Ecosystem Diversity
the variety of ecosystems within a given region
Species Diversity
the variety of species within a given ecosystem
Genetic Diversity
the variety of genes within a given species
Species Richness
the number of species in a given area
Species Evenness
the relative proportion of different species in a given area
Phylogenies
the branching patterns of evolutionary relationships
Evolution
a change in the genetic composition of a population over time
Microevolution
evolution occurring below the species level
Macroevolution
evolution that gives rise to new species, genera, families, classes or phyla
Genotype:
the complete set of genes in an individual
Mutation
a random change in the genetic code produced by a mistake in the copying process
Recombination
process by which one chromosome breaks off and attaches to another chromosome during reproductive cell division
Phenotype
a set of traits expressed by an individual
Artificial Selection
a breeder chooses to perpetuate certain desirable inheritable traits in a plant or animal
Natural Selection
survival of a species due to it being most suited to the environment
Fitness
an individual's ability to survive and reproduce
Adaptation
a trait that improves an individual's fitness
Genetic Drift
a change in the genetic composition of a population over time as a result of random mating
Bottleneck Effect
a reduction in the genetic diversity of a population caused by a reduction in its size
Founder Effect
a change in a population descended from a small number of colonizing individuals
Geographic Isolation
physical separation of a group of individuals from others of the same species
Reproductive Isolation
two populations within a species evolving separately so they can no longer interbreed and produce viable offspring
Allopatric Speciation
the process of speciation that occurs with geographic isolation
Sympatric Speciation
the evolution of one species into two, without geographic isolation
Genetic Engineering
direct manipulation of genetic material in order to alter the hereditary traits of a cell, organism, or population
Genetically Modified Organisms
an organism produced by copying genes from a species with a desirable trait and inserting them into another species
Range of Tolerance
the limits to the abiotic conditions that a species can tolerate
Fundamental Niche
ideal environmental conditions for a species
Realized Niche
range of abiotic and biotic conditions under which a species actually lives
Distribution
areas of the world in which a species live
Niche Generalists
a species that can live under a wide range of abiotic or biotic conditions
Niche Specialists
a species that is specialized to live in a specific habitat or to feed on a small group of species
Mass Extinction
a large extinction of a species in a relatively short period of time