Speciation

Question 1

What is speciation?

Answer 1

When a species disappears only to be replaced by a new organism; they accumulate small changes over time (microevolution).

Question 2

Explain pre-reproductive isolation mechanisms.

Answer 2

Geographical- individuals are separated by geographical features.
Temporal- breed during diff times/seasons/years etc.
Behavioural- different courtship patterns.
Morphological- have diff reproductive structures; it’s physically impossible to mate.

Question 3

Explain post-reproductive isolating mechanisms.

Answer 3

Gamete Mortality- the gametes don’t survive.
Zygote Mortality- zygote forms, but doesn’t survive.
Hybrid Sterility- an infertile offspring survives; it can’t produce viable gametes.

Question 4

Explain allopatric and sympatric speciation.

Answer 4

Allopatric- when gene flow is disrupted as populations become physically separated through geographical isolation.
Sympatric- the evolution of 2 or more new species from a single population within the same species.