ANTH 1
Introduction to
Physical Anthropology
Study Guide #1
Last Updated: February 20, 2006
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Be sure you:
· understand the difference between a hypothesis and a theory; understand how the Scientific Method works
· understand the concepts of the fixity of species and the Great Chain of Being
· understand the impact of Copernicus’s conception of the universe as heliocentric rather than geocentric
· can associate the following people with their ideas/contributions to the development of evolutionary theory; and,
o Carolus Linnaeus: created binomial classification
o Georges Louis de Buffon: proposed organic evolution occurred
o Jean Baptiste de Lamarck: proposed evolution by the inheritance of acquired characteristics
o Archbishop Ussher world created in 4004 BC
o Georges Cuvier: theory of Catastrophism
o James Hutton & Charles Lyell: principle of Uniformitarianism
o Thomas Malthus: over-reproduction & struggle for existence
o Charles Darwin & Alfred Russell Wallace: proposed evolution via the mechanism of natural selection
Be able to define/understand the following terms:
o Mendelian Genetics
· Gregor Mendel
· Blending vs Particulate or Discrete Inheritance
· Traits: dominant vs recessive
· gene/locus/allele
· Alleles – variants of a gene
· Genotypes: homozygous, heterozygous, hemizygous
· Phenotype
· Generations: P, F1, F2
· Mendel’s Laws: Segregation, Independent Assortment
· Ratios: Genotypic, Phenotypic
· Heterozygous cross: 3:1; Principle Segregation
· Dihybrid heterozygous cross: 9:3:3:1; Principle Independent Assortment
· Punnett Squares
o Molecules of Life:
· Carbohydrates (sugar, starches / monosaccharides, disaccharides)
· Lipids (oils, fats)
· proteins (amino acids),
· nucleic acids
· sugars – ribose, deoxyribose
· phosphate
· bases
· pyrimidines (small bases): cytosine (C) & thymine (T)
· purines (large bases): guanine (G) & adenine (A)
· Deoxyribonucleic Acid, Ribonucleic Acid
o Molecular Genetics
· Understand the structure of DNA:
· double stranded, helical ladder
· backbone: deoxyribose sugar & phosphate group
· rungs:
§ bases joined together by hydrogen bonds
· Understand DNA replication:
· DNA free nucleotides (deoyribose sugar, phosphate, base)
· Understand RNA structure
· types: messenger (mRNA) & transfer (tRNA)
· single stranded
· components: ribose sugar, phosphate group, bases (uracil [U] replaces thymine)
· Understand proteins:
· made up of combinations of 20 amino acids
· each amino acid united to neighbor by peptide bond
· each amino acid coded for by 1 or more DNA /mRNA codons or tRNA anticodons
· there are 1000s of types of proteins in body
· e.g., enzymes, pigments, hormones
· Understand Protein synthesis:
· Genetic Code – 64 codons
· ribosomes: site of synthesis
· transcription: DNA -> mRNA
· translation: mRNA + tRNA + ribosomes -> protein
o Cytogenetics
o somatic cells & sex cells (gametes)
· cellular components
· cell membrane
· cytoplasm
· centrioles/spindle fibers
· nuclear membrane
· chromatin/chromosomes/sister chromatids
· centromere
o Somatic cell division – Mitsosis
o sister chromatids lie along equatorial plane
o results: two identical diploid (N=46) daughter cells
o Sex cell division – Meiosis - gametogenesis
o gonads: testes, ovaries
o two rounds of division
o Independent Assortment and Crossing-Over during Meiosis: produces recombination of genes
o results: four unique haploid (n=23) daughter cells
o Spermatogenesis - sperm (small, mobile);
o Oögenesis - ovum (large & food-filled, immobile) + polar bodies
o differential allocation of cytoplasm due to eccentric position of equatorial plan
o Linked genes – on same chromosome
o zygote/fertilization
· Sex-Determination and X-linked traits:
· chromosome types: autosomal chromosomes, sex chromosomes
· male genotype: XY; female genotype XX
· X-linked traits: color blindness, hemophilia
· ABO Blood Groups:
o antigen, antibody
o three allele system: A & B codominant, O recessive
GENOTYPE PHENOTYPE
-------------------------------------------------------------------------
AA, AO A antigen, anti-B antibody
BB, BO B antigen, anti-A antibody
AB A&B antigens, no antibodies (universal recipient)
OO no antigen, anti-A & anti-B antibodies (universal donor)
· Rh System:
· two allele system: R (antigen present), r (antigen absent)
· placenta, antibodies, lymphocytes
· maternal/fetal incompatability
· Understand the conditions required for natural selection to operate:
· a trait must be heritable
· there must be variation already present in the expression of a trait
· the trait must confer differential reproductive success in a particular environment
· Be able to define the term "adaptation"
·
Be familiar with the "industrial melanism" (moths in
· Example of Natural Selection acting on frequency of alleles:
