Exam 3: Primate Reproductive Patterns

Question 1

Life history

Answer 1

• A theory that explains the patterns and timing of key life events such as birth, puberty, reproduction, and life span within the context of natural selection
• Asking a timing of key life events
• All mammals aren’t the same
• How long going through puberty
• Traits vary among mammals, between mammals and primates and even among primates
• Varies greatly

Question 2

Age at first reproduction (puberty)/average lifespan

Answer 2

• Body weight and phylogeny are important factors in understanding life history patterns
• The larger the body mass the older the mammal goes through puberty
• RElationship between adult mass
• -Smaller body size means going through puberty at an earlier age
• Primates as a baseline have a later age in starting puberty compared to mammals of similar body size
• Average lifespan for smaller body size is its shorter like a mouse
• -Predation causes a shorter life span
• Bigger animals have longer life spans
• Mouse lemurs have a longer life span even though its the same size as a mouse
• Compared to other mammals of similar size, primates are “slower”. They go through puberty later and they live longer

Question 3

Comparing Norwegian rat and galago primate

Answer 3

• Same body size but the galago lives longer, goes through puberty later, gestation is longer, and lower litter size
• Even though they are a small mammal, galagos have a slow life history like other primates. Phylogeny matters.

Question 4

Primates also vary in life history traits

Answer 4

• The mouse lemur and the gorilla
• Mouse lemur is smaller than the gorillas
• Predation is an indicator of needing more babies so mouse lemurs have more offspring
• It takes more work to produce a gorilla baby than a mouse lemur
• Mouse lemur’s life history is fast compared to the gorilla
• -Mouse lemurs are smaller with a shorter lifespan is the why

Question 5

Humans also differ from other primates in some life history patterns

Answer 5

• Human infants and juveniles are dependent on mother for a longer time than most other primates
• Infants are very dependent on us and don’t grow very fast
• Humans live a lot longer
• Body size affects average life span
• Strepserhinne primates only reproduce for as long as they live
• Humans go through menopause and contain to live past that point
• Human females have a longer post-reproductive period and all go through menopause

Question 6

Menopause is not a part of the life history of other primates

Answer 6

• Weird thing that we do
• It’s a species specific trait
• Pilot whale/killer whales are the other mammals that go through something similar to menopause
• What could account for menopause in humans females?
• -Culture, body size, etc.
• -The human reproductive system may have adapted to a much shorter life span than modern humans
• -Cultural buffering allowing humans longer than we were meant to
• Female reproductive capacity declines more rapidly than other physiological functions

Question 7

Good mother/grandmother hypothesis

Answer 7

• Older individuals tend to do a lot of childcare
• Evolutionary hypothesis
• Natural selection at work
• Menopause may have been favored by natural selection if postmenopausal women could better increase the survival and reproduction of either their existing children or their daughters offspring
• Grandmother help mothers and grandmothers reproduce and to raise offspring
• Putting energy to raise related children
• Increase survival of daughters offspring