Module 8 Flashcards
1
Q
Determinate growth
A
- Mammals like humans have distinct life phase that is devoted to growing to adult size, and then growth stops
- During this time, energy is not spent on reproduction
2
Q
Age of Maturity
A
- Childhood Strategy ~ Growth and Maintenance - Adult Strategy ~ Reproduction and Maintenance - This transition is assumed to optimize the BENEFITS of growth larger versus the COST of delaying reproduction
3
Q
How does decreased energy availability affect growth?
A
- Later age of maturity (slow) - or - smaller adult body size (stop earlier) - or - Both
4
Q
What happens with an increase of energy and growth during childhood?
A
When the body has an intake of energy and growth and finally hit the stopping point they tend to develop sexual maturity earlier in life.
5
Q
Two major Hypothesis for Transition from Growth to Reproduction (Age of Menarche) in Females
A
- Critical Fat Hypothesis
- Skeletal Maturation Hypothesis
6
Q
Critical Fat Hypothesis
A
- Menarche occurs when sufficient body fat has been accumulated
~ Fat is necessary to reproduce - Menarcheal age has reduced in accordance with increasing BMI in populations
- Underweight girls have late menarche
- However, there is only a weak relationship between age and weight (or BMI) at the time of menarche
- Often, being obese delays menarche!
7
Q
Skeletal Maturation Hypothesis
A
- Manarche is delayed until the pelvis is large enough to support a live birth
- If the pelvic canal is not big enough to accommodate the infant brain, mother and infant can die during childbirth
- Constraint that is unique to humans - Big Brains + bipedal-ism ?
8
Q
In girls
A
- Reproductive ability occurs after growth spurt and appearance of secondary sexual characteristics
9
Q
In boys
A
- Reproductive ability occurs before growth spurt and appearance of secondary sexual characteristics
10
Q
Stages of Human development
A
- Embryo/ fetus ~ birth - Infancy ~ weaning - Juvenility ~ Onset of puberty - Adolescence ~ completion of social and physical development (puberty) - Adulthood ~ senescence - Old age
11
Q
Juveniles
A
- can often survive without their mother, but require support from others
12
Q
Long juvenile periods
A
- Are rear but found in highly social animals (primates, whales, lions, hyenas, elephants, etc.)
13
Q
We cannot afford the cost of grow up faster
A
- Cost of brain growth constrains body growth
- MOthers divide thier efforts by investing by multiple offspring
14
Q
Ecological risk aversion
A
- If the environment is unpredictable, spreading growth over a long time minimizes the risk of starvation
15
Q
Slow development is necessary for learning the skills to be an adult
A
- social learing hypothesis
~ need to learn social skills and develop alliances - learning to forage
