LO4 Flashcards
Microevolution
consists of change in allele frequency in a population over time
Speciation
evolutionary theory that explains how new species originate and how populations evolve. The origin of new species
Biological Species Concept
- concept that defines species as a group that interbreeds and produce fertile offsprings.
Limitations of the Biological Species Concept
- cannot be applied to fossils or asexual organisms
- absence of gene flow which causes populations to hold a species together genetically
- gene flow can occur in distinct species
Morphological species concept
defines a species by structural features
- it applies to sexual and asexual species but relies on subjective criteria
Ecological species concept
views a species in terms of its ecological niche
- applies to sexual and asexual species and emphasizes role of disruptive selection
phylogenetic species concept
defines a species as the smaller group of individuals on a phylogenetic tree
- applies to asexual and sexual species, can be difficult to determine the degree of difference required for separate species.
What is the existence of biological factors that prevent two species from producing fertile offsprings?
reproductive isolation
what are the crosses between different species?
hybrids
Behavioral Isolation
differences in mating rituals and displays
Temporal isolation
differences in timing of mating
Habitat isolation
differences in habitat occupied
Mechanical isolation
reproductive structure incompatibility
Gamete isolation
sperm and egg cannot fertilize because they are incompatible
Reduced hybrid viability
Hybrids that are unable to compete for mates
