Glossary (in order) Module 3 & 4

Ecosystem

every organism in a specific environment, interacting with the abiotic and biotic factors in that ecosystem.

Environment

any space within an ecosystem, equivalent of saying nature (can be chemical, physical or biological).

Habitat

Specific place in an ecosystem where an organism resides.

Community

All the species that are in an environment at the same time that do not need to interact with each other, but can.

Population

Communities are made up of populations. A population consists of a number of individuals of the same species.

Ecosystem

dynamic and constantly changing due to the interactions between organisms and their environment.

Ecological niche

a role a species plays in that ecosystem. Multiple organisms can have multiple niches that include but are not limited to food, habitat, where it reproduces, relationships with other species

Abundance

How many organisms in a specific area

Distribution

How spread out organisms are. Geographical area over where individual oirganisms are dispersed

Symbiotic relationships

Interaction between species, where at least on species benefits

Parasitism

one organism lives on or inside another organism and harms it

Ammensalism

relationship when one organism is harmed, the other is unaffected

Commensalism

one organism benefits and the other is unaffected

Mutualism

both organisms benefit and neither are harmed

Competition

the struggle between organisms to survive in a habitat with limited resources

Scavenger

feeds on already deceased animals

Detritivore

organism that feeds on plant and animal remains and other dead matter

Decomposer

an organism that breaks down wastes and dead organisms

Obligative mutualism

one cannot survive without the other

Facultive mutualism

can live without each other

Adaptation

features that suit organisms to their specific environment

Structural adaptations

physical features of an organism

Behavioral adaptations

the way an organism acts to help them survive

Physiological adaptations

the way an organism processes to help them survive

Convergent evolution

process by which unrelated organisms independently evolve similarities when adapting to similar environments

Divergent evolution

when two or more species sharing a common ancestor become more different over time

Comparitave embryology

compares the similarities and differences between different species' embryos as evidence of evolution

Selection pressures

forces that promote reproductive success of some individuals more than others

Positive selection pressure

a factore that increases the likelihood of particular species or variations within a species surviving to reproduce

Negative selection pressure

a factor that decreases the likelihood of particular species or variations within a species survivin to reproduce

Biodiversity

The variations found within the genetics, species and ecosystems of living things

Interspecific competition

competition in an ecosystem for resources such as food and habitat between members of different species

Intraspecific competition

competition in an ecosystem for resources such as food and habitat between members of the same species

Competition exclusion principle

no two species can occupy the same niche in the same habitat at the same time

Natural selection

a process in which individuals that have advantageous inherited traits survive and pass those traits onto their offspring, and those without these traits will die more easily

Four steps of natural selection

variation, selective reproduction, inheritance, gradual change in population

Sexual selection

a form of natural selection in which individuals with favourable traits are more likely than other individuals to obtain mates

Microevolution

small changes that occur in the genetic biodiversity of a species over time. these occur in response to natural selection

Speciation

the formation of two or more distinctive species from one ancestral species

Repoductive isolation

prevention of mating between members of due to physical separation or variation in traits involved in mating

Comparative anatomy

the study of similarities and differences among structures of living species as evidence for a common ancestor

Selective breeding

the human practice of breeding animals or plants that have certain desired traits

Biogeography

Study of past and present distribution of organisms, as evidence for evolution

The fossil record

chronological collection of life's remains in sedimentary rock layers and comparison between these fossils

Vestigal structure

structure in an organism that is genetically inherited that no longer appears to function in the same way as it did in an ancestor (useless organ or bone)

Complete count

locating and counting every single indicidual in a population to accurately determine the precise population size

Random quadrats

all organisms are counted that are found within a 1x1 metre square and is repated in randomly chosen places to estimate the total population sixe within a given area.

Capture-mark-recapture

a method of estimating the population size of moving animals based on safely trapping and marking individuals the recapturing a sample and noting how many are marked

Transect sudy

an approach to exame the distribution of an organism often in response to an abiotic factor. population estimates at different regions of the area can be determined

Biosphere

part of earth in which life exists including land, water, and air or atmosphere