Theory (L1-2) Flashcards
4 requirements of NS
variation
heritability
competition
differential reproduction
explain variation (4 NS)
indivs, in pop have diff phenotype, allow one or more trait to be selected for over others
explain heritability (4 NS)
offspring have prob of carrying same trait as parents, allows ‘selected’ trait to be passed on
explain competition (4 NS)
for resources, not all equally successful in acquiring energy
explain differential reproduction (4 NS)
some individuals better able to reproduce, enables change in freq of genotypes
define natural selection
change in frequency of genotypes within a pop over gens due to differences in ability of phenotypes to respond to selection pressures
define principal of allocation
trade offs, resources allocated to one process cannot be used for another
what are the two levels of explanation
proximate: within life time (what or how)
ultimate: fitness related (why)
define reproductive success
number of viable, fertile offspring produced by an individual
define fitness
measure of the contribution to the next generation of one genotype in a population relative to the contributions of other genotypes within the population
explain Fitness in relation to RS
RS relative to the rest of the population
o Fitness= geno/phenotype, RS= individual
define adaption as a verb
trait that enables carrier to be better suited to environ, result in higher fitness and therefor reproductive success against a specific selection pressure
define adaption as a noun
traits that result over the long term (outcomes) of process
how to know if a trait is an adaption
increases fitness
why do pops evolve not species
each pop= own selective pressures due to diff environs, // unlikely all evolving in same way
define differential mortality
o Different populations have different mortality exposure
define differential fertility
children for any individual, but individuals in population differ in number that they produce
3 types of selection
directional, disruptive, stablizing
what does stabilising selection mean
population gets better and better at optimising environment
define altruistic behaviour
a behavior that conveys an individual fitness cost to the actor and a fitness benefit to the recipient
is altruistic individual evolution
- = NOT expected to evolve through natural selection at the individual level
- Imposes fitness cost (// less reproduction value)
what is r
coefficient of relatedness
- proportion of alleles in common due to shared common ancestor
what does hamiltons rule explain
genes with apparent fitness cost can be selected for
what is hamiltons formula
rB > c
