Lecture 9

Question 1

Reasons for Sexual Selection

Answer 1

• eggs are more energetic than sperm and more costly to produce, resulting in the females investing more in the offspring
• should be stronger in males because they have to compete for female

Question 2

Female Choice

Answer 2

females choose mates on the basis of

1. physical characteristics that signal male genetic quality
2. resources or parental care provided by males

Question 3

Male-Male competition

Answer 3

females have no choice, males compete for the female

Question 4

Honest Advertising Example

Answer 4

beak color of male zebra finches is more colorful based on nutrition, and females prefer colourful beaks

Question 5

Example of Nuptial Gifts

Answer 5

preying mantis’ mate and the female eates the male to get nutrition for the offspring

Question 6

example of Sensory Exploitation

Answer 6

-male spiders have furry legs which females like, pre existing bias that females like furry legs

Question 7

Species

Answer 7

evolutionarily independent population of group of populations

Question 8

Biological Species Concept

Answer 8

• assigns individuals to the same species if the actually or potentially interbreed
• populations are evolutionarily independent if they are reproductively isolated

Question 9

Prezygotic mechanisms of reproductive isolation

Answer 9

temporal: breed at different times
habitat: bred in different habitats
behavioural: courtship displays differ
gametic barrier: eggs and sperm are incompatible
mechanical: male and female genitalia is incompatible

Question 10

Mechanisms of reproductive isolation: Post zygotic

Answer 10

Hybrid Viability: hybrids die as embryos

Hybrid Sterility: offspring mature by are sterile as adults

Question 11

Prezygotic Isolation

Answer 11

individuals of different species are prevented from mating

Question 12

Post zygotic Isolation

Answer 12

individuals from different populations do mate, but the hybrid offspring produced either have low fitness/sterility or don’t survive

Question 13

Morphospecies Concept

Answer 13

species are distinguished by differences in size, shape, or other morphological features
-based on the idea that distinguishing features are most likely to arise if evolutionary lineages do not have gene flow

Question 14

Phylogenetic Species Concept

Answer 14

-based on reconstructing the evolutionary history of populations

Question 15

Monophyletic group

Answer 15

group of organisms that contain all of the descendants of their most recent ancestor