Myths of Evolution (3): Only the Strong Survive

Only the strong survive? Tell that to the dinosaurs. The rajasaurus pictured here lived at the very end of the Cretaceous period and despite its power, it and dozens of other carnivorous therapods were destined for extinction.

The idea that strength is the most prevalent survival trait is not even remotely based upon scientific observations, and draws primarily from people's beliefs about competition. But even accepting the rather limited view that competition is the sole aspect worth focusing upon (mistaking ubiquity for quintessence), strength is just one of many competitive advantages that can help a species survive (or indeed, an individual succeed).

The mythology behind the idea that “only the strong survive” relates not so much to biology, but rather to sociological metaphysics. The idea is associated with social Darwinism, which represents a range of different ideologies with very little in common beyond the belief in competition as the driving force in cultural evolution. The term is quite misleading, as it refers to many things which were formulated before Darwin published On the Origin of Species by Means of Natural Selection, including the ideas of the 18^th century clergyman Thomas Malthus, as well as those of Darwin's cousin Francis Galton.

The trouble with social Darwinism is that it is entirely metaphysical – there is nothing testable in the idea of the primacy of competition, and it has lamentably been used to fuel all manner of abhorrent ideologies such as imperialism and racial supremacy. As we saw in the previous myth of evolution, luck has just as great a role in influencing biological evolution as strict competition, and the same is likely true in the social realm. Furthermore, it is readily apparent that even recognising numerous aspects of competition in society doesn't preclude a parallel recognition of the benefits of co-operation: if companies compete in the national marketplace, and nations compete in the international marketplace, it is important to remember that both the company and the nation represent examples of widespread co-operation. If this were not the case, all trade would be between individuals.

Returning to biology, and accepting the simplification briefly, we might say that the strongest (i.e. deadliest) species generally become top predator within a particular ecology – but survival for apex predators is extremely precarious. Animals in such a position depend upon the robustness of the entire food web they are embedded within for their survival. A fox may be stronger than a rabbit (in terms of the capacity to cause harm), but if something threatens the survival of the rabbit, the fox is equally threatened: predators (which we tend to think of as being “strongest”) inherit vulnerability from the species they prey upon when ecological equilibrium is lost. Rather than generating survival advantage, they actually suffer extreme disadvantages in survival during times of crisis, precisely because they are dependent upon the success of their prey species. Few predator species rack up more than a few tens of millions of years at the top before becoming extinct.

If you want to pick out in the abstract the trait most suited to long-term survival of a species (and even more so for a chain of successive species), it is not strength but adaptability. The bigger and stronger you are, the fossil record attests, the harder you fall. At the end of the reign of the dinosaurs, some 65 million years ago, it was the tiny yet adaptable mammals that gained the edge (roughly 10 of the 15 mammal families at the end of the Cretaceous survived), along with some of the smaller, more adaptable therapod dinosaurs, which diversified into modern birds. Being strong only gets you as far as the next cataclysm: being adaptable is a far safer long-term strategy.

Alternative myth: Survival of the Adaptable

Next Week: Myth #3: The Selfish Gene

Comments

[Peter Crowther]

Sorry Chris, I disagree with the premise of this article. I believe you are looking at this myth at an inappropriate grain.

Consider instead competition between individuals within a species (or, even more interestingly, a niche) rather than between species. At that level, the "fittest" (for the appropriate environmentally-defined fitness function, which is unlikely to be pure strength) have a selection advantage.

I suspect the myth arose because "strong" is one antonym of "weak", and the weak/sick individuals in a population typically are at a selection disadvantage. Note that this is a biological origin, not a social one.

[Chris]

Peter: But even within a particular species or niche, the most appropriate mythology to attach is still not "only the strong survive".

In beetles, the most prevalent non-microscopic organism on our planet, the beetles of any given species which prosper are rarely if ever stronger than their kin. Of course those with serious defects are culled, but the competition between beetles happens only in beetle fights which do happen, but are rarely central to the natural history of beetles. In fact, survivability for beetles depends more upon their ability to avoid predation than their strength relative to one another, in common with many insect species. You can call this "strength" but I see this term as highly misleading.

In barnacles, "strength" is a factor in so much as they have to hang on to their rocks (or ships) but there is not a significant differential of strength between barnacles (if you don't believe me, try attempting to find a "weak barnacle" that you can pull off the rock!) In fact, the accuracy of their prehensile penises is more a factor in propagation of barnacles. I don't think this corresponds with the term "strength" very well.

In bowerbirds, strength is a long way off the agenda, as the males compete to build elaborate nests (known as bowers) to attract mates. Competition, yes, but you could not claim that strength was a factor in this particular competition!

Notice that in all three cases above, where competition occurs it is not competition for survival but competition for mating. So I maintain my claim that "only the strong survive" is a lousy myth to attach to evolutionary theories, especially in the role of an "umbrella story".

Now you want to defend it by saying that it's just trying to say "survival of the fittest". Well that's my fifth and final myth of evolution, so we'll get to that (and I am sure you shall object to this one too!) :)

You want to make the claim that "strength" stands in for "best adapted to their niche", I suppose - well then, how is this not compatible with my alternative myth "survival of the adaptable"? Those species that were best able to adapt to their niches fielded individuals best suited to survive in those conditions.

