This is an old revision of this page, as edited by Lexor (talk | contribs) at 09:19, 13 July 2004 (fmts: no longer a stub, fix casing on links and fix broken wikilinks, External Links -> External links). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Revision as of 09:19, 13 July 2004 by Lexor (talk | contribs) (fmts: no longer a stub, fix casing on links and fix broken wikilinks, External Links -> External links)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)This article describes the history of human thinkings on biological evolution and its extensions.
Pre-Darwin
Darwin
Charles Darwin formulated and published the first proper theory of evolution in 1858 and 1859, being a synthesis of earlier ideas.
Wilkins identifies Darwin's into seven categories:
- Transmutationism
- Common descent
- Struggle for existence
- Natural selection
- Sexual selection
- Biogeographic distribution
- Heredity
The modern evolutionary synthesis
The Williams Revolution
Universal Darwinism
Dennett (1995) argues that Darwin's dangerous idea was that algorithm that could be applied to any circumstances.
Recent developments in evolutionary theory
Symbiogenesis
Main article: Symbiogenesis
Another extension to the standard modern synthesis, advocated by Lynn Margulis, is symbiogenesis. Symbiogenesis argues that acquisition and accumulation of random mutations or genetic drift are not sufficient to explain how new inherited variations occur in evolution. This theory states that species arise from the merger of independent organisms through symbiosis. Symbiogenesis emphasizes the impact of co-operation rather than Darwinian competition. This commonly occurs in multigenomic organisms throughout nature.
Neo-structuralist themes in evolutionary theory
In the 1980s and 1990s there was a renewal of structuralist themes in evolutionary biology by biologists such as Brian Goodwin, that incorporates ideas from cybernetics and systems theory, and that emphasizes the role of self-organized processes as being at least as important as the role of natural selection. Some extreme variants consider natural selection as the result of biological evolution and not its cause, though most neo-structuralist biologists would not go this far.
The evolution of altruism
Main article: Altruism
Altruism has been one of the last (and most deeply embedded) thorns in the side of evolutionary theory, but recent developments in game theory have suggested explanations with an evolutionary context. If humans evolved, then so did human minds, and if minds evolved, then so does behaviour - including, according to these models, altruistic tendencies.
Theories of eusociality and the undoubted advantages of kin selection have made good progress in this direction, but they are far from unproblematic. Some writers have pointed out that the conscience is just another aspect of our mental behaviour, and propose an evolutionary explanation for the existence of conscience and therefore altruism. One recent suggestion, expressed most eloquently by the philosopher Daniel Dennett, was initially developed when considering the problem of so-called 'free riders' in the tragedy of the commons, a larger-scale version of the Prisoner's Dilemma.
An interesting example of altruism is found in the cellular slime molds, such as Dictyostelium mucoroides. These protists live as individual amoebae until starved, at which point they aggregate and form a multicellular fruiting body in which some cells sacrifice themselves to promote the survival of other cells in the fruiting body.