Is evolution still a controversial theory?

Mr Gone:

So, you have these tendirls of dark energy that clusters of galaxies "travel" on....its mind blowing to think about.

That it is, sir. I'm going to be pondering that for a while.

I tell you, there's nothing like astrophysics to give you a sense of wonder and wide-open possibilities. Hard to imagine there were ever those misguided Romantics who saw science as somehow adverse to creativity and imagination. This stuff gives your mind a good stretch.

Black Flag:

Mr Gone:

So, you have these tendirls of dark energy that clusters of galaxies "travel" on....its mind blowing to think about.

That it is, sir. I'm going to be pondering that for a while.

I tell you, there's nothing like astrophysics to give you a sense of wonder and wide-open possibilities. Hard to imagine there were ever those misguided Romantics who saw science as somehow adverse to creativity and imagination. This stuff gives your mind a good stretch.

It does indeed. Blows my mind often...

The problem with that poll, I think, was the lack of good choices.  Do you believe in evolution?  Yes/no/don't care.  What about refining what sort of evolution?  Of course evolution occurs within a species.  Its even observable in some species within human lifetimes.  The real question is whether or not cross-species evolution is real.

I'm not going to say I can prove either way, I absolutely can't, but, well, nobody can.  Maybe in a few hundred years, it'll be proven Galileo style (quick history lesson: his proofs really were wrong, so you can't blame people for disagreeing just because he took a lucky guess), but for now, I just think more needs to be done to convince me.

Creationists are not the only ones who question cross-species evolution, and frankly, I think they give the other side of the issue a bad name.  There are religious intellectuals as well, who grapple with other questions, such as ensoulment.  Or my biggest problem with the idea...if A and B are fundamentally different things, but A evolved into B, there was a moment in time when Generation N was A and Generation N+1 was B, and I just see no evidence to suggest that's possible.

And besides all that, I was pretty sure that ultimately, Darwinian style evolution was disproven years ago.  Something about the time frame during which evolution occurs.  I don't remember, really, since its not exactly a topic I sit up at night thinking about.

What do you mean by "cross-species evolution"?  That term doesn't mean anything to me.  I Googled it and got no pertinent results.

Darksider:

What do you mean by "cross-species evolution"?  That term doesn't mean anything to me.  I Googled it and got no pertinent results.

I don't know what the proper name is, that's just what I've always called it.  Anyway, I mean the idea that one species can become another different species.  The iconic one, of course, is some non-human species turning into humans, but it works for me regardless of what specific ones we're talking about.  The notion that a generation of species A could give birth to a generation of species B seems ridiculous.  In general, when I talk about this problem, all I get is backpedaling on the definition of "species."

In other words, specifically (though put simply), I have no doubt that the human species evolved over time, but I remain convinced that along all steps of that evolution, this particular creature still remained a human.  At no point in its evolutionary history was this creature ever not a human.

So, ultimately, if someone talking about Darwin's birthday asked me if I believed in evolution, I would have to do quite a bit of qualifying, and would probably pick "don't know" if I could only pick yes/no/don't know.

i think he either means when 2 species breed so Species A + Species B = Species AB

OR

he means something like this

and either way go back far enough and we were all fish with similar makeups.

Edit: there's also an interesting article on parallel evolved traits in 2 different species here

mplindustries:

Anyway, I mean the idea that one species can become another different species.

I believe you mean speciation, which is the process in evolution where one species is split into multiple species (though usually just two).  Phrasing it as one species simply becoming a new species is a bit misleading, because the general process is more complicated.  Speciation is a primary part of evolution.  Just believing in the genetic change within a single species over time isn't believing in the modern theory evolution.

Also, a note, Darwin's specifics were 'disproven' in a sense.  But really, the modern theory of evolution is Darwinian, it is simply more refined and detailed thanks to all the knowledge we have now that he did not.

mplindustries:

The notion that a generation of species A could give birth to a generation of species B seems ridiculous.  In general, when I talk about this problem, all I get is backpedaling on the definition of "species."

There is a problem in the sense that the biology community has multiple definitions of a species and there are constant arguments about which is the best to use for any given situation.  The process of delineating between two distinct species as the emerge is not standardized.  We haven't formalized a way to 100% say that one situation is simply two populations of the same species, and another situation is two populations each of a different species.

But why is the idea that one species gives rise to a new one ridiculous?  All of the biological mechanisms needed for it are clearly observable in the world.

mplindustries:

At no point in its evolutionary history was this creature ever not a human.

Then were did the first human come from?  At one point there were no terrestrial creatures.

I think there's a misunderstanding about how evolution and speciation really works. It's not cut and dry because biology and genetics don't work in terms of binary switches. Yes, we know that birds can't breed with canines or that cats can't breed with dogs, but those situations arise from historical, long-standing species. There are a lot of interesting gray areas.

For instance, I'm still looking for a citation, but I remember a biology teacher I had recently explained speciaition using North American frogs of some variety. Turns out there's a kind of frog that lives all along the eastern half of the US and even further south. Frogs in each region are slightly genetically different from one another, but they are still basically the same frog. Frogs from region A can breed with region B, frogs from region B can breed with frogs from region C, and so forth. But what's interesting is that frogs from region, let's say, region H cannot breed with region A or B, but they can breed with everything south of there (more or less). Eventually frogs in region A and region H will be distinctly different species from one another, but the other frogs in between will not clearly belong to either species. This is because while mutation is spontaneous, speciation is not.

Humans,  presumably, went through a similar process. This is why a number of human-like creatures shared Africa at around the same time and may have even warred with one another, though not all theories agree with how many of them were truly difference species and how many of them just looked different.

Zeev:

Then were did the first human come from?  At one point there were no terrestrial creatures.