If you want to switch the original myth of this piece to "the weak are disadvantaged", that would be an improvement I suppose (although it makes for a dull story), but "only the strong survive" is incorrect in asserting "strength" as the key factor, in linking "strength" to "survival", in conflating survival and mating advantage, and in excluding alternative factors with the word "only". I say we should ditch this myth and move on. :)

Best wishes!

[Peter Crowther]

But even within a particular species or niche, the most appropriate mythology to attach is still not "only the strong survive".

I agree with you that it's inappropriate; I was merely challenging the grain at which you were writing about the subject, which appeared to be at the species level, and offering an alternative to your assertion that "[t]he mythology behind the idea that “only the strong survive” relates not so much to biology, but rather to sociological metaphysics."

[Chris]

Peter: yes, I see the nature of your clarification here. I look forward to your critique of my attack on "survival of the fittest" in a fortnight's time. :)

[Larry]

Mans observations of nature interprets nature to have laws (absolute truths}…
One conclusion which again is subject to interpretation is “only the strong survive”.
I believe there is confusion in interpreting the definition of strength. In the game of
Rock, Paper & Scissors, which one is the strongest? Does not a one celled animal
(microorganism) have the capability to take down a pack of lions?
What is even more puzzling is man’s constant rebellion to what they believe to be
the natural order of things. As they observe nature and conclude only the strongest
of species will survive they attempt to shore up the weak. Is it fair to observe nature
without including man’s behavior in their observations.
After observing Nature’s law one’s hypothesis should be “ONLY THE ADAPTABLE WILL SURVIVE”. However, it seems that the majority of society feels adapting has weak connotations and prefer words like strength, backbone, force, fortitude and power.
Most would rather fight than adapt! ODD?!

[Chris]

Larry: Yes, it's a strange phenomena to be sure, but of course what is likely happening is people have a prior commitment to forceful competition, and then can adapt the interpretations of natural history to shore up this belief. It is the nature of beliefs that we can always find evidence to support them. :)

Thanks for your comment!

[Larry]

“As we saw in the previous myth of evolution, luck has just as great a role in influencing biological evolution as strict competition, and the same is likely true in the social realm.”

With our limited capabilities (i.e. our inability to analyze the infinite amount of variables in order to arrive at a conclusion deemed absolute) let us examine the word “luck”. To
quote a dictionaries’ definition: a combination of circumstances, events, etc., operating by chance to bring good or ill to a person. For those who are swayed by the chaos theory, any words relating to chance is digestible. However, those of the intelligent design persuasion may have deleted those words (i.e. luck, chance, random, etc.) from their vocabulary. Should more thought be directed into a theory of predestinated evolution?

[Casey Hutchens]

What i think is that microrginism's are little micro-people, say we are them, them are we... do you see..?? they build there army up and try and think of new ways to figure out how to destroy us ( the human race).We study them, and look at there biology. So my theory is that they are people. We are there enemies and all those other flu's, mysteriosly come up out of no where and start killing off the "weak" aka darwins law.. only the strong survive.. so there is my theory... but it sounds crazy.. :) but please email me and what you think of that...

[Chris]

Larry: very sorry I didn't see this comment of yours earlier! It must have slipped by when I was leaving for the US on the last trip.

I do think that if people want to influence the Young Earth Creationists towards accepting evolution, it would be necessary to do so theologically - I've been pondering writing something in this vein for a while now, actually, but have held back because, frankly, anyone who has chosen to base their epistemology solely on the Bible isn't going to be swayed by theological arguments! :)

I do feel in general terms that theists must inevitably sway towards predestined evolution, as you suggest here. I think this is how many Christians have come to accept evolution - as part of God's plan. The Young Earth Creationists are effectively blocked from this kind of rationalisation by their idolatry of the Bible. On the whole, I find this quite ironic!

Casey: Sorry, I don't send out emails in response to comments but in brief I would say since we are colonies of micro-organisms your perspective has its merits! :) But it would be a mistake to believe the other micro-organisms intend to destroy us - most of them peacefully co-exist with us, and many provide symbiotic benefits. It's always a few bad apples that ruin it for everyone else. :D

Thanks for the comments!

[Casey Hutchens]

well of course we have our allie's and non allies.. we are microscopic fungus :p

[Ken]

Yes tell that to the dinosaurs. Do you think no organisms survived the fallout. Alligators are dinosaurs they are still here.

[Chris]

Hey Ken,
Not quite sure who or what you are responding to here... technically, alligators and crocodiles aren't dinosaurs since the former are the order Crocodylia, while the latter are Dinosauria. But you're right, of course, that the crocodilians survived the end of the Cretaceous (as did other reptile species, of course, most obviously snakes).

Personally, I do tend to think of the crocodilians as dinosaurs, as well as the pterosaurs (which are similarly 'not dinoaurs' on a technicality), but only because I like to take 'dinosaur' in a broader way than its technical usage.

Thanks for commenting!