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What Darwin should have learned from pigeons

Some have said of On the Origin of Species that it is all about pigeons.

Charles Darwin was fascinated by them. To help develop his thinking, he kept many different varieties and joined two local pigeon clubs to meet breeders. From one ancestral species, the rock-pigeon, hundreds of domestic breeds have been brought into existence. Darwin referred to the process as artificial selection: birds with desired characters are selected by the breeder for mating. Offspring with the strongest presence of desired characters are again selected for further breeding. By repeating the process, remarkable traits can be isolated, leading to characteristics that are novel and distinctive. Darwin wrote: ‘The diversity of the breeds is something astonishing’. However, his understanding of this diversity was seriously mistaken.

Breeder and environment

Crucial to Darwin’s thinking is that the ‘breed’ is just part of a continuum of variation. Beyond these are new species, new genera, new families, and so on. Apart from timescales, artificial selection was considered to be essentially the same as processes operating in the natural world. He wrote in his chapter on natural selection: ‘As man can produce and certainly has produced a great result by his methodical and unconscious means of selection, what may not nature effect?’ Instead of the breeder, we have the changing environment. Instead of intelligent and purposeful selection, we have unintelligent and unplanned processes that bring gradual changes to breeding populations of animals and plants.

To a large extent, this was Darwin’s direct evidence for evolutionary change (all the other evidences for his theory involved inferences from observation). With artificial selection, he could argue that his theory was supported by the routine practices of animal and plant breeders. Many have found these evidences very convincing. It is not unusual to find modern-day Darwinists pointing out that pigeons, or dogs (or some other animal group) provide us with real-time evidence of evolutionary transformation.

Misleading appeal

But Darwin was wrong — and so are his modern-day followers. Their appeal to ‘evidence’ is misleading. Even in Darwin’s day, the argument in the Origin was challengeable. Alfred Russel Wallace knew that domestic varieties tended to return to the wild type if they were released into the wild. His 1858 paper (accompanying Darwin’s to launch the theory of evolution by natural selection) argued against the ‘assumption, that varieties occurring in a state of nature are in all respects analogous to or even identical with those of domestic animals, and are governed by the same laws as regards their permanence of further variation. But this is the object of the present paper to show that this assumption is altogether false’. Wallace thought that artificial breeding provides no insight into the process of natural selection.

Nevertheless, the real challenge came from genetics. Gregor Mendel’s work unveiled information about heredity that was not discerned by Darwin. Today, we talk of dominant genes, recessive genes and multiple alleles. Breeders have found that hybridisation can unlock hidden variability and provide access to new recessive genes. The variability that so impressed Darwin was actually hidden, not new. So artificial selection cannot lead to new species, but only to specialised forms that are typically not viable outside the care of humans.

Eventually, genetics was linked to Darwinism by emphasising mutations rather than innate variability. Mutations were inferred to keep the theory alive. However, this has not provided a mechanism that is well supported by evidence: some of us have concluded that mutations deliver nothing but antibiotic resistance and non-viable oddities.

A dog’s life

Let’s apply this to dogs. Richard Dawkins claims that ‘domestic breeding relies upon exactly the same pool of mutational variation as natural selection’. This can be tested out, he suggests. ‘You’d take a wild species, say a wolf that hunts caribou by long pursuit, and apply selection experimentally to see if you could breed, say, a dogged little wolf that chivies rabbits underground: let’s call it a Jack Russell terrier.’ He goes on to refer to some other dog breeds — and, hey presto! — when the test is implemented, the results of breeding vindicate evolutionary theory. Dawkins claims victory: ‘I seem to hear mocking barks and deep, baying howls of derision from 500 breeds of dogs’.

Yet this enthusiasm for a Darwinian interpretation must be checked. The vast majority of these breeds are not associated with mutations. Those that are, like the xoloitzcuintli (Mexican Hairless Dog) and the pug, cannot survive without human care. The vast majority of the variations emerging from dog breeding come from innate variability and no new genetic information is involved. No new species have emerged: all these breeds are variants of Canis familiaris and all are genetically almost identical to the ancestral Grey Wolf (Canis lupus). All dogs, in principle, interbreed.

Caring for creation

The problems created by artificial selection came to a head in 2008 when the RSPCA withdrew from any association with the Crufts dog show. Concern was expressed regarding the diseases and deformities introduced by inbreeding. One vet commented: ‘This isn’t natural. They are not really viable breeds but are being artificially maintained. A lot would die if they were not treated. If it carries on like this, veterinary intervention will not be able to save some of them.’ When the limits of artificial selection are pushed, baying howls of derision turn into baying howls of suffering. Lessons are not being learned. Artificial selection should discard the delusion that there are no limits to variation and breeding programmes need to be intelligently designed to achieve sustainability. The best answer is a biblically-based understanding of genetics (linked to the separate creation of animal and plant kinds) and a biblically-based understanding of caring for creation (based on God’s commission to Adam and Eve in Genesis 1-2).

David Tyler