life history Flashcards
ontogenenisi definition
individual development in life course
life history theory
understanding compromises about schedule of reproductive efforts/tradeoffs between:
- surival + reproduction
- growth + reproduction
c. parental investment and number of offspring
stages of development
infancy (nursing, weaning)
juvenile (social learning, puverty)
sub adult (sexual maturity; decision to disperse or be philopatrous)
adult (breeding and rearing)
senescience (menopause and post reproductive lfie)
variables of developmetn
- fixed length (gestation)
2. snesitive to uprgining of others
type sof babies
precorcial
altricial
precorial
‘advanced state’; born already with some abilities
altricial
‘helpless state’; born underdevelopment
two nursing types:
1. on demand and on schedule
types of nursing
on demand
on schedule
on demand nursing? (+ milk type)
- -> ‘altricial carried babies’
- gain ENERGY from body heat/conserve because are carried by mom
thus: milk…
high protein= growth + development
on schedule nursing?
+ milk type
—> ‘altridical parked babies’; left in one location (nest) and mothe comes/goes
thus. .. milk..
- - high FAT to keep babies warm
precorcial running babies? (milk type?)
high sugar= keep up with the mom (elephants)
examples of ‘on demand’ baby
chimp
examples of ‘on scheduls’ baby
tarsiers, tree shrews
what does rearing style affect in moms
the milk composition
lactational ammenorrhea
prolactine hormone hampers ovulation= makes females setrile post-partum
where does lactational ammenorrhea not occur?
callitrichids
weaning conflict theory : what and by who?
Trivers:
mother= wants to stop nursing but infant wants to conitinue= creates conflict
- ‘parental offspring conflict’ +
- ‘sivling jealously’; older siblings may become ‘helpless’ to gain attention after second baby is born
sex son hypothesis
infant fathers seen as stron gso females have incentive to mate with them despite infancticide
hrdy theory of why males infanticide occurs
speed up lactational ammehnorea to allow for incoming male to mate with female faster (speed up infanticide)
example of infanticide
hanuman indian langur monkeys
where does maternal infanticide occur?
tamarins
humans
R-Selection is…
fast breeding
unstable environment= fluctuating population densities
seasonal patterns of population explosion/breakdowns
K-Selection…
slow breeding
stable environment= leads to stable population deensity
non-seasonale or provisioned environments= efficent food/safety use
Pianka 1970 Formula
R= population growth determined by intrinstic rate of increase of psecies (r) {age, litter size, etc]
K=population desntiy defined by exterinsic carrying capacity of envrionment (plateau of individuals per space that fit into the environment)
are primates k or r selected?
tendency towards K selection as focus on QUALITY and not QUANTITY
r-selected primate?
lemurs
R-selection:
- adult body
- paternal investment
- gestation
- lactation length
- sexual maturity
- longetivity
small bodies quanitty (low paternal investment) short gestation short lacation early sexual maturity short longetivity
R; Selection Nenotates:
- litter size
- skin
- ears/eyes
- mobility
- brain
- shelter type
tend to be altricial
large litters naked skin sealed eyes/ears low mobility small brains in nests (parked babies)
K= Selection
- adult body
- paternal investment
- gestation
- lactation length
- sexual maturity
- longetivity
large adult bodies 'quality' paternity investment long gestation long lactation late sexual maruity long longetivity
K Selection Nenotates:
- litter size
- skin
- ears/eyes
- mobility
- brain
- shelter type
tend to be precorical
small litters furred skin open eyes high mobility large brain no shelter
r + k relative?
oysters; millions of offspring (are R strategiest compared to primates)
primates: prosimians are r-strategiest compare to apes
humans; west africans are r-strategiest compaed to europeans
primary sex ratio vs secondary sex ratio
primary= at conception secondar= at birth
