How long does speciation typically take?

[Deetee]

I know it doesn't answer your original question, but it used to take a beetle about 3-4 days to develop into a new species.

The flood was 6000 years ago.
Noah took only one "kind" of ancestral beetle on the ark.
Accurate documentation of types of beetle go back around 2000 years or more, and there appear not to have been any changes between then and the same species described now, so we can assume speciation strangely stopped after a 4000 year or so microevolutionary burst.
There are 300 000 or so species of beetle around today, so assume there were that number 2000 years ago.
Even ignoring the fact that many species may have become extinct in the last 6000 years or so, the rate of post-deluvian speciation would appear to average one species every 3-4 days.

 

[Dave1001]

Try enough chimp/human matings, and you just might get one to take --

Really? This deserves it's own thread if it's truly a debatable idea.

 

[Jon the Geek]

I am afraid this interpretation of speciation is incorrect. Remember that the species we see today are the result of many generations of evolutionary pressure selecting for certain characteristics. Consider a series of generations of species A (so that A1 is the first generation A2 the second etc).

Duh, thanks. I felt like there was a hole in my logic somewhere, but couldn't figure out where. It's like the language analogy: I can speak to my dad, and he can speak to his, etc, going back as many generations as you care to go back... but if I go back 500 years, I find a completely different language.

 

[Dave1001]

Duh, thanks. I felt like there was a hole in my logic somewhere, but couldn't figure out where. It's like the language analogy: I can speak to my dad, and he can speak to his, etc, going back as many generations as you care to go back... but if I go back 500 years, I find a completely different language.

That's a pretty good analogy. Although of course, not so much a completely different language, as a language which you can no longer communicate with them. Kind of like species that can't mate despite a common ancestor.

It is a good question whether there can be a single generation in the ability to mate break, or if it's just populations diverging in isolation to each other, and by the time they reunite they have diverged sufficiently so that they are unable to procreate. Of course, I imagine this "good question" has probably been answered by scientists.

 

[Soapy Sam]

Take a minimalist example.

Creature Q, a member of species A, has a mutation that renders it unable to breed with members of species A. We need change nothing else.

Is it a new species, or merely an infertile member of species A?

Indeed, is there a difference?

Q has nobody to breed with. He will die without issue, or he will go extinct, depending on whether you define him as an individual, or a species.

This , I think, rules out single generation speciation, if we define species by cross-fertility.

A single generation variety is perfectly possible, even commonplace.

The variation could easily be behavioural- Q starts eating carrion instead of nuts and berries for instance. If the behaviour is successful, Q breeds and some of his offspring and associates acquire the habit. That group behave differently enough from the rest of species A to form a distinct sub species- and that's where isolation starts to take effect. They may be perfectly able to interbreed with any of species A, but they tend to breed with a sub group. Note that no gene shift at all is required here. But after a while, it will start to happen, even if there is no physical barrier between the groups. The meat eaters start to select traits that are advantageous to meat eaters, but not to the traditionalists of sp.A.

After a number of generations, the cumulative effect of these changes may well include infertility between the groups, but unless the experiment is tried, it doesn't matter . Species is a human, functional, descriptive category and that's all it is. Cats don't know what species they are. I've seen a tomcat humping a sofa, for Ed's sake!

So the answer to the OP, as others have said, is " after a number of generations", which is a weasel kind of answer, but so far as I can see, correct.

 

[drkitten]

Take a minimalist example.

Creature Q, a member of species A, has a mutation that renders it unable to breed with members of species A. We need change nothing else.

Is it a new species, or merely an infertile member of species A?

Indeed, is there a difference?

Q has nobody to breed with. He will die without issue, or he will go extinct, depending on whether you define him as an individual, or a species.

Not necessarily.

Depending upon the type of mutation he has, there may be other members of the population that have similar mutations. All he has to do is find Miss Q' with whom he can breed.

Secondly, he may be able to reproduce asexually until he can mate with himself. Many plants can do this, for example reproducing via cuttings. I believe that the "peppermint" variety is actually entirely sterile -- there are no such things as peppermint seeds. But it's hardly dying out.

