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pleiades's avatar

As it purely pertains to science, what does, "Survival of the Fittest" mean?

Asked by pleiades (6175 points ) February 6th, 2014

As asked. Please cite examples!

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37 Answers

ragingloli's avatar

Survival of the one who is best adapted to the environment it lives in.
Example: Penguin vs Lion.
Easy you might say, right? The lion has sharp teeth and claws, and is faster, stronger and smarter than the penguin. So the lion should completely trounce the penguin, right?
But if you drop them both in the antarctic, the lion will die, and the penguin will survive.

janbb's avatar

@ragingloli Indeed, you are correct!

rojo's avatar

I would add: and have the ability to pass on the adaptive traits/genetic makeup though their offspring.

A feathered/finned lion/penguin crossbreed might be predisposed to survive the cold while feeding on penguins but if it is infertile, the traits will die out.

Skaggfacemutt's avatar

I didn’t take it that way at all. I understand this phrase as meaning that the stronger specimens in any species have a better chance of survival than the weaker specimens of the same species. Factors that would make an animal a “sitting duck” would be the very young, the very old, the wounded or handicapped, those with birth defects or genetic defects, Some animals even deny food and protection to those amongst them that are weak or defective, because it is nature that the group would not waste resources on a member that is unlikely to survive, or be much of an asset.

Coloma's avatar

@Skaggfacemutt I agree, adaptive advantages aside it would also encompass the age, health and strength of an organism within its own species.

rojo's avatar

@Coloma, @Skaggfacemutt I don’t feel you can put adaptive advantages aside. It is adaptations that make the animal what it is. A young, solid colored faun is at a disadvantage over a mottled one because it stands out more and is more likely to be seen and not make it to adulthood thus not pass on the solid coloration. I think this is the main reason traits such as albinism are not common.
Same goes for the very old; there is a reason that they attained that old age and they have probably already passed on these genes. Handicaps also reduce survival rates/breeding chances; same with illnesses; those predisposed to disease either die of the disease or are easier killed.
Same for the bigger/stronger. How did they get that way? Because their progenitors passed on the genes that made them what they are? Why? Again because whatever it was gave them some advantage over others of their species.
Admittedly that is not always that way, weaker genes slip in because fate also plays a hand in the game.

pleiades's avatar

I agree with @ragingloli @janbb because it is who ever is most well adapted to their environment at any given time who is the “fittest” ergo, “best fit for the environment” I think the common misconception is the example @Skaggfacemutt states which is basically talking about a certain population and out surviving the competition when really it’s the physical environment first that is the hugest factor as to whether or not that species is equipped to live through the said environment.

Coloma's avatar

@rojo Okay, retraction, agreed, however regardless of adaptation it still boils down to the individual organisms strength, survival success and resiliency to disease, wounds and savvy.

rojo's avatar

True, all of which boil down to its genetic make-up. (Ok, not the wounds, although an argument could be made that they would not have received the wounds had they been quicker, smarter or better equipped).

flutherother's avatar

How do we define the fittest? Is it the biggest, the most aggressive, the most intelligent, the most able to withstand heat or the most able to withstand cold? It could be any of these. The only meaningful definition is that the fittest are those that are best able to survive and so the phrase means nothing in a scientific sense.

rojo's avatar

@flutherother as @ragingloli indicated, in a given environment. It has to be in context.

Those best adapted, adjusted, qualified, or suited to some purpose, function, or situation survive; those not, don’t.

flutherother's avatar

@rojo That’s true, but nonetheless there can be a tremendous diversity of creatures living together in a particular environment. Look at the rain forests for example. “Survival of the fittest” suggests a bloodbath with one survivor but you don’t see that in Nature red in tooth and claw though it may be.

janbb's avatar

@flutherother I think it’s the fittest within any of the species that are adapted to that environment; intra rather than inter-species..

Dutchess_III's avatar

Well, I’ve always thought it to also mean that among a species, if there is a mutation in one animal that has a distinct advantage, that individual will live to create offspring that carry that positive mutation, while the ones who don’t have it slowly fall behind.

