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GG Chapt 2
Study
1
Question
What does an F<sub>ST</sub> value exceeding 0.25 indicate?
Answer
Presence of subspecies or biological races
2
Question
What is the primary source of genetic variation among humans?
Answer
Mutations in DNA
3
Question
What is a copy number variant (CNV)?
Answer
Duplications, deletions, insertions, inversions in the genome
4
Question
What is the significance of the human F<sub>ST</sub> value about 0.15?
Answer
Low genetic differentiation across populations
5
Question
What does the 'founder effect' cause in migrating populations?
Answer
Reduction in genetic variation
6
Question
How does gene flow influence human genetic differentiation?
Answer
Reduces differentiation by continual interbreeding
7
Question
What evolutionary process leads to the fixation of beneficial mutations?
Answer
Natural selection based on fitness
8
Question
What is one example of a simple genetic basis for adaptation in humans?
Answer
Hemoglobin mutation conferring malaria resistance
9
Question
How does distance from Africa relate to human genetic diversity?
Answer
Genetic diversity declines with distance from Africa
10
Question
What does a high F<sub>ST</sub> value (e.g., 0.351) suggest about populations?
Answer
Strong genetic differentiation, possibly subspecies
11
Question
What role does natural selection play in human adaptation?
Answer
Favoring beneficial variants for local environments
12
Question
What is continuous variation in human genetics?
Answer
Gradual change in traits across geographic regions
13
Question
How do mutations contribute to adaptations like skin color variation?
Answer
Different allele frequencies shaped by natural selection
14
Question
What does pleiotropy mean in genetics?
Answer
One gene influences multiple traits
15
Question
What is an example of positive pleiotropy in human adaptation?
Answer
Genes for Arctic survival also promote heat retention
16
Question
What is the significance of the 'selective sweep' as shown in Figure 2.2?
Answer
Rapid increase in a beneficial mutation's frequency
17
Question
How do environmental changes influence human genetic adaptations?
Answer
Select for variants suited to new environments
18
Question
What is the impact of the Pleistocene climate fluctuations on human evolution?
Answer
Moved populations, created bottlenecks, and promoted local adaptations
19
Question
How does pleiotropy explain high-altitude adaptation in Tibetans?
Answer
One gene affects multiple traits beneficial for altitude.
20
Question
What is an example of negative pleiotropy affecting human health?
Answer
Genes causing cancer at later ages.
21
Question
What evidence suggests humans hybridized with archaic species?
Answer
Modern humans carry 1-2% genes from archaics.
22
Question
How do social definitions of race differ from biological reality?
Answer
Social categories are culturally contingent and unstable.
23
Question
What does an F<sub>ST</sub> value over 0.25 suggest?
Answer
Presence of subspecies or significant genetic divergence
24
Question
What is the primary source of genetic variation in humans?
Answer
Mutations in DNA sequences
25
Question
What is a copy number variant (CNV)?
Answer
Genomic structural variation involving duplications, deletions, insertions, and inversions
26
Question
How does human genetic variation compare to other mammals?
Answer
Humans have less variation, with F<sub>ST</sub> around 0.15
27
Question
What does a low F<sub>ST</sub> around 0.15 indicate about human populations?
Answer
Minimal genetic differentiation, high gene flow
28
Question
Why do humans lack deep genetic races?
Answer
Continual gene flow and recent common ancestry reduce differentiation
29
Question
What explains continuous genetic variation across regions?
Answer
Isolation by distance
30
Question
What effect does the founder effect have during migration?
Answer
Reduces genetic diversity in new populations