Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

What is a key component of Lamarck's theory of evolution?

1. Natural selection is the primary mechanism of evolution

2. Species cannot change over time

3. Organisms can inherit acquired traits

4. Mutation rates are constant across generations

The correct answer is: Organisms can inherit acquired traits

A key component of Lamarck's theory of evolution is that organisms can inherit acquired traits. Lamarck proposed that characteristics developed during an organism's lifetime could be passed on to its offspring, suggesting a mechanism for evolutionary change based on the needs and activities of the organism. For instance, he famously illustrated this idea with the example of giraffes, suggesting that their necks became longer over generations as they stretched to reach higher foliage, and this acquired trait would then be inherited by the next generation. This concept contrasts with the principles of natural selection, which involves competition and survival based on existing traits rather than the inheritance of traits acquired during an organism's life. Additionally, the idea that species cannot change over time is contrary to Lamarck's beliefs, as he argued for gradual changes driven by the adaptation of traits. Mutation rates being constant across generations reflects modern evolutionary biology concepts rather than Lamarck's theories. Thus, the idea of inheritance of acquired traits remains a defining characteristic of Lamarckian evolution.