is encoded in the nucleotide-based sequence

a sequence of three nucleotide bases that code for one amino acid
Ex. ACC, Threonine

64

Redundancy

many amino acids are specified by more than one codon sequence

this means that many mutations are synonymous and do not change the amino acid produced

the sequence of DNA bases that carries information for synthesizing a particular protein, and occupies a specific chromosomal locus

at ribosomes outside cell nucleus, but DNA can't leave the nucleus

Single-stranded whereas DNA is double-stranded

ribose sugar whereas DNA is deoxyribose sugar

Uracil base whereas DNA is thymine base

happens inside the nucleus

DNA splits only in region of gene, in attracts complementary ribonucleotides

Complementary messenger RNA (mRNA) stranded is synthesized: this mRNA will leave the nucleus and travel to the ribosome for protein synthesis

Happens outside the nucleus, at the ribosome

Transfer RNA or tRNA molecules bind to the complementary mRNA strand at the ribosome, bringing with them amino acids specified by the mRNA codon

as amino acids are brought to ribosome they bind together to form amino acid chain of the synthesized protein

as they are synthesized with the assistance of proteins called chaperones

An alteration in the genetic code; source of new variants

When mutation occurs at the level of the nucleotide base it may or may not alter function

- chromosomal mutations
- point mutations (1 Point changes)
-Duplication (a sequence repeats)
-Inversion (a sequence inverts)
-Deletions (frame-shift)

is a change in the DNA sequence that codes for amino acids in a protein sequence but does not change the encoded amino acid

Change to a functionally equivalent amino acid

constantly occurring at random; may be induced by other agents

mutations may be functionally irrelevant; though if they are functionally significant many are lethal or have negative consequences. some can have neutral effects

a small proportion may be beneficial and confer selective advantages

if a mutation occurs during meiosis and it may be passed to the Next Generation

a single Gene, autosomal dominant-recessive model

useful for examining traits with qualitative variation (discrete categories) Ex. Pea seed color, cystic fibrosis, dimples

both alleles in the heterozygous condition are fully Expressed, with neither being dominant over the other ex. ABO blood system

controlled by genes on the X chromosome, more commonly expressed in males. as males (XY) have only one X chromosome, any allele will be expressed, whether dominant or recessive ex. red-green color blindness

traits with quantitative (continuous) variation influenced by two or more genes Ex. Stature, skin color, eye color

a single Gene influences the expression of multiple traits simultaneously ex. Marfan syndrome

Many aspecdts of the phenotype are influenced by the interaction of genomes and the environment

Genotype sets limits and potential for developmental processes

1. Structural genes
2. Regulatory gens such as homeotic genes

- 99%

- Differences have emerged from very few changes in regulatory genes with pronounced downstream effects

Introns

Pseudogenes: primates have a higher proportion of olfactory pseudogenes than other mammals

A group of organisms potentially capable of successful reproduction

individuals of a population tend to choose mates from within the group

largest reproductive population is the species

Population

the sum of all alleles carried by the members of a population

Allele frequencies
- E-Sticky earwax (40%)
- E- Dry, flaky earwax (60%)

Genotype frequencies
- EE - Homozygous dominant (16%)
- Ee - heterozygous (48%)
ee - homozygous recessive (36%)

a change in allele frequencies in a population from one generation to the next

no changes in allele frequencies. Ie.e., no evolution is occurring in the population

- used to determine whether or not evolutionary forces are operating on the population for a given genetic locus

- measure observed genotype frequencies for specific traits and compare them against predicted genotype frequencies assuming no evolution is occurring

- In essence, provides a genetic model (null hypothesis) against which we can compare observed genotype frequencies in a population, to determine whether evolution is occurring at a given genetic locus

P= frequency of dominant allele
q=frequency of recessive allele

p+q = 1

p^2 + 2pq + q^2 = 1

P^2: chances of A combining with A (pxp) (AA)

2pq: Chances of A combining with a and a combing with A (pxq) (Aa & aA)

q^2: chances of a combining with a (qxq) (aa)

.25+ .5+.25=1

pxp=p^2:=.5x.5 = .25

pxq & qxp = 2pq = (.5x.5)+(.5x.5)=.50

qxq=q^2=.5x.5=.25

- an alteration in the genetic material
- mutations are chance events
- mutations are rare events
- mutations give rise to new alleles
- mutations add variation to the gene pool

Alleles that confer an increased likelihood of survival to reproduction will be passed on to the next generation with greater frequency

maintains a certain phenotype by selecting against deviations from it

Selection for greater or lesser frequency of a given trait

maintains extreme values in the population

Change in gene frequency in a population over time, caused by entirely random factors