It’s kinda like how humans got to the top of the food chain in spite of having NO natural weapons such as claws and teeth and it’s how we can adapt to virtually any environment. Although I hate my current environment cause it’s SO damn COLD!

glacial's avatar

As it pertains purely to science, most of you have no idea what you are talking about. Fitness is not strictly about being stronger or better or what adaptations you have. It is about how many offspring you are leaving, relative to individuals that do not have the adaptations that you do. It is a thing that can be measured. Here’s the requisite Wikipedia page: http://en.wikipedia.org/wiki/Fitness_(biology)#Measures_of_fitness.

Why are people talking about “how I see it” or “I don’t feel”? There are definitions for these things. They are not matters of opinion.

Dutchess_III's avatar

Well, my definition was pretty close, @glacial.

rojo's avatar

@flutherother I disagree that you would have to find or have a “bloodbath”. Each species conforms to its owe needs, some herbivores eat the grasses, some the bushes, some the shrubs, some the tree leaves. You have insectivores, carnivores that eat smaller animals, carnivores that eat medium sized animals and some that eat larger ones. Then there are those that live on scavenged food, Each has its niche that over the millennia they have adapted to fill in order for the species to survive and each can and do live along side the others.
If a particular food source is eliminated, the species must adapt or die. Hopefully there will be some genetic predisposition that will facilitate survival of some individuals.
If all the grasses disappear, those that depend on them will be hard pressed to survive but if there are a few who can process coarser materials such as leaves they will stand a greater chance of surviving and passing on their genes through their offspring.

The belief that it is the strongest, meanest, most violent are the most fit to survive that leads to such myopic ideas as Social Darwinism.

gorillapaws's avatar

Fitness is all about your ability to pass on your genes to future generations. In some cases it may be indirectly as it may be more beneficial to sacrifice yourself to insure several of your relatives survive despite not reproducing directly.

LostInParadise's avatar

@glacial , It may not be that simple. There is a debate going on among biologists whether selection occurs only at an individual level or if it can also take place at a population level, particularly with regard to altruism. The equations you cite are still applicable, but the mechanism may be indirect. A genotype that results in very aggressive individuals may be highly successful in reproducing successive generations of aggressive individuals, but the population as a whole may suffer. By contrast, a genotype that results in altruistic behavior may assure its survival by helping to promote the survival of the entire local population.

rojo's avatar

Humans are actually a good example of this. We are not the swiftest, strongest nor the most armed members of the animal kingdom. We are slow, soft, smelly, squishy things with small teeth, limited olfactory skills and no claws yet because of our ability to adapt, through our perspicacity and production of cultural artifacts, we are able to survive and thrive in almost any environment on the planet.

We are pretty good at the bloodbath thing though.

Coloma's avatar

Today only the best drivers will survive the rain slick freeways over here. I plan on being one of them. Doesn’t hurt to have a really solid and excellent handling car either.
Car accidents are the modern way of weeding out the inferior of the species. lol

Dutchess_III's avatar

And boy there are a lot of them @Coloma!

flutherother's avatar

@rojo That was my point, you don’t see a bloodbath in Nature and you don’t see survival of the fittest either. You do see the non survival of the least fit but that is a bit different. Life prospers and evolution produces a variety of fit creatures.

The concept of a ‘fittest’ creature is a man made concept that usually means Man himself and is not a concept that Nature recognises. What you find in Nature is harmony between hunter and prey and co operation within species. That would make a truer and a better model for Man than ‘survival of the fittest’.

Dutchess_III's avatar

There is no more “cooperation” between species than that displayed by man toward other species. Hundreds of examples of that. Saving stranded whales and dolphins is one example. Saving animals, such as wolves and tigers, that would be considered natural enemies in nature is another.

Other species cooperate at times, but not to the extend that man does.

Skaggfacemutt's avatar

Wow, I just read (or tried to read) the Wikipedia article that @glacial posted above. Leave it to the scientists to take a simple concept and make it as insanely complicated as possible. Scientists continually try to weigh, measure, and define things that are not weighable, measurable or definable, such as survival of the fittest. According to the scientific definition,the ability to pop out babies just like themselves is the only yardstick to fitness. According to science, housecats would never have a better chance of survival than lions, but science doesn’t take into consideration the tendency of humans to kill lions and pamper housecats. Who would think that a mouse would have a better chance of survival than a t-rex. The t-rex spent millions of years adapting to it’s environment and was a survival machine – but then the environment suddenly changed, and the t-rex was too specialized to survive. Their adaptations are what did them in – a need for massive caloric intake and tons of oxygen-rich air to support their massive size.

