Poll: Do you believe in speciation?

[Ancientgamer]

I find it laughable that anyone actually seriously believes in macroevolution. No, I don't care if you have 5 billion years, I don't care if you have 100 billion years, the odds are so astronomically small that I don't think most people even comprehend what they're saying. (Not to mention we have absolutely no evidence that the earth of had the right conditions to form life 5 billion years ago.)

In no other situation would speculation like that be taken seriously, you'd be laughed right out of your job.

Thing is, in darwin's time, human cells were just seen as big homogenus blobs. That seemed a lot more plausible. But the knowledge we have now of micro biology completely debunks darwins theory. I'm sorry, but you believers must have an awful lot of faith to believe in something so utterly ridiculous. Pastaferianism looks completely respectable next to "umm..it just like...happened LOL"

 

[Alex_P]

Wouldn't a flightless wing be more of a disadvantage and more or less just get in the way? Isn't that just a weakness?

Sometimes certain dire circumstances just don't come up for, say, millions of years. [http://scienceblogs.com/notrocketscience/2009/04/retrocyclins_a_defence_against_hiv_reawakened_after_7_millio.php]

-- Alex

 

[Bruiser80]

Wouldn't a flightless wing be more of a disadvantage and more or less just get in the way? Isn't that just a weakness?

Not necessarily, and it could be paired off with a beneficial mutation.

So, for every evolutionary step improving a vesital limb (a wing), there would have to be an overpowering beneficial mutation (lighter frame, leaner bone structure). And this would have to continue on and on and on until finally you have an animal fit for flight.

I think this is where some skepticism is due. The odds are definitely stacked against the flightless bird. Over time, the statistical improbability is overcome, and you have a new species.

It's definitely the best guess we have, and I stand by teaching it to children, but the weaknesses of the theory should also be addressed. It's the best we got, but we don't want children to get discouraged in someday improving the theory.

 

[sneakypenguin]

I'm skeptical, to me the argument seems to be based on the magical ingredient"time" .
All the theories have such massive holes in them I find it irresponsible to just accept it as "fact"

 

[Internet Kraken]

The reason you don't understand how speciation could work is due to your own lack of knowledge.

For example you say that if a new species is born it should die off because it has no one to mate with. This assumes that one species suddenly gave birth to a completely different species. This is not the case. New species are the result of gradual changes over massive periods of time. These changes occur gradually, so there is not a reproductive barrier set up between this individual and the rest of the species because there are not enough genetic differences between it and the rest of the population for it to qualify as a new species. Over time these differences will increase and eventually reproductive barriers will form. However, by this point there will be many other individuals within the new species, so reproduction can still occur.

Yes, I do lack a great amount of knowledge on this topic. But how is it exactly that a reproductive barrier suddenly pops up between two species?

I'm not sure how a post-zygotic barrier comes to be. I believe that the gradual changes eventually modify the reproductive organs of the species to the point that they are no longer compatible.

However I do know that sexual barriers can be pre-zygotic. These occur due to changes in a populations environment or behavior. For example, there could be a species of flies that mate on a red flower. Some of the flies can't find a red flower to mate on, so they mate on a white flower. Eventually more members of the fly population mate on the white flowers while the other mate on the red flowers. Eventually sexual reproduction between the two species ends because they are separated by the environments in which they mate. This would be an example of the pre-zygotic reproductive barrier of habitat isolation.

Again, those species could still get back together at some point, maybe even by accident, and mate, still making them the same species. I don't understand how a species can mutate so much that it becomes incompatible with it's own species, and yet still compatible with another.
I'd also like to say that i may be making myself to look like a complete idiot, which I quite frankly am in this field. But i think that we will never know where we nor the earth came from, and it's okay to have theories but when something that can't be proven is more or less forced to be true, it really bothers me.

In terms of pre-zygotic barriers, a species usually can still mate and produce a fertile offspring. However, isolation by, for example habitat, make the mating between two species difficult. Eventually over time the genetic differences accumulated over the years of separate breeding make the reproductive organs of the two species incompatible.

This is all in your biology textbook. Look up pre-zygotic and poss-zygoitc reproductive barriers.

 

[dnnydllr]

So if it takes a hundred million years for new species to form and there are probably a hundred million species on the planet...well that's a rather large number isn't it? I see speciation as something that would take beyond infinity to occur.

It doesn't take that long. Ever heard about goats and sheep? They used to be the same species until humans started breeding them for huge fleece or higher milk production.

Actually, according to this, they are quite distant relatives.
http://en.wikipedia.org/wiki/Sheep-goat_hybrid

 

[Thunderhorse31]

To be clear, we're discussing speciation right? Not local adaptation, not differentiation of population (which MAY lead to speciation, but there's no way to assume in advance, and to date it has not been observed outside of plant life), but the actual splitting of one species into two distinct ones, yes?