- sampling error effects: more likely to change the frequency of alleles in a small population

- Population bottle necks
- founder effect

Movement of individuals and their genes between populations

- makes populations more similar to one another

- counteracts the evolutionary forces that cause populations to diversify

- Inbreeding
- assortative mating

raises the frequency of homozygous genotypes at all loci and decreases frequency of heterozygous genotypes

Negative AM: increases frequency of heterozygous genotypes for particular loci

Positive AM: increases frequency of homozygous genotypes for particular loci

1. mutation
2. Natural selection
3. Genetic Drift
4. Gene flow
5. Nonrandom mating

*hardy Weinberg assumes these forces are not operating

Small changes occurring within a species, such as changes in allele frequencies

large changes produced after many generations, such as the appearance of new species

part of the same continuum of evolutionary processes

Evolutionary lineages (ancestral-descendant sequences of populations) with their own unique identity

Groups of inter-breeding natural populations which are reproductively isolated from other such groups

Physical barriers such as geography or intrinsic barriers such as physiology and behavior

- habitat isolation
- temporal isolation
- behavioral isolation
- mechanical incompatibility

- sperm/egg incompatibility
- inviability of the zygote-fetus or offspring
- offspring sterility

a group of organisms exploiting a single ecological adaptation

Defines species based on anatomical similarities
- not always reliable because species can be polymorphic and different species can be very similar
- sometimes is the only one that can be used (paleontology)

Each species within an anagenetic line

1. Allopatric
2. parapatric
3. sympatric

Speciation occurring via complete geographic isolation

speciation involving only partial geographic isolation

speciation occurring in the absence of geographic isolation

Gradually

How species "makes a living," which includes how it interacts with its environments with other species in its community and how it utilizes resources in its habitat
- species that live together in the same habitat must have different niches in order to avoid being in direct competition with other species

When a single kind of organism diversifies to fill many available niches. e.g. ancestral lemur makes it to Madagascar 50+ million years ago

Evolutionary change proceeds gradually through accumulated small-scale changes

evolutionary change proceeds through long periods of stasis and rapid periods of change

- Natural selection acting on traits, as well as genetic drift

Examples: skin color, sickle cell anemia, lactose tolerance, body size, and shape

Cells in the epidermis
- keratinocytes
- melanocytes

produce keratin, which affords protection against water and abrasion

produce the pigment in melanin
- Melanin is a major contributor to skin color

Hemoglobin (blood protein - pink color)

Keratin (yellowish protein in skin/hair)

Melanin (dark brown pigment, the main determinant of skin color)

number of melanin-producing cells is approximately the same in all individuals, but the amount of melanin deposited varies

Dark skin = synthesis of large amounts of melanin

Light skin = synthesis of less melanin

Freckles = localized production of lots of melanin

a polygenic trait influenced by a number of different genes

a clinal distribution

variation along an environmental gradient

-high-energy and non-visible radiation contained in sunlight; causes DNA damage
-intensity increases greatest at the equato, decreases toward poles

Natural skin selection and skin color

1) Skin damage and skin cancer
2) nutrient photolysis: folic acid
3) Vitamin D synthesis

-Sunburn: destroys skin cells, increases rate of skin infection
-Skin cancer: different types, some are deadly
-natural selection favors more melanin production (darker skin) in areas of high UV radiation as protection from skin cancer and skin damage
-lighter skin individuals are selected against, pass on their genes at lower rates

-some essential nutrients undergo decomposition (photolysis) when exposed to UV radiation
-Darker skin affords protection from the depleting effects of UV radiation
-natural selection favors more melanin production (darker skin) in areas of high IV radiation as protection against nutrient photolysis
-lighter skin individuals are selected against, pass on their genes at lower rates

-important for central nervous system development
-deficiencies can lead to pregnancy complications, neural tube defects, impaired sperm production

-vitamin D is essential for calcium metabolism and normal bone and tooth development
-difficult to obtain from diet: scare in foods except for oils, butter, cream
-primary source of vitamin D is synthesis within the skin: synthesized through interaction of UV light and cholesterol-like substance in epidermal cells
-natural selection favors lower melanin production (lighter skin) in areas of low UV radiation, to make best use of scarce UV for adequate vitamin D production
-darker skin individuals are selected against, pass on genes at lower rates

Rickets: a disease affecting children, caused by vitamin D deficiency. Results in impaired mineralization of developing bones and teeth
- Legs and pelvis are particularly affected

