Development (L20)

Question 1

What is the uncertain futures problem

Answer 1

environmental risk/uncertainty

> selects for phenotypic plasticity

Question 2

define phenotypic plasticity

Answer 2

: The ability of an organism to change its phenotype in response to changes in the environment

Question 3

explain selection for phenotypic plasticity in short lifespan organsims

Answer 3

o Short lifespan= selection for phenotypic plasticity lower // not necessary

Question 4

why is body not grown proportionally, i.e. brain faster

Answer 4

Systems mature at different rate
o Pattern of growth result of natural selection
• Some need earlier development= (i.e. brain) needs more rapid
• Reproduction not needed till later

Question 5

explain energy allocated associated with fast/slow growth rates

Answer 5

-Growing faster= allocating more energy to process than slower growth
o Deceleration early > brain growing tho (energy allocated preferentially to brain)

Question 6

describe sex variation in developmental pathway

Answer 6

• Girls hit growth spurt > plateau (stop in growth coincide with reproduction)

Question 7

what does a deviation of growth from standard indicate

Answer 7

enviro factors changes

= malnutrition

Question 8

factors affecting age at menarche

Answer 8

adoption, health and neutron, psychosocial stress

Question 9

why might deviation get worse for weight vs age of children

Answer 9

o Something accumulating overtime

o Children buffered at younger at? Breastfeeding?

Question 10

when can being short be advantage ?

Answer 10

-only in nutrient poor environment

Question 11

how can being short be advantage ?

Answer 11

o Maintenance more expensive (higher cost of simply living)
o Maintenance cannot change
o // shorter can be somewhat adaptive if consistently exposed to low calorie environment
• Can allocate more energy to repro and maint

Question 12

why are less active children heavier

Answer 12

large body= more energy to maintain // less energy for activity

Question 13

what is reaction norm

Answer 13

Pattern of phenotypic expression of a single genotype across a range of environment
• Difference b/w=reaction norm (how much can a phenotype vary depending on particular condition

Question 14

explain migration as a change of condition

Answer 14

an improvement of condition

Question 15

how can early migration differ in affect from later and what does it show

Answer 15

earlier = stronger affect of change in environment

• Critical period for change in resources to have maximum affect

Question 16

what is a psychosocial effect on menarche

Answer 16

father absence= early menarche

Question 17

factors that make individual more likely for earlier mearche

Answer 17

• Nutritionally good (as nutrioninal= factor in whether body can handle repro), surrounded by disfunction + sense of risk

Question 18

relationship bw SES + disease risk

Answer 18

• If parent in lower socio economic environment > likely to have lower birth weight > more likely to have disease
• Intergenerational affect of social environment

Question 19

2mechanisms as why increase risk w. low birth weight

Answer 19

1. Adaptive Mechanism
   • If in utero has low conditions= body predicts this in birth
   • but when enviro during birth= better than prepared for > rapid catch up

OR

2. Delayed cost for surviving in utero

Question 20

how can plasticity be not adaptive

Answer 20

1. Most important thing= survival (in short term)
   • // small birth rate = to cope with short resources
   • But is it instead current resources + not at all predictive
2. Environment changes
   • Predictive adaptive trajectory no longer matches current circumstance
   • E.g. rapid catch up growth