What is the term for factors that directly affect mating and reproduction between species?

The term that refers to factors directly affecting mating and reproduction between species is prezygotic isolating factors. These factors play a crucial role in preventing mating or fertilization between different species, which is essential for maintaining species boundaries and promoting speciation.

Prezygotic isolating factors include a variety of mechanisms such as temporal isolation, where species breed at different times; behavioral isolation, where differences in mating behaviors prevent species from recognizing each other as potential mates; and mechanical isolation, which occurs when physical differences in reproductive organs prevent successful mating. By acting before fertilization occurs, these factors effectively reduce the likelihood of hybrid formation and help maintain the genetic integrity of distinct species.

In contrast, postzygotic isolating factors come into play after fertilization has occurred, affecting the viability or fertility of hybrid offspring. Pheromonal factors specifically refer to chemical signals used for communication, usually related to mating but are not a classification of isolating mechanisms. Environmental factors encompass broader ecological elements that can influence species interactions but do not specifically focus on reproductive barriers.