-Modern human originated from Africa and were probably dark skinned
-Result: clinal distribution or gradient
-only recently populations in nothern high latitudes evolved lighter skin color

-a genetic disorder that causes abnormal hemoglobin, resulting in some red blood cells assuming an abnormal sickle shape
-Single point muatuon in hemoglobin gene
-Genotypes:
HbA HbA (homozygous normal)
HbS HbS ( homozygous sickle cell variant - SCA)
HbA HbS (heterozygous

-Occurrence of two or more different phenotypes in a population, in which natural selection prevents any of the alternative alleles from becoming fixed or becoming lost
-Maintained by heterozygote advantage, in which there is selection against both allelesin the homozygous condition, and a selective advantage of the heterozygous condition

-lactase enzyme breaks up lactose into constituent parts
-most mammals lose the ability to produce lactase after weaning

The gradient is in correlation to latitude/proximity to the equator

The trend applies less so to the north american area because migration patterns differ

High-energy and non-visible radiation contained in sunlight; causes DNA damage

greatest at the equator, decreases towards the poles

Melanin blocks the UV portion of sunlight from penetrating through the skin... it acts like natural sunscreen!

Skin damage and skin cancer
Nutrient photolysis: folic acid
Vitamin D synthesis

destroys skin cells and increases the rate of skin infection

- Dangerous in areas where people do not have routine access to medical care

Natural selection favors more melanin production (darker skin) in areas of high UV radiation as protection from skin cancer and skin damage.

- Lighter skin individuals are selected against and pass on their genes at lower rates.

Some essential nutrients (folic acid) undergo decomposition (photolysis) when exposed to UV radiation
- Darker skin affords protection from the depleting effects of UV radiation

Important for central nervous system development

Deficiencies can lead to pregnancy complications, neural tube defects, impaired sperm production.
Ex. Spina Bifida

Natural selection favors more melanin production (darker skin) in areas of high UV radiation as protection against nutrient photolysis.
- Lighter skin individuals are selected against and pass on their genes at lower rates.

Vitamin D is essential for calcium metabolism and normal bone and tooth development.
- Difficult to obtain from the diet
Scares in most foods except for fish oils, egg yolk, butter, cream, and liver

(This exists in more industrialized food systems but not as much in less industrialized food systems)

Synthesis through the interaction of UV light and a cholesterol-like substance found in epidermal cells

Natural selection favors lower melanin production (lighter skin) in areas of low UV radiation to make the best use of Scarce UV for adequate vitamin D production

- Darker skin individuals are selected against, produce their genes at lower rates

Modern humans originated in Africa and were probably dark-skinned

- Only recently, populations in northern high latitudes evolved lighter skin color (due to relaxed selection on dark skin and direct selection to absorb more UV to make vitamin D)

This clinal perspective contrasts the racist descriptions of how skin color varies

Result of a single-point mutation in the hemoglobin gene
- Hemoglobin helps the red blood cell carry oxygen

(If your blood is not able to get oxygen to all of your muscles, you will experience extreme fatigue)

HbA HbA (homozygous normal)

HbS HbS (homozygous sickle cell various - SCA)

HbA HbS (heterozygous - incomplete dominance, SC trait, some sickling occurs in low oxygen situations - They dont experience bad impacts during their normal life_

The places where a sickle cell is common are also places where malaria is common/endemic

- The frequency of S allele is high in areas where malaria is endemic
- Sickle blood cells don't suffer from malaria

But if you have the trait in heterozygous form
You dont have enough sickle cells to cause full-blown anemia, but also are less susceptible to malaria

in favor of heterozygotes HbA HbS

Maintained by heterozygote advantage, in which there is selection against both alleles in the homozygous condition, and a selective advantage of the heterozygous condition

Lactase enzyme!

Lactase enzyme breaks up lactose into constituent parts to process

Most mammals lose the ability to produce lactase after weaning
Bc, most mammals stop drinking milk

Two Alleles

LCT*P (dominant) lactase persistence
Allows you to drink milk into adulthood even if you only have one copy of this allele

LCT*R (recessive) lactase intolerance

European populations tend to have low intolerance

African populations have a wide range of lactose intolerance

Asian populations have a high level of lactose intolerance

Lactose tolerance evolved by recent natural selection favoring lactase-persistent individuals in a culture that rely on dairy products

individuals living in colder habitats tend to have larger body sizes: less heat lost through body surface

extremities tend to be longer relative to body size in warmer climates to dissipate heat

