What occurs as a result of the arrival in a new uncolonized habitat?

The arrival in a new uncolonized habitat typically leads to adaptive radiation. This phenomenon occurs when a single ancestor species rapidly diversifies into a wide array of forms to adapt to various environmental niches. When an organism colonizes a new habitat, it often faces different selective pressures compared to its original environment. As a result, evolutionary changes take place, allowing the species to exploit new resources or adapt to specific environmental conditions.

For example, the finches of the Galápagos Islands exemplify adaptive radiation. A few finch species arrived at the islands and subsequently evolved into several distinct species, each adapted to different feeding strategies and habitats available in that ecosystem. This process highlights the capacity for species to adapt and evolve in response to ecological opportunities in a new environment, thereby increasing biodiversity.

Other options like allopatric speciation refer to the formation of new species due to geographical isolation, genetic isolation leads to sympatric speciation which occurs within a shared habitat, and mechanical isolation describes reproductive barriers after species have already formed. These concepts, while important in evolutionary biology, do not directly address the immediate effects of colonizing a new, uncolonized habitat as adaptive radiation does.