A while back (a long while, by now), a friend-of-a-friend mentioned something interesting....

[conuly]

She said that most people she knows who accept the Theory of Evolution ignore "large holes" in it. Now, that may be, and those holes may exist. However, in my experience, most "large holes" mentioned are not, actually, large holes at all - or rather, they're holes in the knowledge of the questioner.

I'm hardly a biologist. However, if you post any complaints you have with evolutionary theory, with one exception... no, two exceptions, I'll gladly start running around to see if I can find answers. Or maybe one of my other friends can answer the problem.

The two exceptions are as follows:

1. I'm not answering that damn chicken or egg question, or any transparent version of it.
2. I'm not answering any question that has to do with the creation of the universe, or the beginning of life. If you say "See, this means there must be a designer", I'll quietly sigh, because the only response to that is "Well, who designed the designer", and before you know it we're having the second-silliest flamefest in history. There might very well have been some sort of original creator(s) or designer(s). I don't know, I don't care, that's onen puzzle we're never getting to the bottom of.

Comments

[literalgirl.livejournal.com]

Well said.

And I don't actually have any questions, but I am glad you are there if I think of any! :-)

[conuly]

The best part of this is that if I can't find an answer, or don't know the answer myself, I can't "disprove" anything, since I admit upfront that I'm not an expert.

The Big Questions

[pockingell.livejournal.com]

Well, you asked for it:

I just realised, I don't really know what the Theory of Evolution is, apart from vaguely understanding that it's along the lines of "small changes occur between individuals, and the changes which allow the individual to survive longer are passed down". What is the actual theory?

Re: The Big Questions

[conuly]

I'm pretty sure that *is* the theory. Hard to see what else could be involved in it. Evolution just means changes through time, and it occurs through the process of natural selection. And pure dumb luck - if a volcano wipes out all the people who carry X gene, that gene is gone from the population, even though that has nothing to do with the survival value of those people, or that gene.

[atdelphi.livejournal.com]

Ooh, I've got one - not really about a 'hole' in the theory, but rather about making the argument for the theory itself (keeping in mind that I'm the least scientific person in the world.)

Now, I know the reason it's referred to as a theory is because macroevolution, due to the obvious time spans involved, hasn't been directly observed. Rather like the way that our 'knowledge' of the earth revolving around the sun was only a theory until we actually sent satellites out to snap pictures.

My question is: are there any other pieces of scientific knowledge that the general public takes for granted that are really only 'theories'? I could definitely use an example to trump those who smugly play the "Why do they call it a theory, then?' card.

[literalgirl.livejournal.com]

But a very smart non-expert. :-)

Re: The Big Questions

[leora.livejournal.com]

That's almost it, except it's not really survive more so much as be present more. Longer lifespan means you need to reproduce less to have more of them around, since they stick around. But you can also take the reproduce a lot path. Things that help you make more of you be around will be around more.

It's pretty incredibly obvious, which is why it's ridiculous to argue it. But most people only argue with some of the higher level conclusions.

It's often nicknamed survival of the fittest or survival of the sexiest. Fitness is whatever makes you able to have more of you, which is why it includes counterintuitive things like a peacock's tail that makes it easier for predators to catch it, but gets it babes. And it includes sacrificing your own life to protect your children, at least in certain cases.

And, as Conuly said, luck plays into it. Sometimes something is more beneficial, but it's not very present yet and everything with it happens to get killed in an earthquake. But generally, more helpful traits will become more prevalent. And while there are many random mutations and most are harmful, some will be helpful, and those have a better chance of propogating.

[rho]

Atomic theory would be a good one. Or quantum theory. Or the theory of relativity. Slightly more esoteric, we have things like game theory. Or if we allow a little bit of linguistic leeway, how about pythagoras' theorem, which is occasionallyr refered to as pythagoras' theory?

The "it's just a theory" brigade annoy me immensely because they completely ignore the way that the word is used scientifically. In a scientific context, it can mean a framework and system for understanding things just as much, if not more, than it can mean a hypothesis or conjecture.

[conuly]

Gravity.

[conuly]

I mean, we call it a law, but a law is just a trumped up theory with a fancier name.

Rho's answer is better :)

[leora.livejournal.com]

All accepted scientific knowledge is a theory. That the Earth revolves around the sun is a theory. A theory that Einstein, in fact, gave us reason to question with his theory of relativity. Now we know it may be more accurately described as saying from one point of view, the Earth revolves around the sun, but other points of view are equally valid but generally less useful.

The only difference between theories is how much support/evidence we have for them. There is no absolute knowledge in real science. Everything can be theoretically disproven. And our long-held ideas about Newtonian physics were shown to be incomplete. They're a good model, but not a perfect model. Pretty much everything is assumed to be an imperfect model, but we use the best ones we can create and improve them as we go. That's what science is.

Faith is the only thing that tries to claim absolute truths. And it can do so because it has absolutely no requirement to have any evidence to support it whatsoever, and generally is able to throw away any evidence that conflicts as irrelevant. That is why faith makes claims of absolute knowledge and science does not.

