Answer:
2. is caused by reduced gene flow
Explanation:
Speciation occurs when living organisms develop distinct and unique characteristics due to evolution.
Speciation occurs due geographic migration or movement of species of organisms from one place to another. These species become geographical isolated from each other thereby causing a reduction of gene flow amongst them due to an absence of reproduction.
When these separated species get to their new location , they adapt to the new environment and become distinct species.
We have different types of speciation and they are :
a. Allopatric Speciation
b. Parapatric Speciation
c. Sympatric Speciation
d. Peripatric Speciation
