Adaptation 2

Question 1

What are the two sources of adaptation?

Answer 1

1. New mutation
2. Standing genetic variation

Question 2

What is standing genetic variation?

Answer 2

It is variation that was already present in the population being recruited by the environment

Question 3

What example gives empirical evidence of de novo mutation leading to adaptation? How?

Answer 3

E coli was grown in a lab, and separated groups reached fitness at different rates, even when they began at the same genetic state and fitness level

Question 4

The stickle back fish demonstrates what kind of adaptation?

Answer 4

Standing variation

Question 5

Why is standing variation adaptation generally faster acting (more important in rapid change) than de novo mutation?

Answer 5

The population does not need to wait for new mutations

Question 6

What is linkage disequilibrium?

Answer 6

Variants at nearby loci will often be inherited together, causing a statistical variation between alleles at different loci

Question 7

What is the name of the process where alleles with directional selection will carry other alleles along to high frequency?

Answer 7

Selective sweep / genetic hitchhiking

Question 8

What is the name of the consequence of genetic hitchhiking?

Answer 8

Genetic draft

Question 9

What is genetic draft?

Answer 9

The loss of alleles as a consequence of being linked to selective sweep loci

Question 10

What are the two ways scientists can understand the genetics of fitness traits?

Answer 10

1. Quantitative tail locus (QTL) analysis
2. Genome-wide association studies

Question 11

Describe the QTL analysis method?

Answer 11

Cross an F1 and F2 generation, and then score F2 for phenotype and examine the DNA at many loci to look for markers

Question 12

Describe the genome wide association studies (GWAS)

Answer 12

SNPs are compared in order to attempt to find variants at points of interest

Question 13

Are the results of QTL and GWAS the alleles that influence the trait?

Answer 13

No, they could just be variants in loci close to the gene of interest