Final answer:
The three main factors influencing the distribution and abundance of species in ecosystems are evolutionary history, which dictates species' adaptations; habitat suitability, which encompasses the resources and conditions needed for survival; and ecosystem engineers, which are species that significantly alter the environment.
Step-by-step explanation:
The distribution and abundance of species in ecosystems are primarily influenced by three main factors: evolutionary history, habitat suitability, and ecosystem engineers. Evolutionary history includes the unique adaptations and characteristics that have evolved in a species over time, allowing it to survive in certain environments. Habitat suitability involves the availability of resources such as food, water, and shelter, as well as appropriate conditions like temperature and soil type, which are necessary for a species' survival.
Lastly, ecosystem engineers are organisms that significantly modify the environment in ways that create new habitats or alter resource availability for other organisms. Examples include beavers, which build dams and change water flows, or corals, which build reefs that provide structures for myriad marine species. These factors must be considered when examining how species interact with their environment and with each other, ultimately shaping the dynamics within ecosystems.