Summary:
It is claimed that "survival of the fittest" is an empty tautology because the fittest are
defined as "those that survive", leaving us with the circular "survival of those that
survive". Far from being empty – this part of Darwin's theory makes substantive,
repeatable and testable predictions about events in the real world.
urvival of the fittest (SoF) is testable
Creationists commonly advance the tautology argument somewhat as follows: The theory of evolution
is built around the phrase "Survival of the Fittest" (SoF), but since the only measure of
fitness is the survival rate, this phrase actually reduces to "Survival of the
survivors" which is circular and thus an empty tautology. However, on examining this
argument we see that it is an attack only against the wording used to describe one of the core
concepts in evolution. It is not a challenge to the observable phenomenon to which SoF
actually refers.
SoF refers to the fact that given a certain selective regime in the real world, a population will
tend to evolve in the same direction over and over, and we can often predict in advance what the response
will be. For example, black moths will increase in frequency if trees are dark, and gray moths
will increase in frequency if trees are covered in gray lichen. It isn't just
"whatever survives survives"; it is that particular traits are preserved depending on
environment. Thus SoF isn't empty wording, it is a description of events in the real
world.
Historical introduction to the tautology argument
The tautology argument grew out of a change made by Darwin between
the fourth[1]
and fifth[2]
editions of his "On the Origin of Species". He changed the title of the fourth
chapter from "NATURAL SELECTION" to "NATURAL SELECTION; OR THE SURVIVAL OF THE
FITTEST" (SoF). He wrote: "This preservation of favourable variations, and the destruction
of injurious variations, I call Natural Selection, or the Survival of the Fittest", and
thereafter used the two terms as synonyms.
In 1879 Samuel
Butler[3]
charged that natural selection is a "truism",
leading to a focus on the phrase SoF and the assertion that because survival rates define fitness,
"'fittest' has no force" and thus natural selection and hence the whole of the
theory of evolution explains nothing.
Here, note that an attack launched against the phrase SoF immediately incorporates its synonym
"Natural Selection", despite the obvious fact that selection by nature is no more
tautological than selection by man. Thereafter, as usual, the attack is widened to include all
of evolution.
A current version of the tautology critique
A recent version of the tautology argument was made by Ann Coulter who said:
"The second prong of Darwin's "theory" is generally nothing but a circular
statement: Through the process of natural selection, the "fittest" survive. Who are
the "fittest"? The ones who survive! Why look – it happens every time! The "survival
of the fittest" would be a joke if it weren't part of the belief system of a fanatical cult
infesting the Scientific Community. The beauty of having a scientific theory that's a
tautology is that it can't be
disproved".[4]
Most creationists agree that the fittest survive
Note that the foregoing 'argument' characterizes as a "joke" the idea that it is
the best adapted (fittest) parents who have most offspring. So what do creationists propose as
an alternative? – that it is the worst adapted who are most fertile; that it is the arctic fox with
the shortest fur who fathers the most pups generation after generation?
No, apparently not; Coulter like many other fundamentalists, accepts that such adaptation occurs,
but denies that adaptation below the level of species (microevolution) is really evolution.
She says:
"Natural selection has never been demonstrated to change anything fancier than the shape of a
bird's
beak".[5]
"Evolution is not the capacity of bacteria to develop antibiotic resistance, but which never
evolves into anything but more bacteria. Evolution is not the phenomenon of an existing
species changing over the course of many years for example".
[6]
But this reveals a contradiction. SoF refers to only one element of evolution – the selection
process – not the entire theory. SoF refers to no aspect of "macroevolution"; not to
the creation of new species, or to the tree of common descent generated by speciation, or the nested
hierarchy of characteristics within that tree; nor does it refer to mutations as the cause of
variation. While supposing that Coulter, like many creationists, believes that all
characteristics are preloaded into the genome by design she also clearly knows that species do
change in response to changes in their environment. But such changes (like beak shape in
response to varying circumstances) are precisely the part of evolution that SoF describes!
So why are creationists arguing that a position they already accept is a "joke"?
Could it be they don't understand their own argument?
Survival due to specific characteristics
Coulter's argument asks: `Who are the "fittest"? The ones who survive!',
apparently a variant of "survival of the survivors", but it is not abstract individuals
who survive, but individuals with specific heritable characteristics. These characteristics
cause improved survival in predicable and often testable ways.
