Q. What about the Beak of the Finch?
Isn't this, as author Jonathan Weiner says, an example of "Evolution
in real time"?
A. The Galapagos finches occupy a special place in
Darwin's theory for they are claimed to demonstrate, in the words of writer
Jonathan Weiner, 'evolution in real time'. This dramatic claim is made because
Darwinists believe that they have actually observed the process of variation and
natural selection as it takes place in Darwin's finches on the islands -- in a
word, the process of speciation.
In the various islands in the Galapagos group there are said to be thirteen
species of finch. All these species are believed to be descendants of an
ancestral finch species and to have diverged in character to inhabit the
different ecological niches available in the islands, which are very remote,
some 600 miles from Ecuador, and thus provide an undisturbed natural laboratory.
Today's finches vary in their physical form (mainly the size and shape of
their beaks), their habitat and their diet, depending on which islands they
inhabit. On Daphne island, for instance, is a species called fortis with
a strong, thick beak for cracking nuts and seeds; while on Santa Cruz island is
a cactus finch scandens with a narrow fine beak, that feeds on insects.
Darwin arrived at the Galapagos in the Beagle in 1835. In his Journal of
Researches (popularly known as The Voyage of the Beagle) Darwin
famously commented that, 'in the thirteen species of ground-finches, a nearly
perfect gradation may be traced from a beak extraordinarily thick to one so fine
that it may be compared with that of a warbler. I very much suspect that certain
members of the series are confined to different islands.'
Darwin went on to add, 'Seeing this gradation and diversity of structure in
one small, intimately related group of birds one might really fancy that, from
an original paucity of birds in this archipelago, one species had been taken and
modified for different ends.'
These tentative statements contain all the main elements of Darwinism, then
and now: There are a multiplicity of 'species' with a generic similarity: they
live apart from each other and are 'confined' to different islands; they have
adapted to the differences of habitat on those islands; they represent a graded
series and look as if they have all descended from a common ancestor. These
facts alone invite us to draw the inevitable conclusion, without any further
evidence, that the finches represent an example of evolution by natural
selection. And that is precisely the conclusion Darwinists have drawn for 130
years.
Ornithologist David Lack visited the islands in 1937 and stayed through one
breeding season. He built cages and tried to encourage the thirteen 'species' to
mate, noting that they were reluctant to mate and did so only 'rarely'. Lack
also noted in his monograph, Darwin's Finches 'In no other birds are the
differences between species so ill-defined.'
Lack drew up maps of the islands, showing the distribution of the thirteen
species. His maps showed that either one species had come to dominate each
island, or that two main species were in competition there.
When he returned to England with his data, apparently showing the possibility
of natural selection at work he was urged by Julian Huxley to publish as soon as
possible because his work would help establish the acceptance of Darwinian
processes.
Lack's work was incorporated into the flourishing theory of neo-Darwinism
throughout the 1950s and 1960s and Darwin's finches became as familiar to
students as the melanic form of the peppered moth.
Lack was followed by the husband and wife team of Peter and Rosemary Grant
who have lived and worked on the Galapagos islands from 1973 to the present. The
Grants and their co-workers have been the first people to study the beaks of the
finches in detail. They have shown how a difference of half a millimetre in the
length of a beak makes the difference between life and death for the finches
during a drought.
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Jonathan Weiner wrote that; 'Among fortis, [the Grants] already knew
that the biggest birds with the deepest beaks had the best equipment for big
tough seeds ... and when they totted up the statistics, they saw that during the
drought, when big tough seeds were all a bird could find, these big-bodied,
big-beaked birds had come through the best. The surviving fortis were an
average of 5 to 6 per cent larger than the dead. The average fortis beak
before the drought was 10.68 mm long and 9.42 mm deep. The average beak of the fortis
that survived the drought was 11.07 mm long and 9.96 mm deep. Variations too
small to see with the naked eye had helped make the difference between life and
death.'
This is indeed convincing. Tiny, imperceptible differences in beak shape are
the difference between survival and extinction. From the point of view of
Darwinian evolution however, the question is rather different: can such
differences lead to changes from one species to another?
As observed earlier, the force of these findings depends entirely upon the
question of whether the thirteen species really are different species or merely
variations of the same species of finch. To determine this, according to the
accepted biological definition, we must find out if they mate and bear fertile
young but are reproductively isolated.
David Lack tried to observe a finch of one species pairing off with another
but did not find a single case. He reached the conclusion that 'Clearly
hybridization between species is rare, if not absent.' This conclusion was of
crucial importance to Darwinists like Huxley because it proved that the
different finches were indeed different species. And this, in turn made it
likely that, far from outside influences, they had diverged from a common
ancestral species by natural selection in the perfect experimental setting of
the Galapagos.
If Lack's observation is true, then Darwin's conjecture may also be true. If
it is not true, then Darwin's idea is deprived of any content. For if all the
finches on the Galapagos are merely members of the same species, then there is
no meaningful sense in which they can be held up as an example of 'evolution in
real time'.
On this key issue, Jonathan Weiner seems entirely unconscious of the
scientific significance of his own reporting. In his Pulitzer Prize winning
book, The Beak of the Finch, he wrote; 'Back in 1983, for instance ... a
male cactus finch on Daphne Major, a scandens, courted a female fortis.
This was a pair of truly star crossed lovers. They were not just from opposite
sides of the tracks, like the Prince and the Showgirl, or from two warring
families, like Romeo and Juliet: they belonged to two different species. Yet
during the chaos of the great flood, they mated and produced four chicks in one
brood.'
Not only did the finches in question mate successfully, their offspring
proved to be among the most fertile that the Grants recorded during their twenty
years on the islands. The four chicks of this mating produced no less than 46
grandchildren.
The Grants recorded many other pairings of 'different species' of finch,
which, like Lack before them, they dubbed 'hybrids'. But of course the central
significance of this finding is that the identification of the thirteen
varieties as different species is impossible to maintain once it is admitted
that they can interbreed and produce fertile young.
The fact that different varieties prefer not to mate is very different from
saying that they are unable to do so. Great Danes do not usually select toy
poodles as potential mates (and vice versa) but they are capable of bearing
fertile young if mated and are members of the same species, Canis familiaris.
Arab stallions do not normally select Shetland ponies as mates, but they are
members of the same species, Equus callabus.
Moreover, the Grants' observations undermine another myth about Darwin's
finches - that individual species are 'confined to certain islands'. In order
for different species to mate, they clearly have to occupy the same territory.
Other visitors to the Galapagos have confirmed that this is this case.
Television documentary filmmaker Gillian Brown spent a year working at the
Darwin Research Station on the islands. It is common, says Brown, to find the
different species all over the archipelago, rather than obeying the colored
territorial maps drawn up by Darwinist ornithologists.
In almost all respects, the finches of the Galapagos are so similar that it
is difficult to tell them apart. Indeed, Weiner himself remarks that, 'Some of
them look so much alike that during the mating season
they find it hard to tell themselves apart.' This mirrors David Lack's
observation that 'In no other birds are the differences between species so
ill-defined.' The finches all have dull plumage, which varies from light brown
to dark brown, all have short tails, all build nests with roofs, and lay white
eggs spotted with pink, four to a clutch.
It is very difficult for an objective observer to see how a group of finches
who 'find it hard to tell themselves apart', and who do in fact interbreed, can
legitimately be called different species.
What is the scientific basis of this identification?
