Three-spine sticklebacks are small fish that originated in the ocean and continue to exist there, but then some took up residence in hundreds of streams and freshwater lakes in the Northern Hemisphere. Predict whether you would expect to find different species in lakes today.

Verified step by step guidance

1. Identify the key concept: Understand that the three-spine sticklebacks have adapted to different environments (oceanic and freshwater).
2. Consider genetic drift and natural selection: Recognize that populations in different environments may experience different selective pressures and random genetic changes over time.
3. Analyze isolation: Acknowledge that populations in separate lakes are geographically isolated from each other, which can lead to reproductive isolation.
4. Predict speciation: Infer that due to different selective pressures, genetic drift, and reproductive isolation, it is likely that different species of three-spine sticklebacks could have evolved in separate lakes.
5. Conclude based on evolutionary biology principles: Given the factors of different environments, isolation, and time, it is reasonable to expect that different species of three-spine sticklebacks might be found in various lakes today.

Key Concepts

Speciation

Speciation is the evolutionary process by which populations evolve to become distinct species. This often occurs when populations are geographically isolated, leading to genetic divergence due to different environmental pressures and selective forces. In the case of three-spine sticklebacks, those that moved from ocean to freshwater environments may have adapted to their new habitats, potentially resulting in the emergence of new species.

Adaptive Radiation

Adaptive radiation is a process in which organisms rapidly diversify into a variety of forms to adapt to different environments. This phenomenon often follows the colonization of new habitats, where species exploit various ecological niches. For three-spine sticklebacks, the transition from marine to freshwater environments could lead to adaptive radiation, resulting in different species adapted to specific lake conditions.

Ecological Niche

An ecological niche refers to the role and position a species has in its environment, encompassing its habitat, resource use, and interactions with other organisms. Different species can occupy different niches, which reduces competition and allows for coexistence. In lakes, three-spine sticklebacks may evolve distinct niches based on factors like food availability and predation, leading to the development of different species.