Human Prehistory exam 2 Flashcards
Which processes of evolution shuffle alles
Natural Selection, Gene drift, and Gene flow
Which processes of evolution creates alles
Mutation
Directional Selection
Goes to one extreme
Stabilizing Selection
Goes for an average scale
Disruptive Selection
Goes for both extremes
No Selection
Nothing major happens
Lactose tolerance in adult humans
Resulted from random mutations
C/C: Lactose intolerant C/T: Tolerant T/T: Tolerant
Sickle cell Anemia
Resulted from cultures moving from one place to another and changing the environment, interacting with malaria, natural selection, and random mutation
A/A: No sickle cell (risk of death to malaria), A/S: Sickle cell (low risk of death), S/S: Too much sickle cell (?)
Trisomy
A genetic disorder in which a person has three copies of a chromosome instead of two
Klinefelter Syndrome
Where boys and men are born with an extra X chromosome
Chromosomal Mutation
These mutations can involve deletions, insertions, inversions, or translocations of sections or segments of DNA
Barriers to gene flow
Rivers, mountains, islands, canyons
Exogamous
More flow, more genetic variation (reproducing outside the group)
Endogamous
Less flow, less genetic variation (reproducing inside the group only)
Patrilocal
Males stay in birthplace; females migrate
Matrilocal
Females stay in birthplace; males migrate
Founder effect
Small group leaving a big group, settling elsewhere, and becoming isolated
Blood types
A, B, AB, and O
The Race concept
Using the physical differences between people as a value system (one is more superior to the other).
It’s typically used to justify discrimination against others.
With our advances in understanding DNA, the race concept has become irrational and irrelevant.
Typological classification
5 races
Franz Boas
Debunked “head shape based on race” theory
R.C Lewontin
Genetic variation does not follow racial categorization
The idea of Clines
Gradual changes in variation overtime
4 levels of adaptations
Genetic (Natural Selection)
Developmental (Ontogenetic)
Acclimatization (Physiological)
Cultural (Behavioral)
Bergmann’s and Allen’s rules: Body Shape
Heat stress: vasodilation, sweating and hairlessness, tall and skinny
Cold stress: vasoconstriction, shivering (it warms you), Elevated BMR (Faster metabolism), clothes and shelter, short and round
Vasodilation
Blood vessels expand
Vasoconstriction
Blood vessels constricting themselves
Characteristics of skin pigmentation
Structure of skin, structure of pigment production, UV radiation, melanin content
Pros and cons of UV Radiation
Pros - We make vitamin D from it
Cons - Too much UV radiation can lead to skin cancer
Why study primates?
So we can understand ourselves as a species since they are our closest relatives
Characteristics of primates
Arboreal, highly social, generalized teeth, grasping hands and feet, opposable first digits, nails instead of claws, forward-facing eyes, stereoscopic vision, enclosed bony orbits, mainly diurnal, single offspring (k-selected), longer period of maturation, greater dependance on learned behavior, large brains
Strepsirhines
- Lemurs, Lorises, and Galages
- Nocturnal and diurnal
- Moist rhinarium and > olfaction
- Tooth comb and grooming claw
- A few have litters
Haplorhines
- Dry nose
- Diurnal (two exceptions)
- Very social (one exceptions)
- Large brains
- Longer growth
- Single births (two exceptions)
Tarsiers
- Nocturnal
- Predatory
- Pair-bonded
-Tiny - Carnivore
- “Park” the young (bring your offspring with you or leave it
Platyrrhini
- Nostrals point sideways
- Prehensile tails (grasping tails)
Ceropithecienes
- Fruit and seeds
- Cheek pouches
- Similiar arm and leg lengths
- Short tails
Hominoid
- Apes and Humans
- Increased brain volume and intelligence
- Larger growth period
- Increased social complexity (1 exception)
- Large body size
- Unique locomotor patterns
Y-5 molars
The lower molar teeth of apes and humans have five cusps, or raised points, on their grinding surfaces
How do fossils form?
When an organism dies, if they get covered in sediment, they will be under the right conditions to fossilize
Trace fossils
Fossils of footprints
How do we date fossils?
We examine in a lab and look at how many half-lives are left in the fossil. Additionally, you can also look at the rock layer in which it came from.