I really like @flutherother ‘s comment – the non-survival of the least fit. That is a much truer statement, that could pertain to both species-against-species and to inter-species contests.

Dutchess_III's avatar

They were too big to survive, @Skaggfacemutt. I read somewhere that anything over 50 pounds didn’t survive the blast.

Skaggfacemutt's avatar

That’s what I said – their size did them in on many levels.

glacial's avatar

@Skaggfacemutt “According to science, housecats would never have a better chance of survival than lions,”

I have no idea what this is supposed to mean. It sounds like you are saying that if you hold a cage match between a housecat and a lion, the lion should win. That has nothing to do with fitness in the evolutionary sense. Housecats and lions do not live in the same environments, they do not compete for the same resources, and they do not face the same dangers. They cannot be compared in this way. You say that you read the Wikipedia page that I posted, but you don’t seem to have understood the point. You call fitness a simple concept, but you don’t seem to have grasped it.

This is the same problem we encounter when people say “Evolution is just a theory.” You’re using a word that has a scientific meaning as if it means the same thing that it does in everyday common language. It doesn’t.

I can go to the gym and get very fit, or I can grow very tall or I can have perfect vision, or a useful prehensile tail, but if I never have a child, then evolutionarily speaking, my fitness is zero, zilch, nada. If you pass on more of your genes to the next generation than I do mine, then you’re fitter than me, even if you weigh 400 pounds and can barely walk.

@LostInParadise Sure, you can have indirect fitness through kin selection. But when people are struggling with the very simple difference between “being strong” (which is not fitness) and passing on genes (which is), that explanation is where I’m spending my energy.

LostInParadise's avatar

@glacial, Kin selection is not the same as group selection. E O Wilson caused a major stir among biologists when he dropped his former emphasis on kin selection and instead advocated the importance of multilevel selection. The debate continues among biologists. Personally, I love the idea that different levels of abstraction take on a life of their own.

janbb's avatar

Surely fitness means the ability to survive in one’s environment as well as the ability to pass those adaptive genes on to offspring, doesn’t it?

glacial's avatar

@LostInParadise Most evolutionary biologists do not take group selection seriously. I’m so glad you’ve taken my point about not making this more complicated than it needs to be, in the interest of communicating the definition of the term fitness.

@janbb Yes and no. It is almost entirely about the passing on of genes – the implication is that individuals which are better adapted to their environment will pass on their genes. But to say that one is well adapted to one’s environment is meaningless unless it involves a heritable trait whose variation affects reproduction.

LostInParadise's avatar

@glacial , Saying that evolution is based on survival of the fittest is a tautology. Those genes that are best able to survive are those that are able to produce characteristics that allow them to survive. Nothing very profound there. It gets interesting when we talk about what the vehicle is for those genes, and I apologize if this means talking about things that go beyond the obvious. Genes do not walk around by themselves. Genes are contained in individuals and individuals are parts of families and members of populations. Group selection may not be favored by the majority of biologists, but it is at least a theoretical possibility. The mathematics was worked out by George Price. In theory, it is entirely possible that a gene for altruism could survive by promoting the survival of the local population group, even if that group is not closely related. Martin Nowak gives a nice mathematical framework for kin selection, group selection and 3 other evolutionary strategies that promote cooperation. For those who are put off by the math, just look at the diagram, which does a good job of describing the cooperative mechanisms.

Coloma's avatar

Well..I sure am pleased that my thoroughbred DNA trumped my daughters fathers Jackass DNA. Thank Gawd she got my quick brain and creativity over donkey dads deficits. lol

Dutchess_III's avatar

How did we ever let ourselves get impregnated by such idiots, @Coloma??!!

ragingloli's avatar

maybe you are overestimating yourselves

Dutchess_III's avatar

Or we underestimated ourselves then, Raggie.

Coloma's avatar

@Dutchess_III Touche…nothing like a racehorse being yoked to an ass. Major drag. lol

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