He idea that offspring inherit traits that their parents acquired by interacting with the environment, like the longs necks of giraffes having evolved to them reach tall branches, was championed by

Didn't quit understand the question but if you were asking who basically came up with the idea of offspring inherited traits then the idea was proposed in ancient times by Hippocrates and Aristotle and was commonly accepted near to Lamarck's time.

Schist. hope it