Chapter 24 - The Origin of Species Flashcards
speciation
An evolutionary process in which one species [believably] splits into two or more species.
microevolution
Evolutionary change below the species level; change in the allele frequencies in a population over generations.
macroevolution
[Believed] Evolutionary change above the species level. Examples of [believed] macroevolutionary change include the origin of a new group of organisms through a series of [believed] speciation events and the impact of mass extinctions on the diversity of life and its [believed] subsequent recovery.
biological species concept
Definition of a species as a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring, but do not produce viable, fertile offspring with members of other such groups.
reproductive isolation
The existence of biological factors (barriers) that impede members of two species from producing viable, fertile offspring.
hybrid
Offspring that results from the mating of individuals from two different species or from two true-breeding varieties of the same species.
prezygotic barrier
A reproductive barrier that impedes mating between species or hinters fertilization if interspecific mating is attempted.
postzygotic barrier
A reproductive barrier that prevents hybrid zygotes produced by two different species from developing into viable, fertile adults.
morphological species concept
A definition of species in terms of measurable anatomical criteria.
ecological species concept
A definition of species in terms of ecological niche, the sum of how members of the species interact with the nonliving and living parts of their environment.
phylogenetic species concept
A definition of species as the smallest group of individuals that share a common ancestor, forming one [believed] branch on the tree of life.
