Lecture 6

Question 1

Be able to define evolution in terms of allele frequencies

Answer 1

Evolution is the change of shift in gene variations that shapes characteristics and traits within a population. With Allele frequency it is driven by natural selection, mutation, and genetic drift

Question 2

Understand both meanings of “adaptation”

Question 3

Why do we not talk about evolution as a process of overall “improvement?

Answer 3

because it is driven by adaptation to specific environments rather than a linear progression toward perfection, and what is considered advantageous can vary in different ecological contexts.

Question 4

Be able to explain how natural selection works, in terms of both alleles and
phenotypes. How are limitations in natural resources important?

Answer 4

Natural selection, acting on phenotypes, favors individuals with advantageous alleles for survival and reproduction, with limitations in natural resources serving as crucial selective pressures that shape the evolution of populations.

Question 5

What did Gregor Mendel discover about inheritance?

Answer 5

by studying the patterns of trait transmission in pea plants, laying the foundation for the field of genetics.

Question 6

explain the New Synthesis (Neodarwinism) and how it made natural
selection a well-accepted idea

Answer 6

explained how genetic variation and natural selection work together to drive evolutionary processes, leading to the widespread acceptance of natural selection as a central mechanism in evolution.

Question 7

What are some examples of microevolution that have had a direct impact on
human welfare? For example, how has microevolution through selection
impacted mosquito and bacteria populations?

Answer 7

Microevolution: minor changes in populations over short time intervals

Question 8

What is the difference between anagenesis and cladogenesis?

Answer 8

Anagenesis: The entire species evolves into a new one( the number of species doesn’t change)

Cladogensis: a new species evolves from a population( the number of species increases)

Question 9

For cladogenesis, what is the difference between allopatric and sympatric
speciation? Which of these is thought to be more common, and why? Explain
in terms of the Founder Effect and peripherally isolated populations.

Answer 9

most cladogenesis are probably allopatric
-founder effect: a small population will have less genetic diversity so small populations will have more homozygotes.
-isolated populations contribute to allopatric because it experiences reduced gene flow and lead to divergence