Yes, and there's evidence of it in human history. Dogs and wolves for instance.

Do you mind providing me with a link or something that shows that (I really do want to look it up)

So if it takes a hundred million years for new species to form and there are probably a hundred million species on the planet...well that's a rather large number isn't it? I see speciation as something that would take beyond infinity to occur.

It doesn't take that long. Ever heard about goats and sheep? They used to be the same species until humans started breeding them for huge fleece or higher milk production.

If we're talking about evolution (specifically Darwinian evolution) than the topic is undirected, unguided change, so this example doesn't exactly apply. Would sheep and goats have become incipient species' had humans not directed their adaptation?

 

[insanelich]

I'm skeptical, to me the argument seems to be based on the magical ingredient"time" .
All the theories have such massive holes in them I find it irresponsible to just accept it as "fact"

It's not a "magical" ingredient, it's an essential ingredient in amounts most humans find it an incomprehensible concept.

It happens a lot with very large concepts - doubly so with infinity. Untrained/inept people cannot face the scale required and instead block it out.

Mutation + selection + time = evolution. Simple and unavoidable.

 

[Internet Kraken]

I'm not sure how a post-zygotic barrier comes to be. I believe that the gradual changes eventually modify the reproductive organs of the species to the point that they are no longer compatible.

However I do know that sexual barriers can be pre-zygotic. These occur due to changes in a populations environment or behavior. For example, there could be a species of flies that mate on a red flower. Some of the flies can't find a red flower to mate on, so they mate on a white flower. Eventually more members of the fly population mate on the white flowers while the other mate on the red flowers. Eventually sexual reproduction between the two species ends because they are separated by the environments in which they mate. This would be an example of the pre-zygotic reproductive barrier of habitat isolation.

How exactly would this be speciation/cause the two groups to be incompatible?

I'm pretty sure that even though I've had zero contact with the Aborigines, I'd be able to mate with them

Well you just described how it can work. Even though you could produce a viable offspring with them, you have had zero contact with them. You are separated by your habitat. That is a pre-zygotic barrier.

If two species are isolated from one another over massive periods of time then post-zygotic barriers can form. These are formed once the genetic differences between the two species are so vast that their reproductive systems are no longer compatible.

 

[Kpt._Rob]

If you really want to see how evolution is not just a viable theory, but in all probability is the best solution for why we have different species, you should read Dawkins on the issue. I'm not saying you have to read "The God Delusion" (although it is an excelent book), but if you want to get the argument for evolution, without the conversation about religion, read one of his earlier books, "Mount Improbable" for instance. Dawkins is a man who really understands evolution, he's excited to speak about it, interesting to read, and really quite eloquent.

 

[Bruiser80]

Also I'm all for healthy skepticism of the divine mandate of Science!, but there's also the thing called doubting too much. We have plenty of data that supports evolution, unlike, say, string theory or big bang. Data that should be considered rather than outright dismissing it in a fashion very reminiscent of "it's not in the book, it never happened".

And I think creationists and skeptics are treated by pro-evolutionists as "it's in the {science} book, it must have happened"

 

[Dando Dangerslice]

Here's an interesting bit of info:

The herring gull and the lesser black-backed gull are two species of birds that live around the Arctic Circle. They mingle frequently around the UK and even live together in colonies, but they don't interbreed.

Now, if you trace populations of the herring gull westward to Canada, across the Bering Strait, they get less like herring gulls as they go along and more like black-backed gulls, if you carry on across Russia and northern Europe and back to the UK you find that both the black-backed gulls and the herring gulls are at either 'end' of a continuous chain. Any population of birds close to each other can breed (like the gulls in western Canada being able to breed with the birds of eastern Siberia) but the 'pure' herring gulls and the 'pure' black-backed gulls never do interbreed.

This is true, it's a phenomenon that exists on Earth right now.

 

[Internet Kraken]

I'm skeptical, to me the argument seems to be based on the magical ingredient"time" .
All the theories have such massive holes in them I find it irresponsible to just accept it as "fact"

A theory in science is different from the standard idea of a theory.

In science, a theory is a hypothesis that has large amounts of evidence to support it and little evidence that works against it. The theory of evolution has large amounts of supporting evidence and little evidence working against it.

Also it's not time that causes evolution. It's the slight genetic differences from one generation and another. It's just that you only notice these genetic differences when you compare a species to it's ancient relatives. Then you can see how over time these gradual genetic variations eventually led to massive changes.

 

[Dando Dangerslice]

If you really want to see how evolution is not just a viable theory, but in all probability is the best solution for why we have different species, you should read Dawkins on the issue. I'm not saying you have to read "The God Delusion" (although it is an excelent book), but if you want to get the argument for evolution, without the conversation about religion, read one of his earlier books, "Mount Improbable" for instance. Dawkins is a man who really understands evolution, he's excited to speak about it, interesting to read, and really quite eloquent.

