Arrange the evolutionary events representing the process of adaptive radiation following ecological colonization in the correct sequential order from earliest to latest:
- 1Colonization of a newly formed isolated ecosystem by a generalist ancestral founder species.
- 2Rapid population expansion resulting in heightened intraspecific competition for available primary resources.
- 3Ecological divergence as subpopulations undergo natural selection and adapt morphologically to diverse niches.
- 4Development of reproductive isolation mechanisms between specialized subpopulations, completing speciation.
Answer
The correct evolutionary sequence is: Colonization by an ancestral founder species -> Rapid population expansion and competition -> Ecological divergence into distinct niches -> Development of reproductive isolation leading to speciation.
Adaptive radiation begins with colonization, where a single founder species enters a new environment with minimal competition. As the population grows, competition for resources forces subpopulations to exploit unexploited ecological niches. Natural selection drives morphological divergence to optimize efficiency within these distinct roles. Finally, reproductive isolation arises between ecological specialists, preventing interbreeding and securing the formation of multiple distinct species.
Step-by-Step Solution
Key Concept
Sequential Stages of Adaptive Radiation