Ex. Arctic hair vs. antelope jackrabbit

yes

farther away from the equator

tend to be closer to the equator

caused by mutation, results in a permanent production of lactase enzyme into adulthood (unusual for grown-up mammals)

- Mutation is neutral in cultures with no dairying tradition

- The mutation is beneficial in cultures with dairying tradition

Stable polymorphism (occurrence of 2 or more different phenotypes) in a population, in which natural selection prevents any of the alternative alleles from becoming fixed or becoming lost

Percent of population that has sickle cell allele is high in tropical Africa

HbA HbA:85 (very normal/high fitness)

HbS HbS: 0.00-0.33 (very low fitness)

HbA HbS: 1.00 (Very high fitness)

More melanin to protect from skin damage and photolysis at low latitude

Less melanin to facilitate vitamin D synthesis at high latitudes.

Result: clinal distribution or gradient

Rickets: a disease affecting children, caused by vitamin D deficiency, results in impaired mineralization of developing bones and teeth

- Legs and pelvis are particularly affected: fitness can decrease due to impaired movement and problems in childbearing

different types; some are deadly
- The highest incidence of skin cancer in light-skinned people, particularly those living in tropical zones; the low incidence in dark-skinned populations

Race is a genetically distinct and usually geographically isolated population of a species. Zoologists generally now use the term subspecies instead.
- modern understandings of variation don't fit this definition of race

Race science has perpetuated hierarchical social constructs of race which have profound consequences on people today

Different definitions across the world, but in the US, common beliefs about race include:

- The human species can be naturally divided into a few distinct races
- Members of different races are genetically different in important ways, so knowing a person's race gives you important information about what they are like
- The difference between races is due to biological heritage

These are INCONSISTENT with modern understanding of human biology

- Origins of anthropological ideas about human origins were established during the period of violent European colonial expansion

- Scientific ideas about human diversity were used to explain and justify the political dominance of colonizers

- Categorized humankind into five groups

- Established scientific ideas that humans could be categorized into a small number of discrete races... this idea endures for centuries until today

Schemes of racial categorization change over time
- Linnaeus was a European biologist who attempted to classify people into small numbers of categories

- The lack of consensus on how humans should be racially classified shows that these categories are not scientifically grounded

attempt to offer biological support for race categorizations

- focused on their work on ideas of racial difference

- Morton amassed and measured a huge collection of human skulls from around the world, in order to try and give scientific justification to pre-existing racial categories

- Used as justification for atrocities including the Indian removal act of 1830

the study of measurements/proportions of the human body

subfield (anthropometry) focused on crania

1. caucasion
2. mongolian
3. ethiopian
4. american
5. malay

1. americus
2. europaeus
3. asiaticus
4. afer
5. monstrosus

The major method of early bio-anthropologists
- now there is little or no connection between skull shape or size the thoughts/actions of a person

Skull shape and size were used to categorize races and infer behavior and intelligence which we now know there is little or no connection to thoughts/action

- Biologists and anthropologists aimed to apply Darwin's ideas to 'improve' human races
- Developed a national breeding program for the USA with the expressed goal of eliminating disabled people and keeping races separate
- Aimed at maintaining white race and white society, including the development of laws for:
Immigration, sterilization, anti-miscegenation
- American eugenics movement served as a model for similar efforts later in nazi germany

1900s two anthropologists worked on a committee of anthropologists to study the anatomy of black people
- committee's work had multiple outcomes including
- Attempting to show that black people were evolutionarily closer to apes than white people were & Established multiple stereotypes about black athleticism

German-born anthropologist working at USC

- that cranial form (anthropometry) was not genetically fixed, but influenced by the environment

- Boas became found of modern academic anthropology, fought existing racial typologies

- Rejected the idea that humans could be divided into discreet biological groups, citing the importance of adaptation to the environment

argued that different races evolved at different times, happening during the civil rights movement so this was instrumental in political arguments for segregation
-His book directly contradicted Darwin's ideas that the first humans evolved in Africa, which we now know is true from fossil and genetic evidence

championed by Sherwood Washburn - argued the field must move away from classification towards the processes of evolutionary change

the first african american to earn a Ph.D. in biological anthropology showed conclusively that african americans could not be considered a distinct biological race, focused on the detrimental effects of anti-black racism on the body

Humans are phenotypically diverse
Human genetic diversity is surprisingly low. Why?
- A relatively recent bottleneck event in human evolutionary history
- Geneflow between different human populations due to migration
- The evidence stacks up against racial categories

traits that differ across the globe don't line up with one another which they would if race were a good biological descriptor of human variation