Sexual Selection Flashcards
1
Q
Define “Sexual dimorphism”
A
How males and females look different, with males usually being more ornamented
2
Q
What is Bateman’s Principle?
A
- Variance in reproductive success is greater in males than in females
- Variance is a consequence of heterogamy (fusion of 2 dissimilar gametes)
- Females invest more in offspring
- Females value resources more and males invest in competing for females
3
Q
Females are limited by….
Males are limited by…
A
How many offspring they can birth
How many females they can impregnate
4
Q
What is Fisher’s Runaway Selection hypothesis?
A
Females who mate with attractive males have attractive sons. The preference and the trait becomes magnified over time
5
Q
What is Zahvi’s ‘Handicap’ hypothesis?
A
Exaggerated secondary sexual traits are an honest indictator of good genes. The individual has to be strong enough to overcome the handicap e.g. a peacock must be able to carry its feathers
