Development (L20) Flashcards
What is the uncertain futures problem
environmental risk/uncertainty
> selects for phenotypic plasticity
define phenotypic plasticity
: The ability of an organism to change its phenotype in response to changes in the environment
explain selection for phenotypic plasticity in short lifespan organsims
o Short lifespan= selection for phenotypic plasticity lower // not necessary
why is body not grown proportionally, i.e. brain faster
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
explain energy allocated associated with fast/slow growth rates
-Growing faster= allocating more energy to process than slower growth
o Deceleration early > brain growing tho (energy allocated preferentially to brain)
describe sex variation in developmental pathway
• Girls hit growth spurt > plateau (stop in growth coincide with reproduction)
what does a deviation of growth from standard indicate
enviro factors changes
= malnutrition
factors affecting age at menarche
adoption, health and neutron, psychosocial stress
why might deviation get worse for weight vs age of children
o Something accumulating overtime
o Children buffered at younger at? Breastfeeding?
when can being short be advantage ?
-only in nutrient poor environment
how can being short be advantage ?
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
why are less active children heavier
large body= more energy to maintain // less energy for activity
what is reaction norm
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
explain migration as a change of condition
an improvement of condition
how can early migration differ in affect from later and what does it show
earlier = stronger affect of change in environment
• Critical period for change in resources to have maximum affect
what is a psychosocial effect on menarche
father absence= early menarche
factors that make individual more likely for earlier mearche
• Nutritionally good (as nutrioninal= factor in whether body can handle repro), surrounded by disfunction + sense of risk
relationship bw SES + disease risk
- If parent in lower socio economic environment > likely to have lower birth weight > more likely to have disease
- Intergenerational affect of social environment
2mechanisms as why increase risk w. low birth weight
- 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
- Delayed cost for surviving in utero
how can plasticity be not adaptive
- 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 - Environment changes
• Predictive adaptive trajectory no longer matches current circumstance
• E.g. rapid catch up growth
