Question

What was Lamarck's explanation for long legs and long neck of giraffe? How can this be explained by Darwin's theory of natural selection?

Answer 1

Ancestral giraffes stretched their necks and forelegs to reach leaves on taller trees. The acquired increase in length was, according to Lamarck, inherited and accumulated over generations.

Darwin’s explanation: Ancestral giraffes varied in neck and leg length. When lower leaves became scarce, individuals with naturally longer necks and legs could reach more food, survived and reproduced more successfully, and passed on those heritable variations. Over generations, longer-necked and longer-legged giraffes became common.

Lamarck proposed inheritance of acquired traits; Darwin explained the change through natural selection acting on heritable variation.