Earth's birds developed their diversity through natural selection by some birds need to have long beaks if they need to fish and some need webbed feet to swim. They have these traits through natural selection.
Answer: because they cannot be produced in the body and must be consumed from outside sources
Answer:
Option-C
Explanation:
Scientists found a fossil of a fish with four limbs or legs. The fossil was estimated to be around 375 million years old.
The fossil showed the fins and scales of a fish but they also possess the bones of proto-wrist, shoulders and the elbow.
The presence of these bones can be a clue that the fish evolved the limbs to walk on the land and will later evolve into animals belonging to amphibians, reptiles and mammals. Therefore, the Tiktaalik is considered the missing link of how life evolved from water to land.
Thus, Option-C is correct.