Acquired characters, inheritance

Jablonka, E., Lachmann, M. and Lamb, M.J. (1992) Evidence, mechanisms and models for the inheritance of acquired characters. Journal of Theoretical Biology 158, 245-268. 

Lamarck recognized a similar principle of evolution referred to as inheritance of acquired characters, stating that variations in character-istics seen in organisms were acquired in response to the environment. 

Together with the problem of evolution, however, Lamarck also addressed the problem of its mechanism, and here he made hypotheses that turned out wrong, and for which he has been reproached ever since. Lamarck s mechanism (or, rather, what has become known as such) comprises (1) spontaneous generation, (2) an intrinsic tendency towards complexity, and (3) the inheritance of acquired characters. Today all these concepts are rejected, but the reasoning that brought Lamarck to proclaim the reality of evolution is independent of them and remains perfectly valid. 

The physical separation between genotype and phenotype has an extraordinary consequence, because mental genotypes can be directly instructed by mental phenotypes, and this means that cultural heredity is based on a transmission of acquired characters. Cultural inheritance, in other words, is transmitted with a Lamarckian mechanism, whereas biological inheritance relies on a Mendelian mechanism which is enormously slower. As a result, cultural evolution is much faster than biological evolution, and almost all differences between biology and culture can be traced back to the divide that exists in their hereditary mechanisms. The discovery that human artifacts (i.e. cultural phenotypes) obey the Lotka-Volterra equations has two outstanding consequences. The first is that selection accounts for all types of adaptive evolution natural selection is the mechanism hy which all phenotypes - biological as well as cultural - diffuse in the world. 

It must be said at once that this programme of inquiry can hardly be implemented at the present time and will certainly not be pursued very far in the present account. Nevertheless, the form of it is to be observed, since it helps to place in perspective a question which arises at quite an early stage in the study of single cells, namely that of the inheritance of acquired characters. 

But from what has been said there seems to be no good reason for this conclusion. The non-inheritance of acquired characters could be very naturally explained by the screening of the genes of complex animeds from environmental influences rather than by their complete immutability, and a chemical theory of changes in bacterial, cells would then cease to appear in any way heterodox. At any rate we shall state briefly some of the aspects of such a theory. 

Waddington CH (1942) Canalization of development and the inheritance of acquired characters. Nature 150 563-565... 

Factor 2 Fault of person. In this factor, it is assumed that negative character traits (whether acquired or inherited) such as violent temper, excitability, ignorance of safety-related practices, recklessness, and nervousness constitute proximate reasons to commit unsafe acts or for the existence of mechanical or physical hazards. 

Negative character traits leading a person to behave in an unsafe manner can be inherited or acquired as a result of the social environment... 

Ancestry and social environment In this factor, it is assumed that negative character traits such as recklessness, stubbornness, and avariciousness that might lead people to behave in an unsafe manner can be inherited through one s ancestry or acquired as a result of one s social surroundings or environment. 

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