My above post was into from a Dawkins book: The Ancestor's Tale. Fascinating read, even if he does mis-quote my hero, H.G. Wells, and call him a racist

 

[Ridonculous_Ninja]

Well it is possible that they are wrong, but until proven wrong it is perfectly safe to go with the current theory. Im not sure exactly what your beliefs are and im not here to ridicule you out of them, but how old do you believe the earth to be?

Well you have to keep in mind the enormous amount of time this all took place in. it is such a long time thats its hard for us to really conceptualize 5 million years or longer, what do you think about when thinking that 100 million years have passed? That doesnt mean anything to most of us. So what exactly are you looking for? There really isnt many other theories, youre free to go with creationism but that involves believing an all powerful mad scientist created everything with a snap of the fingers.

I don't believe in Creationism actually, but I also don't believe that just because evolution is practically the only other option should mean that I have to accept it as fact. I think scientists just can't accept that they really don't know. Also, I really don't think the earth is that old.

Well it is possible that they are wrong, but until proven wrong it is perfectly safe to go with the current theory. Im not sure exactly what your beliefs are and im not here to ridicule you out of them, but how old do you believe the earth to be?

That's just another problem. We don't know how the earth was formed, as the big bang makes more or less no sense, and therefore we cannot age the earth. So I'd say maybe in the tens of millions at most, but certainly not billions. I don't have many theories to be believe in, as you may have noticed.

The Earth is only 10s of millions of years old.
10s of Millions of years old
You really said that.
HELL. FREAKIN'. NO!
Are you saying the Earth was created after the Dinosaurs came about because of 10s of millions of years of evolution?
REALLY?
That's possible to have a species on a planet before it was created? Never knew that.
I knew the Earth was at least 100s of millions years old when I was 4. I studied Dinosaurs, and could recite facts about many of them, name a lot of them, and know what they ate (generalized of course into herbivore, carnivore) so I knew the first dinosaurs were well before 100 million BC. That's like the Jurrasic, which was the second dinosaur period I think. (I stopped studying dinos in Grade 4)

The Earth is at least a billion years old, the universe, from the microwave radiation left over from the Big Bang puts the universe at around 13.7 billion years old.

Grade 9 educations ftw.

 

[insanelich]

Also I'm all for healthy skepticism of the divine mandate of Science!, but there's also the thing called doubting too much. We have plenty of data that supports evolution, unlike, say, string theory or big bang. Data that should be considered rather than outright dismissing it in a fashion very reminiscent of "it's not in the book, it never happened".

And I think creationists and skeptics are treated by pro-evolutionists as "it's in the {science} book, it must have happened"

No, they're being treated like aggravating idiots. Science still doesn't deal in absolute truth - nor non-causal one-off subjects, to blast the other side!

 

[Ancientgamer]

I'm skeptical, to me the argument seems to be based on the magical ingredient"time" .
All the theories have such massive holes in them I find it irresponsible to just accept it as "fact"

A theory in science is different from the standard idea of a theory.

In science, a theory is a hypothesis that has large amounts of evidence to support it and little evidence that works against it. The theory of evolution has large amounts of supporting evidence and little evidence working against it.

Also it's not time that causes evolution. It's the slight genetic differences from one generation and another. It's just that you only notice these genetic differences when you compare a species to it's ancient relatives. Then you can see how over time these gradual genetic variations eventually led to massive changes.

But I've never seen a satisfactory explanation for how life started in the first place.

 

[Dando Dangerslice]

But I've never seen a satisfactory explanation for how life started in the first place.

there was one on the first page of this thread

 

[insanelich]

The Earth is at least a billion years old, the universe, from the microwave radiation left over from the Big Bang puts the universe at around 13.7 billion years old.

Grade 9 educations ftw.

Your grade 9 educations have unfortunately left you a little on the less scientific side - but don't worry, that happens to apparently 90% of the Wikipedia-editing public and half of the scientific community.

The microwave radiation from the Big Bang puts the observable universe at at least 13.7 billion years old. While some people do comprehend that from the original, the general public probably won't. See, it's easy.

 

[Alex_P]

I'm skeptical, to me the argument seems to be based on the magical ingredient"time" .
All the theories have such massive holes in them I find it irresponsible to just accept it as "fact"

Lots of time isn't a "magical ingredient". It just results in more iterations of the same process. A process that's pretty easy to understand and model if you have some background in, say, information theory.

There's not really any kind of gulf between "micro" and "macro" evolution -- they're pretty much just arbitrary categories for talking about the same process on different time scales.

-- Alex