Specific heritable characteristics may include:
- visual sensitivity to yellow
- densest fur
- longest tail feathers
There is simply nothing tautological (in the circular sense) about survival of long tail
feathers. That "fitness" is intended to refer to specific characteristics is the
core to understanding that SoF is not in any sense a tautology, because by observation we can, for
example, establish that those arctic foxes with the densest fur survive to pass on that
characteristic. Similarly in a changing environment we may note that in dry years it is the
finches with the strongest beaks that survive, while in wet years those with the longest beaks are
retained. Hence, instances of SoF are clearly responses to changes in the real world, and
repeated failures to see the obvious reactions, would disprove SoF.
Sometimes survival isn't determined by fitness
Another problem with Coulter's argument is that it sets up full equivalence between survival and
fitness. "Who are the "fittest"? The ones who survive! Why look – it
happens every time!"(emphasis added). If that were true, then all differential
survival would necessarily be selection. But we have a name for differential survival that
isn't selection; it is called
drift
(basically, changes in a population's gene pool due to chance). And in fact we can often
perform tests that distinguish selection from drift. We couldn't do that if selection were
just "those that survive survive".
The tautology argument is an attack against wording, not substance.
The argument against "Survival of the Fittest" as a tautology is directed against the
formulation of that phrase, not the theory it describes. Darwin had previously been attacked
for the words "Natural Selection" when used to summarize his central idea. In reply
he wrote:
Others have objected that the term selection implies conscious choice in the animals which become
modified; and it has even been urged that, as plants have no volition, natural selection is not
applicable to them! In the literal sense of the word, no doubt, natural selection is a misnomer; but
who ever objected to chemists speaking of the elective affinities of the various elements?
– and yet an acid cannot strictly be said to elect the base with which it will in preference combine.
It has been said that I speak of natural selection as an active power or Deity; but who
objects to an author speaking of the attraction of gravity as ruling the movements of the planets?
Every one knows what is meant and is implied by such metaphorical expressions; and they are almost
necessary for brevity.[7]
So it seems entirely possible that Darwin would have agreed that SoF is, in the literal sense, a
"misnomer" or "false phrase", but he well knew that it is simply a descriptive
label or suggestive summary referring to one part of his theory.
Summary points:
- Survival of the Fittest (SoF) does not include many key aspects of evolution, like common
descent, the nested hierarchy, mutations, or speciation. What SoF does include is accepted
by most creationists as part of "microevolution". So why are they attacking a
part of evolution many of them agree with?
- In SoF, fitness cannot be equivalent to survival because characteristics generated by drift also
survive, thus SoF cannot be a tautology.
- SoF was intended to be a synonym for Natural Selection (NS), but NS is clearly not a tautology.
- SoF is a descriptive label referring to part of Darwin's theory. Attacking the label does
not challenge the theory itself.
- Fitness refers to specific characteristics, not some abstract and unknown generality, and so can
be tested against the real world. There is nothing tautological about survival of the
longest fur, longest tail feathers, or most bark-like coloration.
- SoF generates results that can often predict future events in the real world, such as the
results of further experiments, and is therefore not empty words.
Acknowledgements:
‡
This article was composed with valuable help and comments from:
John S. Wilkins;
El Cid;
Ivar Ylvisaker; Ernest Major; Burkhard; Ron Okimoto; Iain Inkster; J.J. Lodder; David Hare-Scott; Steven L.; and others
References:
[1]
Darwin, Charles, 1866. "ON THE ORIGIN OF SPECIES", Fourth Edition. London, John Murray, pp. 90
[2]
Darwin, Charles, 1869. "ON THE ORIGIN OF SPECIES", Fifth Edition. London, John Murray, pp. 91
[3]
Butler, Samuel, 1879 "Evolution, Old and New", Hardwicke And Bogue pp. 351
(first use must have been earlier since Darwin's colleague Alfred Russel Wallace was defending against the charge in 1873.)
[4]
Coulter, Ann, 2007. "Godless: The Church of Liberalism". Random House Inc. pp. 212-213, ISBN 978-1-4000-5421-3
[5]
Ibid., pp. 209.
[6]
Ibid., pp. 202.
[7]
Darwin, 1866., pp. 91-92.
Revision note:
†
The original 1997 version of this faq is here.
