The concept of 'natural selection' still remains in general the response of populations to adapt to a changing environment. Though the concept has changed somewhat since Darwin proposed the Theory of Evolution. The science of Genetics was lacking when Darwin proposed the Theory now called the sciences of evolution. The following reflects a more contemporary view of some aspects of evolution and an interesting read concerning misunderstand among many that evolution is driven by 'random mutations.' Changing environments is the driving force behind evolution, and randomness has no role in the nature of our physical existence. Chaos theory and the fractal nature of the outcomes of cause and effect events is how things operate in our universe within the limits of Natural Laws.
By the way the sciences of evolution are not 'beliefs.'
Despite advances in molecular genetics, too many biologists think that natural selection is driven by random mutations
aeon.co
Since 1859, when Charles Darwin’s
On the Origin of Species was first published, the theory of natural selection has dominated our conceptions of evolution. As Darwin understood it, natural selection is a slow and gradual process that takes place across multiple generations through successive random hereditary variations. In the short term, a small variation might confer a slight advantage to an organism and its offspring, such as a longer beak or better camouflage, allowing it to outcompete similar organisms lacking that variation. Over longer periods of time, Darwin postulated, an accumulation of advantageous variations might produce more significant novel adaptations – or even the emergence of an entirely new species.
Natural selection is not a fast process. It takes place gradually through random variations, or ‘mutations’ as we call them today, which accumulate over decades, centuries, or millions of years. Initially, Darwin believed that natural selection was the only process that led to evolution, and he made this explicit in
On the Origin of Species:
A lot has changed since 1859. We now know that Darwin’s ‘gradualist’ view of evolution, exclusively driven by natural selection, is no longer compatible with contemporary science. It’s not just that random mutations are one of many evolutionary processes that produce new species; they have nothing to do with the major evolutionary transformations of macroevolution. Species do not emerge from an accumulation of random genetic changes. This has been confirmed by 21st-century genome sequencing, but the idea that natural selection inadequately explains evolutionary change goes back 151 years – to Darwin himself. In the 6th edition of
On the Origin of Species, published in 1872, he acknowledged forms of variations that seemed to arise spontaneously, without successive, slight modifications:
Today, we know in exquisite detail how these larger-scale ‘spontaneous’ variations come about without the intervention of random mutations. And yet, even in the age of genome sequencing, many evolutionary scientists still cling stubbornly to a view of evolution fuelled by a gradual accumulation of random mutations. They insist on the accuracy of the mid-20th-century ‘updated’ version of Darwin’s ideas – the ‘Modern Synthesis’ of Darwinian evolution (through natural selection) and Mendelian genetics – and have consistently failed to integrate evidence for other genetic processes. As Ernst Mayr, a major figure in the Modern Synthesis, wrote in
Populations, Species and Evolution (1970):
This failure to take account of alternative modes of change has been foundational to popular and scientific misconceptions of evolution. It continues to impact the study of antibiotic and pesticide resistance, the breeding of new crops for agriculture, the mitigation of climate change, and our understanding of humanity’s impacts on biodiversity.
Discoveries like hers should have inspired a radical rethinking of evolution
During the past century, discoveries that have challenged the gradualist view of evolution have been sidelined, forgotten, and derided. This includes the work of 20th-century geneticists such as Hugo de Vries, one of the rediscoverers of Mendelian genetics and the man who gave us the term ‘mutation’, or Richard Goldschmidt, who distinguished between microevolution (change within a species) and macroevolution (changes leading to new species). Their findings were ignored or ridiculed to convey the message that the gradual accumulation of random mutations was the only reasonable explanation for evolution. We can see the absence of other perspectives in popular works by Richard Dawkins, such as
The Selfish Gene (1976),
The Extended Phenotype (1982), and
The Blind Watchmaker (1986); or in textbooks used in universities across the world,
such as Evolution (2017) by Douglas Futuyma and Mark Kirkpatrick. However, it’s an absence that’s particularly conspicuous because alternatives to random mutation have not been difficult to find.
One of the most significant of these alternatives is symbiogenesis, the idea that evolution can operate through symbiotic relationships rather than through gradual, successive changes. In the early 20th century, American and Russian scientists such as Konstantin Mereschkowsky, Ivan Wallin and Boris Kozo-Polyansky argued that symbiotic cell fusions had led to the deepest kinds of evolutionary change: the origins of all cells with a nucleus. These arguments about symbiotic cell fusions, despite being vigorously championed by the evolutionary biologist Lynn Margulis in later years, did not find a place in evolutionary textbooks until they were
confirmed by DNA sequencing at the end of the 20th century. And yet, even though these arguments have now been confirmed, the underlying cellular processes of symbiotic cell fusions have still not been incorporated into mainstream evolutionary theory.
An interesting read more . . .
