Final (Part 2) Flashcards
what is a population
group of individuals of single species living in same area that interbreed
what is effective population size
theoretical population size with the same level of heterozygosity of large population (if everyone could reproduce)
exponential population growth equation
dN/dt=rN
3 levels of biodiversity
genetic, species, ecosystem
what are biodiversity hot spots
relatively small areas containing many endemic species (found nowhere else in the world) and a large number of endangered species, protecting these spots is priority for many conservationists
final mark re-capture equation?
m/r=s/N
what does mark re-capture assume
same likelyhood of being sampled, marked individuals mix completely, no one dies birth or leaves
what is r-selection?
selection that favours traits at low densities, for a high reproductive success (mature rapidly, short lifespan, large number of offspring, high mortality rate)
what is MVP
Minimum Viable Population size (smallest size at which a population is able to sustain its number and survive)
takes into account Ne, individual range, mortality rate, reproductive age
logistic populations are typical of
microorganism cultures (bacteria)
what is a life table
summarizes survival/reproduction of individuals in specific age groups, tracks a female cohort
3 categories of ecosystem loss
3 status categories: collapsed, critically endangered and endangered
what do we assume for exponential population growth
unlimited resources, colonize new environment, new species or rebound from catastrophic event
logistic population growth equation
dN/dt=rN x (k-n)/k
how does population density change
= births+immigration-deaths-emigration
what is k-selection
selection that favours traits at high densities, at or near the carrying capacity K (mature more slowly, longer lifespan, have few offspring at a time, low mortality rate)
genetic diversity
diversity within and between populations. A decrease in genetic diversity (extinction of a population) can prevent microevolution and limit the adaptive potential of a species
What is the IUCN
International Union for Conservation of Nature- assesses the global conservation
status of species and maintains a Red List of Threatened Species, large fraction of most species is threatned
what is a extinction vortex
Small populations are prone to extinction
because they are vulnerable to inbreeding and genetic drift, lower fitness- reduces the population size even further in an extinction vortex
(positive feedback loop)
what is current high loss of biodiversity due to
high rate of extinction of all known extant species
ecological diversity
variety of ecosystems. The altering of ecosystems
can cause species loss, loss of ecological functions, decline in distribution, disruption of biotic processes and species interactions.
what type of curve does logistic population growth produce
a sigmoid (s-curve) curve, increase in population size is fastest at intermediate
what is life history/ examples
all traits that affect organisms schedule of reproduction and survival (mass at birth, reproductive lifespan, age at death, freqeuncy of reproduction, etc)
what are some threats to biodiversty
habitat loss, invasive species, overharvesting, pollution, acid precipitation, biomagnification (increase across trophic levels), global warming
species diversity
variety of species within an ecosystem or across the
biosphere. The loss of a species can be local (extirpation) or global (extinction)
examples of conservation initiatives
Captive-breeding program to breed endangered species in zoos, organization with a focus
on potato to enhance access to affordable nutritious food in developing countries with sustainable agriculture, national parks to maintain ecological processes and prescene of species
exponential population growth
Growth of a population in ideal, unlimited environment, represented by J-shaped curve when population sizes is plotted overt time
what are the two life history strategies
many small offspring or few large offspring
population dynamics?
study of how complex interactions between biotic and abiotic factors influence variations in population size
survivorship curve
proportion of individuals in a cohort that are still alive at each age
effective population size equation
Ne= (4 x Nf x Nm)/ (Nf+ Nm)
what is carrying capacity K
maximum population size that a particular environment can sustain
what is population density
of individuals per unit area or volume
What is the COSEWIC
Committee on the Status of Endangered Wildlife in Canada- Assesses the conservation status of species found in Canada and makes recommendations to the federal government
if N=K…
the population stops growing, stationary phase
what is conservation biology
The integrated study of ecology, evolutionary biology, physiology, molecular biology, and genetics to sustain biological diversity of all levels
what is being done in habitat conservation
Corridors, connect patches help protect some of the biodiversity
establishment of protected nature reserves (costa rica)
no intervention policy in national parks
3 types of survivorship curves?
Type I: low death rate of juveniles and adults followed by a rapid increase in old age groups (ex: mammals)
Type II: constant death rate (that you can see on a log scale!), constant throughout the organism’s lifespan
Type III: high mortality for the young followed by a flattening of the death
rate in adults (many fish0
what is the mark-recapture method?
sample s individuals (mark them)
release s individuals
sample individuals again (r)
count the number of re-sampled marked individuals (m)
what is demography
study of changes over time in the vital statistics in populations, especially birthrates and death rates
what is a trade-off
trade-off between the number of offspring and the amount of resources invested in each offspring
if population size (N) is small…
growth will be closer to r (exponential phase)
