Answer :
The neck length greatly change among the traits after 25 generations in an environment with only tall thornpalms.
Effect on distribution of traits due to change in environment
The distribution of traits for neck length greatly change in this ostrilope population after 25 generations in an environment with only tall thornpalms because the traits having short neck length extinct from that environment due to unavailability of food for them.
In this environment only long neck traits can survive and live due to the presence of food source at high position so we can conclude that the neck length greatly change among the traits after 25 generations in an environment with only tall thornpalms.
Learn more about traits here: https://brainly.com/question/7375078