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Different levels and kinds of selection?

Another area of intense debate concerns the primacy of purely ‘Darwinian’ gene-based natural selection. One important difference between Darwin’s theory and those which had been proposed before, such Lamarck’s, is the mode of inheritance. Where Lamarck allowed for the inheritance of characteristics acquired during an animal’s lifetime, Darwin realised that the inheritance of traits seen in commercial animal breeding was sufficient to enable natural selection and evolution. The integration of Mendelian genetics into evolutionary theory in the 1930s provided a clear endorsement of Darwin’s intuition. Inheritance was explained in terms of the transfer of genes from parent to offspring, so only those traits that could be encoded in genes would be preserved. Furthermore, the ‘central dogma’ of cell biology states that information cannot flow from the organism to the gene. This means that the only unit of natural selection is the gene, and in theory the entire ‘epic of evolution’ can be expressed as a history of changes in gene-frequencies. This account is a triumph of reductionism.

Richard Dawkins produced a masterful account of evolution in these terms in his 1976 book The Selfish Gene. There have been ongoing discussions concerning his use of the word ‘selfish,’ but it did make his message clear: evolution occurs at the level of genes. This dogmatic understanding of evolution is essential if Darwinian natural selection is to remain the sole explanation for the origin and adaptation of species. However, from early on it was clear to Darwin that selection may occur in other ways as well. The debate over possible ‘levels of selection’ and different kinds of selection is still very much alive.See Dennett, Darwin's Dangerous Idea: Evolution and the Meanings of Life 57-59, 126. Conway Morris goes so far as to say that “claims for the primacy of the gene have distorted the whole of biology.”Conway Morris, Life's Solution: Inevitable Humans in a Lonely Universe 238.

Most arguments challenging a purely gene-centric view of evolution point to the Baldwin effect. In 1896 James Mark Baldwin wrote a paper on ‘A New Factor in Evolution’ arguing that the relationship between environment and organism was not fully captured by a purely Darwinian explanation. While it is true that organisms adapt to become fit in a given environment, mobile organisms can seek out different environments. At a minimum, Baldwin’s proposal suggests that offspring inherit more than genes from their parents; they also inherit the environment into which their parents bear them and any disposition they may have to travel to more favourable environments. In other words, the door is open for adaptive behaviour to be inherited.

It is conceivable that behaviours can be encoded in genes, but they can also be learnt through mimicry.See Ian G. Barbour, Religion in an Age of Science (London: SCM, 1990) 157. If learnt behaviours are afforded a role in evolution then we have left the realm of pure gene-based Darwinism. It is true that Darwin’s mechanism of natural selection can be expected to operate in any system that has replication, variation and some measure of fitness. As such, it can be applied to the development and transmission of behaviours, ideas and culture. But behaviours and ideas are far more fluid than genes, and the concept of fitness is once again problematic. Dawkins developed the idea of the ‘meme’See chapter 11 of Richard Dawkins, The Selfish Gene (Oxford: Oxford University Press, 1989). See also Dawkins on cultural evolution: Dawkins, The Blind Watchmaker 216. and attempted to show how Darwinian ideas could be applied to culture, but it has acquired few advocates.Two supporters that should be mentioned are Julian Huxley (predating Dawkins’ use of the term meme) and Daniel Dennett.

Darwin himself came to the conclusion that “Natural Selection has been the main but not exclusive means of modification.”Darwin, The Origin of Species by Means of Natural Selection: Or, the Preservation of Favoured Races in the Struggle for Life 69Ruse represents the current situation as follows: “A Darwinian has to regard natural selection as the most important evolutionary mechanism that there is. ... There is disagreement over how important “most important” really is.”Ruse, Can a Darwinian Be a Christian? The Relationship between Science and Religion 28. The debate over higher levels and kinds of selection continues, however, it is likely that we will see the distinction between ‘ultra-Darwinism’ and the broader concept of evolution grow. It may be that natural selection and Darwin will come to occupy positions analogous to gravitation and Newton in physics; i.e. central, but just part of a much larger picture.

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Go to Evolution Topic Index

Different levels and kinds of selection?

[1] Does Evolution ‘do the work of a friend’ for the Christian Religion?
Setting the scene - why focus on providence?
[2] Supposed challenges from the evolutionary sciences to theology
Intellectually fulfilled atheists?
A challenge to human uniqueness and status?
A challenge to purpose in creation?
A threat to the veracity of scripture?
Evolution ‘explains away’ theology?
A challenge to Christian morality?
The challenges in wider context - Darwin as a scapegoat?
[3] The current state of the evolutionary sciences
Different ways of conceptualising Darwinian evolution
Evolution as chance and necessity
Evolution as an algorithm
Evolution as movement within a ‘fitness landscape’
Ongoing debates: contingency versus convergence
Ongoing debates: what are the key causal factors in biological history?
Ongoing debates: the environment as the principle cause?
Ongoing debates: convergence as the principle cause?
Ongoing debates: ‘Universal biology’ as the principle cause?
The importance of moving from evolution as abstraction to particular history
Ongoing debates: directionality and progress
Ongoing debates: the origin of life
[4] Responses from theology
Evolution, probabilities and providence
Responses from contemporary theologians
Holmes Rolston III
Keith Ward
John Haught
Arthur Peacocke
An increased role for general providence?
Theology of Creation in the light of evolution: three scenarios
[5] Concluding remarks
Sources

Source:

Adrian Wyard
Adrian M Wyard MSt

See also:

Evolution
The Relation of Science & Religion
Purpose and Design
Genetics
The Argument From Design
The Anthropic Principle
Opinions
Charles Darwin
DNA Double-Helix