Sexual selection Flashcards
What does isogamy mean
Same size gametes
What are the two strategies for gamete production
One big gamete or lots of smaller gametes
What is zygote size determined by
The sum of gametes that fuse to form them
What are smaller gametes useful for
They maximise the chances of reproducing with other gametes
What are larger gametes useful for
They guarantee zygotes with higher fitness
Whats the disruptive selection of gamete size
Acts against medium sized gametes
What does anisogamy mean
Males and females produce different sized gametes
How do males increase their fitness
Mating with as many females a possible
Whats the bateman principle
Variance leads to competition in males
What does female choosiness involve
Direct benifits that mates can bring such as resources, food, nest sites etc.
Direct benefits example 1
Mottled sculpin, males fertilise eggs and defend them. There was a positive correlation between length and size of male and eggs in territory
What does fertililty mean
ability to produce offspring
What does fecundity mean
Potential number of offspring that could be produced
Direct benefits example 2
Female scorpinflies swap copulations for nuptial gifts, females get nutritional benefits
What is the fisherian runaway sexual selection model
Females choose males that are attractive because they produce attractive sons so traits become more and more exaggerated.
Example: Molly Schumer, sword fish tail, elongated fin
