Why is it likely that most speciation is allopatric? because disruptive selection between forms of traits in sympatric populations is always very strong. because vicariance events are common. because related species are always found in allopatry rather than in sympatry. because gene flow between populations prevents genetic divergence in sympatry. because gene flow between diverging populations is strong in allopatry.

Because gene flow between populations prevents genetic divergence in sympatry

Explanation:

Allopatric speciation is a form of speciation (creation of new species) that occurs as a result of geographic isolation. This means that a part of population becomes physically separated from the initial main population. There is no gene flow between these two populations and as a result the two populations  reach a high level  of genetic divergence. They can no longer interbreed which means they become two different species (speciation).

New populations evolve as result of mutation, genetic drift and natural selection.

Sympatric speciation is a form of speciation without geographic isolation, usually due to  the reproductive isolation or changes in the chromosomes of the organism.

it would affect precipitation by causing flooding in some areas of the world due to climate increasing, causing the glaciers in the northern and southern pole of our planet to melt.

i wish you would have provided choices to simplify it and allow me to give an exact answer.

1: most common garden plants prefer loam — soils with a balance of different-sized mineral particles (approximately 40% sand, 40% silt, and 20% clay) with ample organic matter and pore space. however, some plants grow better in sandy soils, while others are well-adapted to clay soils.

2: available water capacity is the maximum amount of plant available water a soil can provide. it is an indicator of a soil's ability to retain water and make it sufficiently available for plant use. available water capacity is the water held in soil between its field capacity and permanent wilting point.

3: it is the same for all living things (plants and animals). it also includes very tiny organisms that our eyes cannot see. they are known as microorganisms, and include viruses, bacteria and fungi.