Topic 1

Question 1

What leads to evolution?

Answer 1

changes in the allele frequency from one generation to the next, at a molecular level

Question 2

What is population genetics?

Answer 2

study of the processes that regulate these changes in gene frequency

Question 3

What are theoretical population genetics

Answer 3

uses mathematics and computer models to understand the effects of different purposes

Question 3

What are theoretical population genetics

Answer 3

uses mathematics and computer models to understand the effects of different purposes

Question 4

What are experimental population genetics

Answer 4

uses controlled laboratory and field experiments to test theoretical predictions

Question 5

What are empirical population population genetics

Answer 5

studies genetic variation in natural populations often with the aim of understanding population biology

Question 6

What are Darwin’s four postulates of Evolution via Natural Selection?

Answer 6

1. More individuals are born than survive
2. Individuals vary
3. Some variation is inherited
4. Survival and reproduction is not random

Question 7

How can a population diverge over time?

Answer 7

accumulation of advantageous variations

Question 8

What are gradualists

Answer 8

believes that selection acts on small individual variations and therefore evolution is slow and gradual

Question 9

What are saltationists

Answer 9

believed that selection must act on large discontinuous traits and therefore evolution is mostly stasis with occasional jumps

Question 10

What was discovered after the rediscovery of Mendel’s work?

Answer 10

• showed that inheritance was due to the passing on of discrete hereditary units
• saltationists felt that this supported their view of evolution by discrete steps
• gradualists felt that this was inconsistent with their experiments on continuous traits and the process of gradual evolution

Question 11

What did Hardy and Weinberg discover

Answer 11

showed that allele frequencies and genotype frequencies remain constant in the absence of perturbation

Question 12

What did R.A. Fisher discover

Answer 12

• variation in quantitative characters could be explained by Mendelian inheritance
• developed important statistical techniques and developed quantitative genetics
• Fundamental Theory: more genetic variation that exists, more selective pressure that it can adapt to

Question 13

What were contributions of JBS Haldane?

Answer 13

developed mathematical theory of natural selection and pioneered mathematical predictions of the changes in gene frequency due to selection

Question 14

What was Sewall Wright known for?

Answer 14

• known for his work on inbreeding and effective population size
• Wright emphasized evolution through genetic drift in small populations
• Shifting balance theory describes evolution as a process by which favourable gene combinations come together then increase in frequency by selection

Question 15

How did Theodosius Dobzhansky contribute to population genetics

Answer 15

• used empirical date from natural and experimental Drosophila supported the theoretical work of Fisher, Wright and Haldane
• argued that mutation is the source of all variation

Question 16

What technique was discovered in 1966?

Answer 16

molecular population genetics was pioneered when Lewontin & Hubby both published the technique of protein electrophoresis - to study how much variation is in a population

Question 17

What is the neutral theory of molecular evolution

Answer 17

• most variation at the protein level is neutral
• variation is maintained by a balance between mutation and genetic drift
• controversial idea, leading to “selectionist” versus “neutralist”

Question 18

How did Tomoko Ohta change Kimura neutral theory?

Answer 18

• discovered that new mutations were slightly more deleterious rather than neutral
• called the nearly neutral theory

Question 19

What changes occurred after the 1980s

Answer 19

• restriction enzymes allowed for DNA sequence variation to be studied directly
• DNA sequencing revealed even mor variation than what had been found at the protein level
• Polymerase Chain Reaction (PCR) made it easy to compare many individuals and many genes using molecular genetic markers
• advances in technology now makes the sequencing of entire genomes routine