Ecological terminology

• Taxonomy - the science of grouping together organisms according to their similarities in physical characteristics and genetic code.

  A taxonomic group is called a taxon.

  Changes in taxons are due to new discoveries of DNA/genetic code - based on phylogeny (using genetic data to organise species into groups.

  The only organisms still only classified by physical characteristics are dinosaurs.
• Species - a group of organisms that naturally breed and produce fertile offspring.

  Most organisms can't breed due to anatomical, behavioural and genomic differences.

  Canis Familiaris - domestic dogs - don't fit this definition
• Species are named by binomial Nomenclature - two name system

  Rules:

  1. They must be in a dead language - Latin or Greek
  2. Genus comes before species
  3. Written in italics or underlined
  4. The Genus has a capitalised first letter but the species name doesn't
• Evolution - the process that changes the gene pool of a species over time

  Gene pool - the variation of genes within a population. Genes are added by mutation and removed by extinction.

  Evolution is driven by increasing chance of survival - natural selection - and reproduction - sexual selection.

  If a population becomes isolated, they may become a new species - speciation e.g. Galapagos Finches

  Evolution is the only process that produces new species naturally.
• Habitat - area or location where a species or community lives
• Ecological niche - the role that an organism plays in its habitat e.g. seed dispersal, food web, pollination, habitat provision.

  In a single habitat, two species cannot occupy exactly the same niche. One will outcompete the other causing them to migrate away or go extinct in that area.

  Niche differentiation - some species change their niche so they can sty in the same habitat e.g. warblers:

  If one species is in a tree, it will feed on the whole tree. However if there are three species in one tree, they will stay in separate levels of the tree to feed.
• Population - all the individuals of a single species that live in a particular area.

  Births and immigration increase population.

  Deaths and emigration decrease population.

  In most cases these factors are equal

  Population = (births + immigration) - (deaths + emigration)
• Community - all the members of all the species that live in an area.

  Includes the interactions between the population within the community
• Ecosystem - biotic and abiotic factors interacting in an area. This includes the community and their inter-species relationships and their relationships with the physical environment.
• Biome - a large geographical region with specific climate conditions within which a characteristic community of species live e.g. tundra, arid desert, tropical rainforest, lakes, coral reefs