AP Biology: Ecology

Biological Magnification

Biological magnification is the process by which toxins accumulate, becoming more concentrated, as they move up the food chain.

Keystone species

A species within and enviorment that are extremely crucial - ex. wolves yellowstone

Type III survivorship

Organisms with Type III survivorship curves experience high early mortality.

Commensalism

population benefits and the other is unaffected +/0

Carrying Capacity

Maximum population size that a particular environment can sustain

Logistic population

Population growth increase will reach zero as the population reaches carrying capacity

Mutualism

A relationship in which both interacting members benefit. +/+

An increase in the population density of a predator species leads to increased selective pressure on prey species, favoring individuals with better camouflage.

Directional selection

Chemosynthesis

Inorganic matter to produce organic matter.

Population 

Groups of individuals belonging to the same species in a given area.

Communities

Units composed of all the populations living in  given area

Ecosystem

All communities and their physical processes.

Niche Partitioning

When different species within an ecosystem divide resources (like food, space, or time) to minimize competition

Natural Selection

Species survival based on enviorment Ex. Giraffes neck tree food

Artificial Selection

Human caused selection Ex. Wolves into weiner dogs.

Convergent Evolution

Similar traits adapted for similar enviorments ex. Duck, whale, shark, dolphin

Mutations

Random beneficial or detremental changes in dna

Genetic Drift

Random changes within small populations

Bottleneck effect

Reduce in population, change in alleles, not caused by natural selection. 

Founder Effect

New population from a bigger one has a primary allele 

Gene Flow

Genes moving withing populations

Speciation

Creation of new species because of reproductive behaviors (Pre and Post zygotic) 

Adaptive Radiation 

Speciation from one ancestral species with distinct traits that exploit niches in the enviorment. 

Stabilizing Selection

A type of natural selection where intermediate, or average, phenotypes are favored

Directional Selection

Selection for extreme phenotype 

5 Constants in Hardy-Weinberg

equilibrium include population size, no mutations, no migration, random mating, and no natural selection.

Analogous Structures

Stem from convergent evolution - not sharing common ancestor

Prezygotic 

Before zygote is created: 

• Behavioral (mating rituals)

• Temporal (different time that the mating occurs)

• Geographical (two organisms are separated)

• Habitat (different enviorment)

Postzygotic

After zygote is formed

• Healthy

• Sterile

• Viable

Sympatric Speciation

How speciation occurs in the same area - access of gene flow- resource favorability in the area - without geographical isolation 

Endothermic 

Maintains body temp with metabolism  Ex. Mammals

Ectotherm

Maintains body tempature through behaviors Ex. coldblooded creatures

Autotroph

Bottom of trophic structure: gain from chemicals or sunlight - photo or chemo synthetic 

Heterotroph

Get energy through other organisms

Alturistic behavior

Sacrificial Behavior