population ecology Flashcards
What is the equation fro population growth?
pop. growth = mean survival + mean recruitment
What is eco-evolution?
Population growth rate and phenotypic trait, change together
Why dont allele frequencies change forever?
Stabilising selection and Frequency- dependant selection
Response to environmental perturbation such as removing predator?
Phenotypic plasticity through developmental pathways = fast response
+ change in pop. size as diff. limiting factor
What 3 strategies does evolution maximise?
Detection, Acquisition (behaviour + morphology) and Utilisation (opt. life history)
What are 4 effects of removing predators of trinidian guppies?
larger, different diet and mouth shape, slower growing, MORE AGRESSIVE
What is a dispersal assumption made by most population studies?
That dispersal to and from population is negligable
Logic behind population genetics?
Which alleles and genotypes has highest mean fitness
Logic behind life history evolution
Which life history has highest mean fitness
What is the continuous time logistic equation ?
dN/dt = rN ((K-N)/K)
What is the discrete time logistic equation?
N(t+1)= meanS(t) + mean R(t)
OR
N(t+1) = Nt + rNt(K-Nt)/K
What is the logistic equation good at showing?
how Density-dependance can generate a range of population dynamics patterns
Why is logistic equation no good at showing population dynamics in the field?
As birth and death rates fluctuate AND carrying capacity flucutates
How is sea otter spatial and temporal diet variation analysed?
Analyse chemical composition of hair (basal to proximal)
What is predicted to happen in population separated in space but not climate?
Similar pop. dynamics- not perfect e.g. species variation
What factor can increase synchrony between populations?
Dispersal
What is a metapopulation?
a group of spatially separated populations of the same species which interact at some level.
What is the equation of Levin’s metapopulation model?
dn/dt = cn (1-n) - en
= change in fraction of occupied patches with time
What are 4 considerations in Levin’s metapopulation model?
1- patch size variation
2- distance between patches variation
3- diff. pop. dynamics in diff. patches
4- env. variation across patches
What are the 3 vital rates of life hisotry?
survival, development and reproduction
What is iteroparous fecundity?
reach sexual maturity earlier and reproduce multiple times
What is Semelparous fecudity?
BIG BANG- reproduce loads at once
What are the 2 types of matrix population models?
Leslie (age) and Lefkovitch (stage or size)
What are the 2 methods for calculating population growth rate?
1- brute force method- chain rule
2- analystical solution- dominant eigenvalue
