Population Biology

Three types of population distribution

Random, Uniform, Clumped

Density Dependent Factor

A factor that influences an individuals probability of survival and reproduction in a manner that depends on the size of the population (i.e. predation, disease, food supply)

Density Independent Factor

A factor that has the same effect on a individual's probability of survival and reproduction at any populations size

exponential growth models

occurs when populations are not limited by resources. (J-curve)

logistical growth model

occurs when populations reach a carrying capacity established by a limiting resource and initially experience large growth but then level off. However, they do not exist exactly at carrying capacity. They fluctuate above and below.

Type I, II, III Curves

reproductive strategies of different species. Type I fosters their young, Type II does sorta kinda, and type III straight up ditches their kids

K selective strategies

A species with a low intrinsic growth rate that causes the population to increase slowly until it reaches carrying capacity (TYPE I)

R selective strategies

A species with a high intrinsic growth rate that causes the population to overshoot and quickly die off (TYPE III)

Population size

The total number of individuals within a defined area at a given time

Population density

The number of individuals per unit area at a given time

Population distribution

How individuals are distributed with respect to one another

Population age structure

how many individuals fit into age categories. Shown by age structure diagrams

Growth Rate

The number of offspring an individual can produce in a given period of time, minus the deaths of the individual or offspring during the same period

Metapopulations

A group of spatially distinct populations that are connected by occasional movements of individuals between the populations

Competition

The struggle of individuals to obtain a limiting resource

Resource partitioning

Where species work together and divide up a resource like birds in a tree-this can reduce competition

Predation

The use of one species as a resource by another species

Parasites

Type of predation when species live on or in the organism they consume

Parasitoids

Type of predation when species lay eggs inside other organisms

Mutualism

A type of interspecific interaction where both species benefit

Commensalism

A type of relationship in which one species benefits but the other is neither helped nor hurt

Keystone Species

Keystone or Busch? Jk nah this is a species that plays a role in its community that is far more important that ints relative abundance might suggest

Primary Succession

Occurs on surfaces that are initially devoid of soil. Starts with moss and lichens on the exposed rock and it it progresses to shrubs and plants and eventually restores ecosystem.

Secondary Succession

Occurs in areas that have been disturbed but have not lost their soil

Community Ecology

The study of the interactions between species in a habitat

Competitive exclusion principle

two species competing for the same limited resource cannot coexist. This explains why resource partitioning takes place so that both can survive

Interspecific Competition

When two species compete over one limited resource

Intraspecific Competition

When two individuals within the same species compete over one limited resource

Factors that determine species richness

Latitude (distance from equator), Time (older the habitat, the higher SR), Habitat size (larger=greater)

Theory of Island Biogeography

Explains that both habitat size and distance determine species richness

How does the human population not have a food deficit?

Innovation and Technology

growth rate equation

CBR-CDR/10

doubling time for a population equation

70/growth rate

Demography

The study of human populations and population trends

Total Fertility Rate (TFR)

estimate of the average number of children each woman will bear in her lifetime

Replacement level fertility (RLF)

2.1

Developed Countries

Countries with high levels of industrialization and income

Developing Countries

Countries with relatively low levels of industrialization and income

Life Expectancy

The average number of years that an infant born in a particular year in a particular country can be expected to live, given the current average life span and death rate of that country

Infant Mortality Rate

Number of deaths of children under the age of one per 1000 births

Child Mortality Rate

Number of deaths of children under the age of five per 1000 births

Demographic Transition

The theory that as a country moves from a subsistence economy to and industrialized one, it undergoes a predictable shift in population growth

Family Planning

Regulating the number or spacing of children through the use of birth control

IPAT equation

environmental Impact=Population, Affluence, Technology