Apes Ch.6 Flashcards
Population
A group of the same species
Population ecology
Study of the rise and falls of certain species, populations are dynamic
Inputs
Birth and immigration
Outputs
Emmigration and death.
What is the value of a population study
Important to know how many male and female, might give us a chance to help dying populations if we know how to help it.
Population size
Total number of organisms of that species
Population density
How close the individuals are from the species, how packed
Population density formula
Number of organisms divided by the area of the habitat
Endangered
Numbers are so few, on the verge of Extinction
Threatened
Not as bad as endangered, but on the verge of being endangered
Population distribution
Where the Organisms are in relation to the others
Random distribution
Not everything in the same place, scattered
Uniform distribution
Often associated with birds, if anyone goes in their territory they will get killed, they are equidistant from each other
Population sex ratio
Used to get an idea about offspring
Population age structure
Only used for people, based on age
Dark green
Pre -Reproductive group, 15 and under
Medium green
Reproductive group, 15 through 45
Light green
Post reproductive group, 45 and up
How do you find the future population
Look at the amount of pre reproductive group
Why is immigration wanted
Food, intellect, diversity, etc
What are the two factors that influence a population
Density dependent and density Independent
Density dependent
Has a greater effect people are closer to each other, for example a virus
Density Independent
Population is far apart, so a flood would affect this population
Exponential growth
True exponential growth doubles each generation, reproduction starts slow, not very realistic because it cannot keep going forever because they will eventually run out of space and resources
J shape graph
Limiting factors
Factors necessary for survival
Formula to predict how big a population is
N. = N. E^(r)(t)
T. O
R=growth rate
T=time
Logistic growth
Grows rapidly for a while then levels out
S shape graph
Carrying capacity
Number of resources available for the species, when the species reaches their limit, they are going to reduce their population
Overshoot
A population might exceed carrying capacity if it is allowed by more resources
Die off
Population starts to decrease below carrying capacity
Preditation
Predator prey relationships
Why do predators increase after preys increase
When prey increases there are more food resources for the predator to increase
What do invasive species lack
Predators
Describe r and k selected species
K selected species increase population slowly, because they live longer and have a longer generation time, take longer to take reach maturity, offsprings are larger, fewer, and offspring requires care.(humans)
R selected species are the opposite(frogs)
Survivorship curves
How long you expect a organism to live
Type 1
Lose very few in the beginning, dies slowly, humans
Type 2
Just as likely to die early or to die old
Type 3
Dies very quickly
Metapopulation
Group of the same species, but located in different areas, species of these populations move from one group to another group
Corridors
Connections between the habitats for species to go to one to another
Anthropogenic corridor
Connection between habitats but man-made
Competition
Struggle of organisms to obtain the same limiting resource
Competitive exclusion principle
Two organisms competing for one resource, one will be successful one will not
Resource partitioning
Limited resources, each organism shares the food and can maintain their population levels by sharing and having more than one resource
Temporal resource partitioning
Same resource but not direct competition, for example wolves eat during the day but coyotes eat during the night
Spatial resource partitioning
Competing for the same resources from different areas, for example plants competing for water but one gets their water from the deeper ground one gets it from the top ground, competing, but from different places
Morphological resource partitioning
Morphology is structure, competing for the same resource but their structure is different. For example, a big predator has a big jaw and eats big or adult seeds, while a small animal with a smaller jaw is still competing for the same resources but eats small seeds
Why is a cow eating a plant not true preditation
Because it is an animal eating a plant not eating another animal
Pathogens
Survives by devouring organisms, for example viruses, bacteria, fungi
Parasitoids
Organism lays an egg inside another organism
Parasite
Organism that lives in another organism, and other organism is called a host
Prey defenses
To avoid being eaten or harmed by a predator
Behavioral defense
Standing still, running
Morphological defense
Structures, such as spines, thorns, sharp teeth, etc
Chemical defense
Mosquito bite, snake venom
Mimicry defense
Looking like different species
Symbiotic relationships
Occurs when two organisms live very close to each other, can even be like inside for example a coral reef
Mutualism
Both species benefits
Examples of mutualism
Acacia trees and ants
Lichen and fungus
Coral and polypus
Symbiosis commensalism
One of two organisms benefit, while the other is not affected for example birds and trees
Parasitism
When organism benefits while one is harmed
Keystone species
Gets its name from architectural buildings built from stone, they are species that must be there or the ecosystem collapses for example starfish they increase the biodiversity of coral reefs
Ecological succession
Process of change in a species over time
Succession
Orderly change in type of species over time, very predictable
Primary succession
Change in species in an area without soil in the beginning, starts in areas without dirt but plants can grow because of a pioneer plant.
Pioneer plants
First plant in primary succession
Secondary succession
Change form, devastated area but soil is still present, weed is likely to be a pioneer plant in secondary succession
How is it possible to get soil from one place to another place without soil
Erosion and weathering, a lot of soil is carried in the wind
Climax plants
Last plants usually trees
Theory of island biogeography
What the number of organisms on an island depend on, this is a theory or an explanation of how many species there are on every island
What is the theory of Island biogeography
This is a theory where the size of the island, distance from the mainland, and its biotic and abiotic factor is explained.
The bigger the island, the more species it has, the more habitats and resources the more species, the closer the island is the mainland the more species it has because it’s closer to fly or swim to.
