Invasive species can have what kind of impact on native species?

Invasive species can significantly impact native species primarily through competition for resources such as food, habitat, and space. These invasive species often have traits that allow them to thrive in new environments, such as rapid growth, high reproductive rates, and lack of natural predators. As a result, they can outcompete native species, leading to declines or even local extinctions of those species. This competitive advantage disrupts local ecosystems, alters community dynamics, and can diminish biodiversity in affected habitats.

The other options discuss scenarios that are generally not the result of invasive species. Coexistence is rare when one species is invasive, as they often disrupt existing relationships within the ecosystem. While some may argue that a few invasive species can occasionally increase biodiversity temporarily by filling vacant niches, this is not the typical outcome. Additionally, invasive species do not typically increase genetic diversity among native species; rather, they can homogenize the gene pool by outcompeting or hybridizing with native species. Thus, the most accurate assessment of the impact of invasive species on native populations is their tendency to outcompete and adversely affect those native species.