Macroevolution Part 3 - Sympatric Speciation

Allopatric Speciation

The formation of new species in populations that are geographically isolated from one another.

Parapatric Speciation

speciation pattern in which populations speciate while in contact along a common border

Sympatric Speciation

The formation of new species in populations that live in the same geographic area

Polyploidy

refers to instant
speciation which occurs in most
often in plants. The normal primrose is
diploid with 14
chromosomes. 2N = 14
• In this species there was
a total nondisjunction
event resulting in
primroses that are
tetraploid. 4N = 28
• These primroses cannot
successfully mate with
the diploid species.

Autopolyploidy

refers to the occurrence in which
the number of chromosomes doubles in the offspring due to
total non-disjunction during meiosis.

Allopolyploidy

a species with multiple sets of chromosomes derived from different species

Gradualism

The theory that evolution occurs SLOWLY but steadily

Punctuated Equilibrium

the hypothesis that evolutionary development is marked by isolated episodes of RAPID speciation between long periods of little or no change.