speciation and macroevolution Flashcards
speciation
the splitting of one species into two or more species
macroevolution
evolution on a larger scale
taxonomist
a scientist who classifies organisms into groups
morphological species concept
species are distinguished from each other by one or more distinct physical characteristics
diagnostic traits
one or more distinct physical characteristics
cryptic species
species that look almost identical but are very different in other traits.
evolutionary species concept
identification of certain morphological traits to distinguish one species from another
biological species concept
reproductive isolation to identify different
species; cannot be tested in nature
prezygotic isolating mechanisms
prevent reproductive attempts or make it unlikely that fertilization will be successful if mating occurs
habitat isolation
he two species occupy different habitats, even
within the same geographic range, and are not likely to meet and attempt to reproduce
temporal isolation
species live in the same locale but reproduce at
different times of the year
behavioral isolation
courtship patterns that allow males and females to recognize one another.
mechanical isolation
when animal genitalia structures are incompatible and reproduction cannot occur.
gamete isolation
when gametes of different species meet they don’t form a zygote
postzygotic isolating mechanisms
operate after the formation of a zygote
hybrid inviability
a hybrid zygote may die because it is not viable
hybrid sterility
The hybrid zygote may develop into a sterile adult
allopatric speciation
he eventual result of populations that have
become separated by a geographic or other type of physiological barrier
sympatric speciation
Speciation that occurs in the absence of a
geographic barrier
adaptive speciation
a type of speciation that occurs when a single
ancestral species rapidly gives rise to a variety of new species as each adapts to a specific environment
convergent speciation
occurs when a biological trait evolves in two
unrelated species as a result of exposure to similar environments
gradualistic model of evolution
Slow and gradual changes gives rise
to new species
punctuated equilibrium model
assembly of species in the fossil record can be can be explained by periods of equilibrium, or stasis, punctuated (interrupted) by periods of rapid speciation