[leora.livejournal.com]

The usual retort I hear to, "it's just a theory" is, I have a theory that if I punch you in the head, it will hurt. But that's just a theory.

Tongue firmly in cheek

[pockingell.livejournal.com]

Thought so. Okay, new question. You refer to the "second-silliest flamefest in history". What's the silliest? And the third-silliest? Is there a top ten of silly flamewars out there?

Re: Tongue firmly in cheek

[conuly]

The silliest is one somebody told me about, where people got into an apparently serious argument over the statement "the sky is purple". She kidded me not.

Third place is a tie between "how many angels can dance on the head of a pin?" and "did Adam and Eve have belly buttons?" These flamefests are ongoing in scattered areas around the world.

Re: The Big Questions

[rho]

In addition to what conuly and leora have said:

There are actually two big processes going on which are related but very different. One is the changes within a species. Your proto-giraffes are having a hard time, so the ones with slightly longer necks mange to reach more food, so they're more likely to survive, so the genes for having long necks get passed on to their offspring. This is what Leora and Conuly both describe.

Then there's the creation of new species. What actually happens there is that you have one starting species, which then diverges into two, which aren't capable of breeding with each other. This generally happens when there are two separate populations that don't breed, for one reason or another, and then the two populations change sufficiently with respect to each other that it would no longer be possible for them to breed.

The separation can be for any of a number of reasons: a mountain range gets put up in the way, one lot live at the lake bottom and the other at the shore, one lot has females attracted to red mates and the other has females attracted to blue mates, and so on. And equally, the changes between the two populations could be due to a "survival fo the fittest" type effect, or they could just be down to random geetic drift.

So for instance, if we go back to our proto-giraffes, while there was one group staying out on the plains and getting taller, another group retreated into the forests and lived there, and eventually evolved into the okapi.

It's these two effects working in parallel which have led to the great diversity of life on earth today.

Re: The Big Questions

[conuly]

This generally happens when there are two separate populations that don't breed, for one reason or another, and then the two populations change sufficiently with respect to each other that it would no longer be possible for them to breed.

I have a question about that. Is it right for me to say that chihuahuas and Irish wolfhounds aren't the same species, because they can't interbreed? Kind of like how there are a number of mutually intelligible dialects between Dutch and German (yet Dutch and German are not, at the far end of that spectrum, the same language), there are many mutually...reproductive breeds between chihuahuas and Irish wolfhounds. Does that make sense?

Re: The Big Questions

[rho]

What you're saying does make sense, yes. I'm not a biologist either, so I can't give you a definitive answer, but I can give an answer based on my understanding.

The "cannot interbreed" thing is generally no longer accepted as the defining characteristic of a species. It's a convenient fiction, and it works in the vast majority of cases, but there are cases where it just doesn't hold up, and if you try to hold to itunwaveringly then you end up with some very counter-intuitive results.

It's sort of like mutual-inteligibility in languages. Danish and Norwegian are considered different languages, whereas Mandarin and Cantonese are considered to be dialects of Chinese.

At the end of the day, the definition of a species is somewhat tautological: something is a species because we say it's a species, because it looks like a species. And under this definition, all breeds of dog are considered to be members of the same species (and I believe that current classifications put them in the same species as both the wolf and the dingo as well).

[rantinan.livejournal.com]

Huzzah for explaining scientific language!
Point of order tho. Hypothisis is the basic premise. Theory is what you come up with after you consult the evidence.

it's one thing that is 100% garunteed to get my goat is saying evolution is proved.
Its up to people who understand scientific terminology to attempt to educate morons, and not to devolve to playing semantic games with the fools.

I propose the following example for utilisation aginst morons.

" If we had a scientific proof that resulted in a law of evolution I'd utilise it to devise a methodology of forcing stupidity and religious tendencies the fuck out of humanity. It's a good theory, it's a correct theory, it's a theory with unarguable scientific evidence. The reason it remains a theory, not a law, is because it's not been fully proven in an experimental setting.
If it was to be proven in experimental settings, it would be a law. Here is a proof for netwtons law of motion. Every reaction (like my fist impacting your face) has an equal and oposite reaction (having to brace myself aginst the force of your skull gaining a backward vector, which when assisted with gravity will end up with you lying ass downanrds on the floor) It is easly and systematicaly proven, we can conduct an experiment arround it (if I punch your mornic fundimentalist ass hard enough 10 times out of 10 you will go down, and I will have sore calves. If in an environment where the effects of gravity are minimal, I will fly backwards into the bulkhead instead of getting sore calves.) "

Ironicaly enough, most of the biologists, botanaists et al I've spoken to in person have been religeous. Doesent stop them from also agreeing that the theory of evolution is rock solid.

Re: The Big Questions

[ahsirakh.livejournal.com]

Actually, there are many possible parts in the theory which you can believe in (behold: the Wikipedia article! (http://en.wikipedia.org/wiki/Evolution)), which is why saying one believes in the existence of evolution is vague, and one trying to slam evolutionary theory tends not to succeed because they usually only attack a single prong of all evolutionary theory, which comprises numerous prongs of theory.

