This blog may help people explore some of the 'hidden' issues involved in certain media treatments of environmental and scientific issues. Using personal digital images, it's also intended to emphasise seasonal (and other) changes in natural history of the Swansea (South Wales) area. The material should help participants in field-based modules and people generally interested in the natural world. The views are wholly those of the author.
Tuesday 28 June 2022
Natural Selection of Evolutionary Ideas?
The debate between acolytes of NeoDarwinism and a variety of Biologists now dissatisfied with this 'unifying' theory, seems to be getting quite exciting (https://www.theguardian.com/science/2022/jun/28/do-we-need-a-new-theory-of-evolution). It's pointed out that Darwin's idea of 'natural selection' (particular genes being favoured, over extended periods of time, by environmental factors) was once thought to be the 'key', to giving Biological Sciences a collective coherence. This, it was thought, would place it on a par with the 'laws' of Chemistry and Physics. This is challenged in at least two respects. The first challenge is the claim that Biology doesn't need a 'unifying law'. It's pointed out that the 'laws' of Physics and Chemistry (actually, simplier sciences) have exceptions and/or complicating factors. The second challenge is that some organisms can transform, by showing rapid 'heritable' changes. This is unlike the slow process of speciation envisioned by traditional NeoDarwinism. This is sometimes referred to as 'plasticity' or 'epigenetics'. Organisms have many genes. It is not unreasonable to suppose that which genes are activated and for how long, may be influenced by the organism's early experiences. This would enable such organisms to deal with a range of environmental challenges (like a drying environment or a different source of food provision). The whole process of sexual reproduction is geared to maximising genetic diversity. Meiosis (the form of cell division that produces the gametes), ensures that genes are effectively 'shuffled'. Some genes (including recent mutations) could be effectively 'held in reserve', before a later use is found for them? Certainly, evolutionary theory appears to be evolving.
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