There was also a time when there was no life at all.  Where did that come from?  I would say the same place, though I couldn't say what that place was.

I always found it interesting that there are holes in every single fossil record. That missing link thing is not unique to humans.  However, instead of thinking, "well this is across the board, so maybe these things are not all linked in nice little packages like we want," people just assume they know and they make up all kinds of crazy things and jump to conclusions.  I think, all too often, science tries to make claims beyond its capabilities.  The fact is, we don't know any of this stuff is true.  Its not actually proven.  I think there is nothing wrong with just saying the truth: "We don't know the answer.  We can guess, but at this moment in history, we lack the understanding/technology/what-have-you to really prove anything.  Give it some time."

mplindustries:

I always found it interesting that there are holes in every single fossil record. That missing link thing is not unique to humans.  However, instead of thinking, "well this is across the board, so maybe these things are not all linked in nice little packages like we want," people just assume they know and they make up all kinds of crazy things and jump to conclusions.  I think, all too often, science tries to make claims beyond its capabilities.  The fact is, we don't know any of this stuff is true.  Its not actually proven.  I think there is nothing wrong with just saying the truth: "We don't know the answer.  We can guess, but at this moment in history, we lack the understanding/technology/what-have-you to really prove anything.  Give it some time."

What is your definition of "proof"?

No science deals in absolutes. We cannot absolutely prove anything outside of mathematics; everything is based on logical inference. There will always be a hole in the fossil record. Science doesn't "jump to conclusions"; it's actually an extremely painstaking process by which every theory comes under constant assault be detractors and reviewers.

Science says, "Look, there's a body of evidence here. It's massive. It's impossible to ignore. There's no smoking gun, because smoking guns are rare almost to the point of non-existence in science, but we deal in data. All the data we have supports this theory, and that's all we're saying. No more, and no less." Science doesn't really claim to know anything. It presents the evidence it has and weighs them for or against theories that incorporate them. Because, really, from a fossil perspective, we'll never "know" anything in the sense that detractors seem to want. But if I can produce an extensive fossil record that shows a number of slight variations between species, which becomes more human-like over time, that's data. That's significant. Everyone is free to ignore that data, of which there is an absolutely massive volume, and wait for the "smoking gun" to emerge, but it never will. There will always be smaller and smaller holes in the record because we cannot possibly find every bone that ever was, if indeed every bone was fossilized at all. "I refuse to believe this until you can show me an alien hologram depicting the step by step evolution of man" is demanding an awful lot of science. "I don't have to believe this because you cannot dispel all doubt" is skeptical to the point of insanity. Especially since it tends to be religious people who espouse it.

Mendrian:

There are a lot of interesting gray areas.

Too the point where really, the gray areas are the 'rule' and the cut-and-dry species of animals are more the exception.  Plants seem to love to take whatever definitions of a species that biologists come up with and then promptly ignore it.

Mendrian:

For instance, I'm still looking for a citation, but I remember a biology teacher I had recently explained speciaition using North American frogs of some variety.

There's plenty of cases like this.  Another example are some of the gulls of the Northern hemisphere.  If you start in Asia, you can track different populations of highly related gulls moving in either direction.  When both directions have gone around and met on the other side of the planet (in the NE USA) you end up with two distinctly different gulls.

mplindustries:

There was also a time when there was no life at all.  Where did that come from?  I would say the same place, though I couldn't say what that place was.

This doesn't really hold.  While we can't solidly pin down the origin of life, how life works once it exists is something we can pin down.

mplindustries:

I always found it interesting that there are holes in every single fossil record.

Why?   The fossil record is simply finding the bits and scraps of what's left.  Nature wasn't sitting around saving it for us to find.  It wasn't 'meant' to be a record.  The idea that it has holes seems fairly natural.

But you seem to be making the mistake that having the truth is a binary state: either we are 100% sure or 0% sure.  But that's not how science actually works.  Science actually measures how sure it is on a scale.  Being 99.9% sure is good enough for science, and it is far more than just winging it.

Zeev:

Science actually measures how sure it is on a scale.  Being 99.9% sure is good enough for science, and it is far more than just winging it.

Hooray for Bayes!

mplindustries:

Or my biggest problem with the idea...if A and B are fundamentally different things, but A evolved into B, there was a moment in time when Generation N was A and Generation N+1 was B, and I just see no evidence to suggest that's possible.

Because that doesn't happen. Fortunately, that doesn't stop speciation from happening.

OK. Let's abstract to explain how it actually is by the magic of analogy. Say you have... a big matrix of numbers, ten by ten on a side. Each generation, you get to change two numbers.

Two matrices are 'compatible' if they share at least twenty numbers. Crucially, while one matrix may be 'compatible' with

Replace matrix with genetic code, and compatible with reproductively compatible, and voila, speciation by analogy.

The fundamental error lies in thinking that you can draw a ring around a group and declare it a species, and that each member may mate with all other members and no non-members. In fact, if you take two compatible specimens, each one will be capable of mating with most members of the other's group and few of the specimens not members of the other's group. Kinship is a matter of degree, not a matter of kind. For all my waffle, that's what I've really been trying to get across: kinship is not a matter of kind. There is no well-defined group you can plonk a set of creatures past and present in and say "Dog." It wasn't a matter of a "Wolf" whelped a "Dog". A wolf whelped a slightly doggier specimen whelped a slightly doggier specimen still...

Although I'm sure it won't satisfy you as it only shows the initial stage of speciation (that of isolation) and you could, technically, artificially impregnate one strain with another, fruit flies have been repeatedly reproductively isolated.

Mendrian:

We cannot absolutely prove anything outside of mathematics;

Theoretical algebra. ;)