36-Sibling Rivalry

Question 1

Why is there sibling rivalry?

Answer 1

Space and resources for young can be limited

Question 2

What forms does it take in sharks, antelope, pigs, and hyenas?

Answer 2

Sharks-cannibalism. Antelope-kill the other. Pigs slap each other to get the favored teat of mother (anterior teat gets more milk). Two hyena neonates per birth, kept in burrow, but only one emerges, especially if both males.

Question 3

What form does it take in Dalbergia sissoo?

Answer 3

Pods are wind dispersed. Most pods only have one seed, but start out with multiple. They use chemical siblicide to extract from good embryo, which kills younger embryos. Single seeds get the advantage of being airborne for longer/goes further from tree.

Question 4

What do observational and experimental studies with birds indicate about the selective background of siblicidal behavior?

Answer 4

That killing a sibling may benefit both the surviving offspring and the parents. Ex. Parent bird brings a big fish back for chicks, but they cant eat it because its too big. So they commit siblicide and then parents start bringing small fish.

Question 5

What is the evidence for sibling rivalry in humans?

Answer 5

First borns tend to be more conservativ/religious than later borns