Explain Lamarckism with an example. Why was it rejected?
How to lay out the answer. Follow the frame, then write it in your own words.
1 · Introduce. Lamarckism is the theory of inheritance of acquired characters, by Jean-Baptiste Lamarck in Philosophie Zoologique (1809).
2 · Write the main points.
Internal vital force
Effect of environment and new needs
Use and disuse of organs
Inheritance of acquired characters
3 · Give the example. Giraffe ancestors stretched their necks to reach tall leaves, and longer necks passed to the young. Snakes lost their legs by disuse.
4 · Link to daily life. A wrestler's strong muscles are not seen in the newborn baby.
5 · Give the objection.Weismann cut mouse tails for many generations, yet the young still had tails. So acquired characters are not inherited.
Scoring tip: Four points, the giraffe and Weismann fit a 4-mark answer. Underline 'use and disuse'.
