The work of Lamarck - Evolution - AQA - GCSE Biology (Single Science) Revision - AQA - BBC Bitesize

The work of Lamarck

Charles Darwin is recognised as the scientist most associated with the theory of evolution, however, a number of other scientists were influential in this field.

Lamarck's theory

At the beginning of the 19th century Jean-Baptiste Lamarck was a French scientist who developed an alternative theory of evolution before Charles Darwin.

Lamarck's theory involved two ideas:

  • a characteristic which is used more and more by an organism becomes bigger and stronger, and one that is not used eventually disappears
  • any feature of an organism that is improved through use is passed to its offspring

However, through modern science we now know that in the vast majority of cases this type of inheritance cannot occur.

Lamarck's theory cannot account for all the observations made about life on Earth. For instance, his theory implies that all organisms would gradually become complex, and simple organisms disappear.

This is an image of a sequence of the stages of a giraffe’s growth.

Lamarck's theory suggested that the giraffe's original short-necked ancestor repeatedly stretched its neck to reach the higher branches to eat. Lamarck believed that the stretching elongated the giraffe's neck, which became a useful characteristic and was passed onto future generations. This resulted in the length of the giraffe's neck increasing over time.

It is now commonly accepted that Lamarck's ideas were wrong. For example, simple organisms are still detected in all varieties of life, plus it is now known that mutations can create variation such as neck length.