The <span>amount of food, habitat, water, and other necessities available in the </span>environment<span>.</span>
How can reproductive isolation lead to speciation<span>? If populations cannot mate successfully with one another, genetic differences may accumulate in the populations. Over time they become very different and give rise to new species.</span>
I think it's true hope I helped:)
Answer:
pathogens
Explanation:
pathogens may occur in various way e.g spread from a person to person by directly body contact