Lamarckism
Darwin's pangenesis

Charles Darwin 's On the Origin of Species proposed natural selection as the main mechanism for development of species, but (like Lamarck) gave credence to the idea of heritable effects of use and disuse as a supplementary mechanism. Darwin subsequently set out his concept of pangenesis in the final chapter of his book The Variation of Animals and Plants Under Domestication (1868), which gave numerous examples to demonstrate what he thought was the inheritance of acquired characteristics. Pangenesis, which he emphasised was a hypothesis, was based on the idea that somatic cells would, in response to environmental stimulation (use and disuse), throw off ' gemmules ' or 'pangenes' which travelled around the body, though not necessarily in the bloodstream. These pangenes were microscopic particles that supposedly contained information about the characteristics of their parent cell, and Darwin believed that they eventually accumulated in the germ cells where they could pass on to the next generation the newly acquired characteristics of the parents.
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