Answer: D. A river separates members of a squirrel population that used to occupy the same geographical area.
Explanation:
Allopathic Speciation occurs when a geographic barrier (river, mountain, or canyon) separates members of a population
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Earth's crust is generally divided into older, thicker continental crust and younger, denser oceanic crust..The crust is made of solid rocks and minerals.
The mantle lies between Earth's dense, super-heated core and its thin outer layer, the crust. The mantle is about 2,900 kilometers (1,802 miles) thick, and makes up 84% of Earth's total volume.
The core lies beneath the cool, brittle crust and the mostly-solid mantle. ... Earth's core is the very hot, very dense center of our planet. The ball-shaped core lies beneath the cool, brittle crust and the mostly-solid mantle.1
The fibrous skeleton of the heart
functions in all of the ways listed in the option, except causing direct spread
of electrical impulses from the atria to the ventricles. The fibrous skeleton
in fact supports proper coordination of atrial and ventricular contractions by
blocking direct spread of electrical impulses from atria to ventricles.
