Interspecific competition
when members of 2 or more species interact to gain access to the same limited resources.
once species feeds directly on members of another species
(+,-) parasite is gaining and host is getting hurt
+, += both benefitting
“competitive exclusion principle”
no two species can occupy the same ecological niche for very long.

this makes competition and the one that is better wins.

A member of one species feeds directly on all or part of a living organism of another plant or animal species as part of a food web
Detritus feeders and decomposers are not considered predators
they don’t feed on living organisms
Difference in predation between herbivores and carnivores
Herbivores=can simply walk, swim, fly up to plants ex) urchins Carnivores feed on mobile prey
“Chemical warfare”
common strategy some species discourage predators with chemicals that are poisonous (skunk=smell)
prey avoid predators
camo, chemical warfare, coloration, mimicry, deceptive behaviors
when population of 2 different species interact in this way over time, changes in the gene pool of one species can lead to changes in the gene pool of the other one
benefits of coevolution
maintaining long term sustainability through population control
resource partitioning
some species evolve to reduce niche overlap.ex) birds feeding in different parts of the tree
environmental conditions
Population dynamics is the study of how characteristics of populations change in response to changes in this
ex) elephants most common
uniform dispersion
equally spread apart
random dispersion
tendency for populations to be found randomly about their habitat
opportunists no parental care
k-selected species
reproduce later in life mature slow cared by parents
the result of a founder effect can be that ________ or variability may threaten the survival of the population
limited genetic diversity
demographic bottle neck
a catastrophe occurs such as fire and a few survive
founder effect
few individuals in a population colonize a new habitat that is geographically isolated from others
genetic drift
random changes in the gene frequencies in a population that can lead to unequal reproductive success
when individuals in a small population mate
edge habitat, suburbanization
the border area that white tailed deer utilize
which of the two successions take the longest
primary because it is a gradual establishment of biotic communities in life-less areas where there is no soil
secondary succession
series of communities or ecosystems with different species develop in places containing soil or bottom sediment
Inertia or persistence
ability of a living system such as a grassland or forest, to survive moderate disturbance
ability of a living system to restore through secondary succession after moderate disturbances
replacement Fertility rate
The average # of children that couples in a population must bear to replace themselves
Fertility rate
the # of children born to a women during her lifetime
Average # of children born to women in a population during their reproductive years
Demographic transition
first their death rates and birth rates decline
population grows very slowly because of a high birth and death rate
population grows rapidly because birth rates are high and death rates drop because improved food production
population growth slows as both birth and death rates drop because of improved food production, health and education
family planning
huge factor in reducing the # of births and abortions throughout the world