Anth 2 Midterm

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Terms in this set (...)

Scientific Method
An ongoing process; Observations-Form a Hypothesis-Collect Data-Finalize and interpret your results
Hypothesis
A proposed explanation for a scientific observation. Not guesses
Misconceptions of Science
1. Its complete
2.Scientific ideas are unchanging
3.Science cant be trusted
4.Science proves or disproves ideas
-Ideas are accepted or rejected based on evidence
5.Scientific theories are guesses
6. Science disproves God
Theories
Explanations for a natural phenomena that is supported by significant evidence
Evolution
Change in allele frequency over time
Adaptations
Existing features that help organisms survive and reproduce
Natural Selection
Process by which existing traits in a population are more suited to an environment and have a higher chance of being passed on
Misconceptions of Evolution
1.Its just a theory
2.Humans evolved from chimpanzees
3.Evolution has an agenda
Evolutionary Thought before Darwin
Creationism; Humans and animals are separate;Great chain of being( with God on top and stones at the bottom);Species don't change
Darwins 3 Postulates
1. There is a struggle for existence
2.Theres variation in features related to survival and reproduction
3.This variation is passed on from gen to gen
Types of N.S.
-Directional selection
-Stabilizing selection
-Disruptive selection
-Sexual selection
Misconceptions of N.S.
1. N.S. involves organisms trying to adapt
2. N.S. gives organisms what they need
3. Humans cant impact ecosystems b/c organisms will just adapt
4.N.S. acts for the good of the species
5. The fittest in a species are those that are the strongest, healthiest, fastest, or largest
6.N.S. is about the survival of the fittest
7.N.S. produces organisms perfectly suited to their env
Complex Traits
Develops over small adaptations. These adaptations must be favored by natural selection
Principles of the Modern Synthesis
1.Mutation
2.Reproduction
3.Gene flow
4.Gene Drift( change of allele frequency)
5.Natural Selection
Forces of Evolution(Also ways in which variation +/-)
1. Natural Selection
-Sexual selection
2.Gene flow
3.Mutation
4.Genetic Drift
Ecological Speciation
Reproductive isolation unnecessary; Natural Selection defines the lines between species
Biological Speciation
Species are groups of interbreeding organisms; Reproductive isolation
Allopatric Speciation
Geographic isolation
Parapatric Speciation
No barrier but gene flow reduced across space. New species arise when members inhabit different habitats and develop behaviors and characteristics that make them better suited to their habitats and thus only interbreed with those of there habitat.
Sympatric Speciation
When selection is strong it can favor different phenotypes within a similar environment leading to new species.
Ancestral Traits
A traits of a common ancestor between all species under consideration
Derived Traits
Traits evolved from the last common ancestor
Race Concept(These are all misconceptions)
1. Humans can be naturally divided into small # of distinct races
2. Phenotype is a good predictor of race
3. Different races vary in important & predictable ways
4. Differences btwn races are due to biological heritage
Cline
A gradual change in the frequency of a trait or allele in pops dispersed across space
Evolution of skin pigmentation
Melanin levels are what impact skin color. Dark skin color arises in areas with a high concentration of UVB to limit control their vitamin D and B levels, which impacts reproduction and chances of skin cancer
SRY Gene
A gene on the Y chromosome that determines the development of testis/ male geneder. When it is present it will lead to the development of testis, when absent it will not, and when it is inactive most will develop as females.
Homologous
Shared trait due to a common ancestor
Analogous
Similar features arising from convergent evolution
Primate Characteristics
1.Grasping hands and feet
2.Stereoscopic vision
3.Long juvenile periods
4.Relative large brains
5.Unique dental pattern
-incisors, canines,premolars,unspecialized molars
6.Dietary plasticity
7.Most live in groups
Mammal Characteristics
1.Hair/fur
2.Mammary glands
3.3 middle ear bones
Strepsirhines
Wet-nosed;post orbital bar;tooth comb;smaller brain;reflective eyes.

Divided into 2 infraorders:Lemuriformes(lemurs) & Lorisiformes(lorises & galagos)
Lemuriformes
Experienced adaptive radiation in madagascar; Very diverse;vertical climbers and leapers;arboreal &semi-terrestrial
Lorisiformes
Small,arboreal,nocturnal,solitary
Haplorhines
Dry-nose;post orbital closure;large brain

Divided into 3 infraorders: tarsiformes, platyrrhini(NWM),catarrhini(OWM)
Platyrrhini Families
Cebdae,Ateldae,Pithecidae,
Platyrrhini
Live in Cen & S. America, arboreal, strong tails, flat nose w/ outward facing nostrils, 2-1-3-3
Catarrhini
Africa & Asia, larger body type and more diverse habitats, some arboreal & some terrestrial, nostrils narrow & downward facing, 2-1-2-3
Mendels principles
1.Characteristics of Organisms are determined by 2 genes, one from each parent.
2.Each of these genes are equally likely to be transmitted when gametes are formed
Allele Frequency
# of specific allele in pop./total # of allleles in pop
Hardy-Weinberg Equilibrium
p^2+2pq+q^2=1
Mode 1 (oldowan)
Homo habilis or Aus garhi/ Composed of flakes, hammer stones, and cores
Mode 2 (Acheulean)
Homo Erectus/ Composed of bifaces or stone hand axes. Designed for carcass processing.
Mode 3 (Mousterian)
Homo heidelbergensis/ Symmetric flakes off cores. Tools were carefully constructed and touched up. Template for tool making
Mode 4 (upper Paleolithic)
Homo Sapiens/ Blades, chisels, drills, harpoons, etc. Used different materials
Ardi/ Lucy/ Taung Child/ Floresiensis/ Naledi
Ardi- Ardipithecus Ramidus; 4.4 mya; Aramis, Ethiopia; Most complete early hominid specimen/ Lucy- Australopithecus Afarensis; 3-3.6 mya; Ethiopia, Tanzania/ Taung Child- Aus. Africanus; 2.2-3 mya; Challenged large brain first idea; South Africa/ Floresiensis- 74-13 kya; Flores, Indonesia; 400 cc brain; Complex tool use and behavior/ Naledi- 335-236 kya; South Africa; Australopithecine like in brain size and body shape, but also similar to humans in many ways
Homo Traits
More rounded braincase
Reduced post-orbital constriction
Reduced lower facial prognathism
Narrower tooth crowns
Reduction in length of molar tooth row
Parabolic dental arcade
Ergaster/ Erectus Key Trait
Large brain; Brow ridge; Occipital torus (point at the back of the head)
Dispersal out of Africa
Homo Ergaster found in Georgia; 1.8 myo/ Homo Heidelbergensis found in Europe and Asia; 800-200 kya
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