Evolution seems obvious to me. There are more breeds of dogs and cattle every year, not to mention flu strains.
But survival of the fittest seems wrong. If only the strong survive, then why are there enough weak born every year to feed the lions?
As Darwin himself worried in his books, how can you be sure it’s not just “survival of the survivors” ?
If each kind of animal is better suited than the last, how come we still have plenty of all those losers around. If coral are better suited than sponges, why didn’t all the sponges disappear?
It’s because you do not understand the meaning or concept “survival of the fittest”.
Because there is still a niche for the sponges. It’s a popular fallacy to say that only the strong survive. Instead, it’s more like the organisms best fitted to their environment survive. If the strongest/smartest/fastest animal always came out on top, there would be only one organism on Earth. Rather, organisms adapt themselves to their environment and evolution weeds out those ones which are most unsuited, which in many cases might be the larger or stronger ones. Sponges will survive until they lack an environment or are wiped out by predators, neither of which is likely to happen. And weaker individuals within a species will always be born; that’s the result of recessive genes and pure luck on the part of the parents to survive until they have offspring.
And selected breeding isn’t really evolution, or anyway, it’s artificial evolution. And the flu is not alive, though I guess it does follow some evolutionary patterns.
Isn’t part of evolution having more “variety” ? Mutations and variances allow for more changes that might be passed on… but that naturally entails “weak” individuals.
Also there are interesting arguments about the survival of the “group” or “collective” being in fact the purpose… the individual itself is disposable.
In the area in which coral is competing with sponges and is better suited than sponges, you get coral (usually). In some areas, sponges are better suited.
Also, a species which produces enough weak to keep a predator species fed will have their undesirables culled from the herd, and also not overpopulate, wipe out their food source, and starve. From this perspective, feeding the lions makes evolutionary sense.
Why are there losers in a poker game?
Your misunderstanding lies in thinking that there is only one goal. First of all there’s really no goal at all; life just happens. Natural Selection is just a way of trying to understand HOW life happens; your questions have more to do with WHY, which is outside of the purview of Science.
But there is not one goal. There is stuff for coral to eat, there is stuff for sponge to eat. There is stuff to be got the way that coral gets it, and there is stuff to be got the way that sponge gets it.
No organism has to have a reason to be; they only have to have a reason NOT to be. As long as an organism survives, it’s because there is food and a “niche” available to them. If food resources common to sponge and coral suddenly got really scarce, and there was only “room” in that niche for one of them, then one would out compete the other, and one of them would die out.
Evolution is not about winning. The key player in an evolutionary competition is the one who FORFEITS; the one left standing only “wins” be default.
As for your question about lions, how would lions survive if there weren’t weaker animals around to feed them? The SYSTEM survives, while some of its individuals die. But the “weaker” animals win too: if there weren’t lions around, the lack of evolutionary pressure would mean that, over many generations, they would probably have fewer offspring. With the predator in the picture, the one who has MORE offspring still has some left to pass along his genes, and some to keep the lion happy. So to answer your question, the reason there are still “losers” around is that they’re not losers. You seem to be equating “eating meat” to winning, but “eating grass” to losing. This is not logical.
I don’t think that you should consider “strong” as being powerful when speaking of the survival of species. Tigers are disappearing in the same region where insects flourish. Strong, survivalwise, comes in many varieties. Rats are strong in the survival sense because they reproduce so rapidly. Gazelles are strong because they are alert and wary and can run fast.
As others have said, the niche must be taken into account. When the environmental niche for a species disappears too rapidly for the species to adapt it goes extinct. At the same time in the same geographic area but not in the same environmental niche a smaller, weaker, slower, species survives.
To answer your title, Yes. Neo-Darwinism, AIUI is simply the best model/method to describe the evidence of evolution that we find. “Survival of the fittest” was not originally Darwin’s phrase, although he did adopt it in a later edition of Origin. The rest of your questions have been nicely answered already.
But isn’t that precisely the point? The weak that were born that fed the lions were the ones that didn’t survive, hence not the “fittest” (in a general averaged sort of meaning).
In order to survive, the gazelle doesn’t have to be faster than the lion, it only needs to be faster than the slowest of the other gazelles.
‘Survival of the fittest’ is a bit of a coarse term for a broad process, the effects of which can only really be seen statistically at population levels; if the effect of the lions is to eat the slower gazelles, and speed is a variable that can be passed on to offspring (even if not always), then the general trend amongst the gazelles will be an increase of speed over time; if the effect of generally faster gazelles is to tend to outrun the slower lions, and speed is a variable that can be passed to offspring, then the general trend amongst the lions will be an increase of speed in step with that of the gazelles.
