Topic 1: History

Question 1

what use is population genetics?

Answer 1

• uses knowledge of the rules of inheritance to predict (using math) how the genetic composition if a population will change under the forces of evolution and compares the predictions to relevant data

Question 2

what are some of the aspects of science that population genetics arose from?

Answer 2

• darwinism
• modern synthesis (neo-darwinism)
• integrated synthesis

Question 3

what are gradualists? saltationists?

Answer 3

Gradualists: believe that selection acts on small individual variations - evolution is slow

Salvationists: believe that selection must act on large and discontinuous traits- evolution is mostly stasis with occasional jumps

Question 4

What are the 3 key aspects of modern synthesis:

Answer 4

1. New variation occurs thru mutation
2. inheritance happens thru DNA
3. Natural selection happens thru adaptation

Question 5

what is FIsher’s fundamental theorem of natural selection?

Answer 5

• the rate of increase in mean fitness is a product of the variance in fitness
• if being larger is only slightly more advantageous, the rate of variance to evolve to a larger size will be low
• if being larger is very advantageous, the rate of variation will be fast.

Question 6

Data is separated into 2 categories….

Answer 6

• qualitative (descriptive)
• quantitively (numbers)

Question 7

quantitive data is separated into 2 categories….

Answer 7

• discrete (defined categories)
• continuous (scales, decimals)

Question 8

What is a parameter?

Answer 8

• a characteristic of a population
• a constant in the equation, how it changes over time)

Question 9

what is an event?

Answer 9

an outcome of an event, result of an observation

Question 10

what is frequency? relative frequency?

Answer 10

frequency: the number of times the event occurs

relative: the number of times it occurs divided by the number of time the experiment was performed

Question 11

What is population genetics?

Answer 11

the study of the processes that regulate changes in gene frequency

Question 12

Are the terms ‘dominant’ and ‘recessive’ connected at all to the frequency of an allele?

Answer 12

• No!
• Dominant traits will not increase in frequency, even if we ‘see’ more of them in the population. This is expression.
• Hardy-Weinberg equilibrium was created to determine why dominant traits aren’t more frequent in a population

Question 13

What are quantitative traits?

Answer 13

A quantitative trait is one that can be measured numerically, such as height.

Question 14

How do we define ‘population’ in the field of population genetics?

Answer 14

a group with a common gene pool from which individuals choose mates with whom they reproduce

Question 15

Who are the three main individuals associated with the synthetic theory of evolution?

Answer 15

Mendel, Galton, and Darwin

Question 16

Theodosius Dobzhansky wrote the book ‘Genetics and the Origin of Species.’ Who was Dobzhansky and why
was this book important? Summarize the first chapter in a paragraph.

Answer 16

• Dobzhansky was a biologist from 1900-1975. Major person in the field of genetics and evolutionary biology, shaped modern synthesis
• the first chapter of his book gives a broad introduction to population genetics, where the founding science comes from (darwin, mendel), and reinforces the scientific concepts of evolution and genetics.
• His book popularized population genetics, and influenced the genetic aspect of evolution
• combined empirical data with mathematical models

Question 17

How does Dobzhansky define discontinuity? Give an example illustrating discontinuity. Include mention of
Figure 1 from Chapter 1.

Answer 17

• Dobzhansky defines discontinuity as variation between organisms, and how if we look at all living organisms living, there is no continuous distribution between different species, rather we have separate distributions
• disconnections in traits! breaks between topographic peaks are the discontinuity
• ex. cats and lions
• figure one relates to this concept, as as species become more distinct from one another, and have more discontinuity, the further away they exist on the topographic map