What did Lamarck believe would happen to older, unused structures as new adaptations took over for them

Lamarck's Theory of Evolution

Explanation:

Lamarck's theory of evolution was based around how living beings (for example animals, plants) change during their lifetime, and then pass these progressions onto their offspring The model used to explain the concept of utilization and neglect is the stretched neck of the giraffe As indicated by Lamarck's hypothesis, a given giraffe could, over a lifetime of stressing to arrive at high branches, build up a lengthened neck The development of long neck in giraffes is an example of Lamarck's theory of evolution