Speciation can be difficult to observe in nature, but the it is hypothesized that the following occurs in a allopatric speciation's intermediate stage:
(1) closely related species are differentiated through geographic variation (2) then there's reduced fertility in one a geographic race of the species (3) and in the geographic race of subspecies that are to become species.
Answer:
Answer is A. allow them to control all the variables involved.
Explanation:
Modelling in ecology means the use of constructed mathematical models for understanding of ecological processes and to predict or know how real it is for ecosystem to change.
Ecological modelling is useful in defining problems more precisely and clarity of concepts.
When a Stickleback fish feels threatened, it will flare out its pair of pelvic spines and three dorsal spines, making it difficult for predators to swallow them.