10.3 Current Views on ‘Lamarckism’
The argument that instinct in animals is evidence for hereditary knowledge is generally regarded as false. Current views suggest that behaviours are more probably passed on through a mechanism called the Baldwin effect. While such a theory might explain the observed diversity of species and the first law is generally true, the main argument against Lamarckism is that experiments simply do not support the second law —purely “acquired traits” do not appear in any meaningful sense to be inherited.
Several historians have argued that Lamarck’s name is linked somewhat unfairly to the theory that has come to bear his name, and that Lamarck deserves credit for being an influential early proponent of the concept of biological evolution, far more than for the mechanism of evolution, in which he simply followed the accepted wisdom of his time. Darwin, like Lamarck, lacked a plausible alternative mechanism of inheritance -the particulate nature of inheritance was only observed by Gregor Mendel somewhat later, and published in 1866. Its full significance was not appreciated until the Modern evolutionary synthesis in the early 1920s.