o sickle-cell trait
o alleles:
o A (or HbA) = normal
o S (or HbS) = sickle-cell allele
o genotypes:
o AA normal
o AS sickle-cell trait/carrier
o SS sickle-cell disease
o malaria - caused by protozoan Plasmodium falciparium
o carried by mosquitoes, which breed in light, warm and wet environments, such as those produced by agricultural (slash + burn) practices
o AS individuals have highest fitness in malarial environments
· Adaptation/Acclimitization: Stresses
· solar radiation
· Population response: Adaptation
· skin color and solar radiation
· function of where populations live relative to equator
· pigments contributing to skin color: melanin & hemoglobin
· melanin absorbs UV light
· epidermis/dermis; melanocytes
· UV light stimulates
· vitamin D production
· too much UV light leads to skin cancer
· too little UV light leads to rickets
· Individual response: acclimitization
· Tanning
· Thermal Stress: Cold, Heat, Body Size & Shape
· High Altitude Stress
· Dietary adaptation:
· lactose intolerance
· lactose = glucose + galactose
· lactase is enzyme that breaks lactose into components
· small intestine = nutrient absorption
· large intestine = water absorption; site of fermentation of lactose (if not broken into glucose + galactose)
Comparative Genetics:
1) DNA Hybridization:
a) Pure DNA melts at 86 degrees centigrade
b) melt DNA of, for example, humans and chimps and snip one strand into shorter fragments
c) mix human and chimp DNA fragments and let cool to form hybrid; complementary bases
join; non-complementary bases don’t join, producing a weaker molecule
d) heat hybrid DNA and see at what temperature it melts: every degree difference in melting temperature is equal to one percent difference in DNA bases.
e) humans and chimps share 97.6% of their DNA
2) Amino Acid Sequences:
a) identify amino acids in beta chain of hemoglobin molecule
b) humans and chimps are identical; gorillas are slightly different from humans/chimps etc.
c) since amino acids are coded for by codons, the sequence of amino acids indicates the degree of genetic similarity
3) Immunological Studies:
a) inject human blood serum into distantly related animal, like a rabbit
b) rabbit produces anti-human antibodies to human antigens
c) extract anti-human antibodies from rabbit
1) mix with human blood: result is complete bonding of antibodies and antigens, producing a large amount of a precipitate
2) mix with gorilla: smaller amount of precipitate is formed, indicating that gorillas share genes for many blood proteins (i.e., antigens)
3) mix
with
4) mix with lemur: ditto
4) DNA Fingerprinting
a) 100,000 genes (5-10% of the genome)
b) non-coding DNA – hypervariable
1) mini- (16-64 bp) & microsatellites (3-6 bp)
c) Electrophoresis
5) Taxonomic Level of analysis is important in choosing which protein to use
-depending upon the function of the protein, its structure may or may not be important
-if function requires a specific structure (e.g., histones) then mutations are not allowed to accumulate
-if function does not require specific structure (e.g., fibrinopeptides) then mutations are allowed to accumulate
-for very distantly related taxa (e.g., humans and horses) a more slowly mutating gene for a protein will be useful for analysis of evolutionary relationships
-for closely related taxa (e.g., humans, chimps, gorillas, gibbons, Old World monkeys) a more quickly mutating gene for a protein will be useful for analysis of evolutionary relationships
Understand the Causes of Evolution:
· Main processes: Mutation, Gene Flow, Genetic Drift, Natural Selection (stabilizing, directional, diversifying)
· Mutation: ultimate source of variation
1. mutation:
o molecular level: point mutation
o chromosomal level: number & structure
1. Chromosomal Number
1. Due to non-disjunction
1. Autosomal chromosomes
1. e.g., Down Syndrome (Trisomy 21)
2. Sex Chromosomes
1. Turner’s Syndrome: X-; phenotypically female, short, normal IQ, sterile, neck webbing, small chin
2. Klinefelter’s Syndrome: XXY; phenotypically male, normal IQ, sterile, small penis, large breasts
3. Supermales: XYY
2. Structural modifications: Deletion, Duplication, Inversion, Translocation
2. Gene Flow
3. Genetic Drift
4. Natural Selection
5. Sexuall Selection
· Ancillary processes: Non-random mating a.k.a. assortative mating (positive and negative); recombination
Understand:
· Biological Species Concept
· Reproductive Isolating Mechanisms
· Premating: ecological, seasonal, behavioral, mechanical
· Postmating: gametic mortality, hybrid inviability, hybrid sterility (H+D=M)
Understand models for the Origin of Species
· Micro- & Macroevolution
1. deme/subspp/spp
2. cline/gradient
· Speciation: geographical isolation/allopatric
· Test of Speciation: Sympatry
Understand the concept of Convergence and Homology and know some examples