As regards diversity, it isn’t a case of each being better than the last, but rather that there are all sorts of different resources to be exploited; when (through mutation) bacteria spontaneously acquired the ability to metabolise nylon as a food source, the other food sources that had been available remained available, so it was great for the nylon-eating bacteria; they got to run off in a new direction and take advantage of an untapped resource, but it was also great for the non-mutated strain because, well, it was business as usual.
Mangetout says it more clearly than my attempt.
But to reiterate and reemphasize:
“Survival of the fittest” does not mean there is one contest and one prize, and the it’s the survival of the lion versus the survival of the gazelle that’s at stake.
The term refers to the survival of the fittest gazelle. Of all the gazelles the lion has available to him, the fittest one is the one he’s least likely to kill. By killing off the weaker gazelles, the lion is actually doing the gazelle population a favor. He’s helping to ensure that the “fittest” gazelle is the one to pass on his genes, thus giving rise to fitter offspring. The lion killed the less fit gazelle, so that the less fit genes are less likely to pass on into the next generations.
So, within the gazelle population, and due to external evolutionary pressure in the form of the lion, the fittest gazelle genes have survived and reproduced. Voila, evolution driven by natural selection.
For a modern twist on a similar example, look at African elephants and their predators, ivory poachers. Ivory poachers don’t select their prey based on ease of captur–with the right gun, all elephants are pretty well equalized, fitness wise. They select their prey based on the size of their tusk. Thus, the elephants’ environment has changed to make large tusks = non-fitness to survive. In this topsyturvy world, the relatively rare condition of being born without tusks has become a strength, in that it helps the tuskless elephant survive longer than the big-tusked elephant, thus passing on more of his genes, thus making more tuskless elephants. This evolutionary pressure has manifested in a greater prevalence of tusklessness in more recent generations of African elephants. The poachers, then, have exerted a measurable evolutionary pressure on the elephant population. (But try to get an ID’er to listen to THAT bit of evidence.)
Two additions to the excellent comments already.
First, you should not “believe” in evolution (or neo-Darwinism.) The facts and evidence should convince you. The post actually is in line with this, but I think it is important to contrast acceptance of scientific theories with religious beliefs.
Second, the “fitness” in survival of the fittest is reproducing, not living a long time. Salmon die right after they spawn, for instance. Think of the cases where a male insect dies right after sex. It’s a subtle point, but important in understanding why some species evolved the behaviors they did.
You don’t even have to be all that strong to survive; just reasonably lucky. Only in very harsh environments is “strength” (which generically covers speed, camouflage, the ability to go longer without food or water, venom, resistance to venom etc.) critical. In lusher, more relaxed settings, even the schmoes of the animal world can get by.
Certainly on an individual basis, luck is a large factor in survival and reproduction, however at population scale, these odds are generally expressed in such a way that even minor advantages prevail in the gene pool and similarly minor disadvantages are deselected.
True, but at any given moment there will plenty of lifeforms around that make us scratch our heads and ask “How did a loser like him get a date?”
That’s true and in fact is one of the reasons people sometimes find it hard to grasp or accept evolution; you can’t see it happening unless you stand waaaay back, but when you do that, you can easily lose sight of how it is happening.
Another problem is that we are not particularly good at judgning what represents a successful survival strategy; my boss (who is genuinely not a creationist, but says he doesn’t accept evolution :dubious: ) keeps saying things like “Look at the giraffe! How could ‘survival of the fittest’ produce something as clearly unfit for survival as the giraffe?”
Last time he said this, I pointed out that if giraffes truly were unfit for survival, we wouldn’t be discussing the matter, because there simply wouldn’t be any giraffes alive for us to look at.
And I just wanted to add that there is no belief system called “Darwinism”.
This is the fundamental flaw in eugenics. We simply don’t know what combination of traits makes for survival in any environmental niche or niches. We can selectively breed animals for a particular characteristic, like speed for a mile and a half in thoroughbred race horses. However lots of those horses have so many physical problems that the owner almost needs a verteranarian on retainer.
What the OP addressed, but this thread so far does not seem to, is the question, “What is the difference between Darwinism and Evolution (if any)?”
Google’s collection of definitions would seem to indicate that they are essentially the same.
If they are the same, the answer to the OP (Can a person believe in evolution but not Darwinism?) is “No.”
(Note that Darwinism alone is not a single theory.)
As the old joke goes, it was because he was off in the corner licking his eyebrows. 