Evolution and Ecology

Adaptation

Inherited trait enhancing survival and reproduction

Fossil record

History of life preserved in rocks

Variation

Genetic differences within a population

Evolution

Genetic change in a population over time

Artificial selection

Humans breeding organisms for specific traits

Fitness

Ability to survive and reproduce

Natural selection

Survival of organisms best suited to environment

Comparative anatomy

Studying structural similarities and differences between species

Comparative embryology

Comparing embryo development across different species

Homologous structure

Similar anatomy from shared evolutionary ancestry

Analogous structure

Similar function, different evolutionary origins

Genotype

Genetic makeup of an organism

Phenotype

Observable physical characteristics of an organism

Allele frequency

How common an allele is in population

Biogeography

Study of geographic distribution of species

Clade

Group with common ancestor and descendants

Cladogram

Diagram showing evolutionary relationships among organisms

Species

Organisms that can interbreed and reproduce

Speciation

Formation of new and distinct species

Reproductive isolation

Barriers preventing different species from interbreeding

Geographical isolation

Physical separation of populations by geography

Gene pool

Total genetic information in a population

Genetic bottleneck

Drastic reduction in population size and diversity

Genetic drift

Random changes in allele frequencies

Founder effect

Loss of diversity when new population starts

Gene flow

Transfer of alleles between populations

Mutation

Random change in a DNA sequence

Population

Same species living in one area

Divergent evolution

One species evolves into multiple different forms

Abiotic factor

Non-living part of an ecosystem

Biodiversity

Variety of life in an ecosystem

Biomes

Large regions with distinct climates and life

Biosphere

Global ecological system integrating all life

Biotic factor

Living component of an ecosystem

Community

All interacting populations in an area

Ecology

Study of organisms interacting with environment

Ecosystem

Interacting living community and non-living environment

Habitat

Natural home or environment of organism

Carnivore

Animal that eats only other animals

Commensalism

One species benefits, other is unaffected

Competition

Organisms vying for the same resource

Consumers/heterotrophs

Organisms that eat others for energy

Energy flow

Transfer of energy through an ecosystem

Herbivore

Animal that eats only plants

Mutualism

Relationship where both species benefit

Niche

Organism's specific role in its habitat

Omnivore

Animal that eats plants and animals

Parasitism

One benefits by harming a host

Predator

Animal that hunts and kills others

Prey

Animal hunted and eaten by predators

Producers/autotrophs

Organisms that make their own food

Symbiosis

Close, long-term interaction between two species

Trophic levels

Feeding positions in a food chain

Ecological background

Environmental context influencing ecological studies

Food web

Network of interconnecting food chains

Limiting factor

Resource that restricts population growth

Density dependent limiting factor

Factor affecting growth based on population size

Density independent limiting factor

Factor affecting population regardless of density

Immigration

Movement of individuals into a population

Emigration

Movement of individuals out of population

Exponential growth

Rapid, unrestricted population growth

Logistic growth

Population growth slowing near carrying capacity

Carrying capacity

Maximum population an environment can sustain