Re: the chicken and the egg, I think it's a cute question which is pretty much agreed on if microevolutionary theory, even by natural selection alone, is to be believed: the egg came first. The original chicken and the egg paradox relied on the assumption that chickens can only be hatched from eggs laid by other chickens, but chickens could very well have evolved from "other species" (the quotation marks are based on how you treat the human divide of species). This means that the chicken oculd have come into conception with the right mix of genetic traits in an egg from chicken-like species resulting in a chicken as we know it.

Re: The Big Questions

[ladytalon.livejournal.com]

I like to think that the "cannot interbreed" part of the definition of species was thrown out partly due to paleontologists and evolutionary biologists talking to each other, where paleo-types got a chance to say, "Um, our things are dead, we don't know if they could interbreed. Wups!"

I'm not an expert (that phrase gets a lot of use here) on dog breeds, but I think they're considered subspecies? Meaning they have clear differences, but they're still the same species. If you take a Great Dane ovum and fertilize it with a Chihuahua sperm and implant it in some willing mother dog, you'd get a viable offspring.. at least I think so. And if it's not sterile, then they're still the same species. Um, I have no idea if anyone ever bothered trying, though.

As an aside, though, Rho, I've never heard of the wolf and dog being the same species; is this very new? Or not very widespread yet, maybe?

Re: The Big Questions

[rho]

That may be part of the reason why the interbreeding restriction was lifted, but I don't think it was the only reason. Take, for instance, the fire bellied toads. There are two species of fire bellied toads that live in Europe: one in the east and one in the west. For all intents and purposes, you'd consider these to different species. They look different, they have different behaviours, they're genetically distinct, and so on and so forth. Yet in a very narrow boundary, where the territories of the two species meet, they interbreed quite happily. IIRC, there's practically zero gene flow out of this area, so both species remain genetically "pure" except for in this one tight zone.

Another reason, I believe, is to try to be more general across different kingdoms, rather than the animal-centric definition. it's perfectly common for plant hybrids to be viable, and that doesn't mean that they should be considered the same species.

With regards to dogs and wolves, wikipedia says:

Dog, in common usage, refers to the domestic dog, Canis lupus familiaris (originally classified as Canis familiaris by Linnaeus in 1758, but reclassified as a subspecies of the wolf, Canis lupus, by the Smithsonian Institution and the American Society of Mammalogists in 1993).

I'm not at all sure as to why they were reclassified this way, but from reading the rest of that wikipedia article, I do have a suspicion. I'd guess that because different breeds of dog were evolved from different subspecies of wolf, that would mean that they were genetically closer to some wolves than to some other dogs. And especially with the rise of cladistics amongst taxonomists, that sort of thing doesn't really make for a good species.

[theshiversbaby.livejournal.com]

If the T. of E. is correct, there must be an incredible number of stages in development for each species as the species slowly evolved. For example, there should have existed all of the steps between some early form of, oh I don't know, elephant that we'll call "Proto Elephant," and the elephant as we know it today, "Modern Elephant" (yes, I realize there is more than one kind of elephant, I'm just oversimplifying for the purpose of clarification). Assuming that Proto Elephant is quite different from Modern Elephant, this process must have taken quite a long time and a large number of developmental stages.
Two questions: a) Do you think this is correct?
and b) If so, why haven't we found more skeletons supporting this fact? I'm mean, obviously we've found skeletons of things we classify as separate species - in the case of humans, for example, we've found Homo habilis, Homo erectus, etc. But we don't seem to have found many skeletons between these stages. They all seem to belong to distinct species. Why? Does this mean that every stage of development, no matter how miniscule, could be classified as a different species? If so, we should be a few thousand species beyond Homo sapiens, then.

[theshiversbaby.livejournal.com]

[Edit: I guess we're really Homo sapiens sapiens. Right? And I may have messed up some capitalization. I'm not a biologist in the least.]

[conuly]

1. Yes
2. Skeletons don't last as long as we might think. If they did, we'd be standing knee-deep in dead bodies all the time. Also, classifying them is a pain in the insert body part. Look at the fuss made over the new "hobbit" skeletons found a few months ago! Are they a "new" species? Or just part of this species? We don't know. Were Neanderthals, in fact, a different species, or did they mate with our own ancestors, and add their genes to the population? We don't know.
3. Does this mean that every stage of development, no matter how miniscule, could be classified as a different species?

The standard definition has to do with the ability to produce viable offspring. Since we can't determine that from fossils, we can go to an alternate definition, which has to do with genetic similarity. Except we can't, because we don't know how similar we have to be to be the same species, and I'm fairly ...

Sorry, I'll type up a better (and complete) reply after feeding the kid.

[conuly]

...fairly certain that you can't extract much DNA from fossils anyway. That's what makes them fossils. So, really, when people talk about extinct species, they're making guesswork. They don't know where one species belonged or another did.

Think of a clock - one with only four numbers, 12, 3, 6, 9. You know that one revolution of a second hand is a minute, one revolution of a minute hand is an hour. Let's say that we are at the 12 spot, and some ancestral species is at the 3 spot. We measure time with the minute hand. At what point in the evolutionary cycle does it stop being the ancestral species and start being some "intermediate" species?