Ecology Chapter 7 & 8 Flashcards
Define Life History
sequence of events or landmarks related to an individuals growth, survivorship and reproduction
What does life history include?
size at birth growth rate age and size at maturity age specific reproductive effort number and size of offspring mode of reproduction (sexual vs asexual
interparous
reproduces multiple times in the organisms life
semelparous
reproduce once than dies ex. glow worms, salmon
protandry
protandrous -organism transforms from male to female
protogyny
protogynous- organism transforms from female to male
anisogamy
not same gamette
isoganous
o+
o-
alternation of generations
term used to describe life cycle of plants and other organisms that alternate between a multi cellular haploid stage (AKA gametophyte) and a multicellular diploid stage (AKA sarophyte)
sporophyte
multicellular 2N stage
Complex life cycles
composed of atleast two distinct stages that differ in their habitat physiology or morphology
complex life styles are common…
by absolute numbers, they are not the exception
why have complex life cycles
- different stages experience the environment differently
2. reduced or no competition between parents and offspring
life history continua
r vs k selected species
r selected species
“weedy” species with high population growth rate - “Live fast, die young”
k-selected species
longer lived, slow growing, good competitors
infanticide
form of male to male competition
lion killing cubs to speed up female lions return to being able to concieve
proximate behavior
immediate mechanistic reason why behavior occurs
ultimate behavior
evolutionary and historical reasons why behavior occurs
MacArthur and Planka coined what theory?
Optimal Foraging theory
Optimal foraging theory main assumption
natural selection has operated strongly on foraging behavior thus foraging behavior should be adaptive
optimal foraging
species should forage in an efficient manor that maximizes and minimizes cost
varies with species and envir. context
time -cost
calories-benefit
optimal food choice
profitability of a food item (p) depends on how much energy (e) the animal gets from the food relative
marginal value theorem
predicts ‘giving up time’ in a world where food occurs in patches
-as animal forages, the amount of energy gain gradually begins to slow down as food becomes scarcer in the patch
altruism
behavior that appears to benefit others at a cost to the individual preforming the act.
ex. ground squirrels calling out to other squirrels when predator is near putting themselves at a bigger risk to be spotted.
group selection argument
groups containing altruists should have a survival advantages over selfish individuals
kin selection
selection for a behavior that decreases ones own fitness but increases the reproductive fitness of a relative
inclusive fitness
individuals fitness and fitness of a relative = total number if gene copies passed down from one generation to another
Hamilton’s rule
an altruistic gene will be favored by natural selection IF rB > c - cost to altruist
eusociality- (extreme altruism)
- reproductive division of labor (fixed?)
- cooperative care of young
- overlapping generations
reciprical altruism
doing something kind for someone else in hopes of getting something in return from someone else
