The evolutionary theory put forward by Jean-Baptiste de Lamarck in 1809. He postulated that a characteristic that is acquired during the lifetime of an organism as a result of environmental pressures can be transmitted to the next generation. This is the theory of the inheritance of * acquired characteristics and Lamarck believed that new species could arise in this way. Erasmus Darwin also supported this view, but Lamarck was the first to give examples, one of which concerned the seeds of marsh plants. He suggested that if they reached high ground they became adapted to drier conditions by the development of new acquired characteristics, which could be inherited by the succeeding generation resulting in the development of a new species. The theory was later accepted by Darwin (see pangenesis ) but challenged by Weismann. Today Lamarckism has been almost entirely rejected in favour of Neo-Darwinism. See also Weismannism. |