 

[phildonnia]

An interesting plant I found when reading on this topic:
http://en.wikipedia.org/wiki/Salsify

 

[Dr Adequate]

The SkepticWiki article on Creationist Arguments [swiki]No New Species Have Been Observed[/swiki] gives a number of examples of observed speciation.

The fish Mosquito refers to are cichlids, and it was thousands of years, not hundreds. Different cichlid populations can be found in several lakes in the Rift Valley, including Lakes Victoria, Tanganika, and Malawi.

 

[GodMark2]

I'm suprised that no one has yet brought up ring species.

http://en.wikipedia.org/wiki/Ring_species

Ring species are anathema to one of the underlying assumptions of the OP.

Namely, that if individual q ia a member of species Q, and individual y can successfully mate with q, and individual z can also mate with q, then y must be able to mate with z.

The only problem is that ring species show that this is not true. The definition of species of "All the things that can mate with each other, and not with others" just doesn't fit into the real world. So the question as posed is less than meaningful.

 

[sphenisc]

Ring species are anathema to one of the underlying assumptions of the OP.

Namely, that if individual q ia a member of species Q, and individual y can successfully mate with q, and individual z can also mate with q, then y must be able to mate with z.

QUOTE]

This scenario doesn't require ring species as a counter example, the existence of two sexes is sufficent.

In the situation

M1 = F1 = M2 = F2 = M3 = ....Fn-1 = Mn

(= is 'successfully mates with')

then ring species demonstrate that we can't conclude

M1 = Fn-1

 

[Mosquito]

The SkepticWiki article on Creationist Arguments [swiki]No New Species Have Been Observed[/swiki] gives a number of examples of observed speciation.

The fish Mosquito refers to are cichlids, and it was thousands of years, not hundreds. Different cichlid populations can be found in several lakes in the Rift Valley, including Lakes Victoria, Tanganika, and Malawi.

Ok, so my memory was a little off, but I was right also (within one order of magnitude, anyway), as can be seen in example 4 from http://www.talkorigins.org/faqs/speciation.html, also note example 3, only 250 years...

I still stand by my comment that evolution is fast when given the opportunity (i.e. available niches are easily adapted to).

A few thousand years is actually plenty time to evolve new species, if there is little restraint. Given the typical generation time of 1-2 years, this gives plenty of generations for mixing, mutating and selecting features into new species.

Mosquito - transitional form, I hope.

 

[Mojo]

Mosquito - transitional form, I hope.

There is, of course, the example discovered of mosquitos speciating on the London Underground.

 

[sphenisc]

There is, of course, the example discovered of mosquitos speciating on the London Underground.

As the London Underground was opened in 1863 that represents one speciation event in 143 years, i.e to go from one species to two.. If we take that as an average then after 286 years there would be four species, 572 years eight species and so on.

Current estimates for the number of species on the planet are vague, but 10^7 is a ballpark figure.
How long would it take to produce that many species ?
About 3,500 years.

Just saying

 

[Dave1001]

As the London Underground was opened in 1863 that represents one speciation event in 143 years, i.e to go from one species to two.. If we take that as an average then after 286 years there would be four species, 572 years eight species and so on.

Current estimates for the number of species on the planet are vague, but 10^7 is a ballpark figure.
How long would it take to produce that many species ?
About 3,500 years.

Just saying

You sir would make an excellent Creation Scientist.

 

[ponderingturtle]

The amount of time it takes for a trait to emerge is dependent upon many environmental and species specific variables. Generally speaking, extreme conditions that push a population close to extinction will "sharpen the edge" and really draw out the individuals with successful traits. So, evolution can speed up and slow down based on the environment. However a long cycle of reproduction and maturity might not allow a species enough time to adapt. Other variables are the complexity of the species' genome. Take almond trees for example. Wild almonds have a cyanide based compound in them. Domesticated almonds do no have this poisonous trait because of a genetic mutation at a single point in the genome. A simple on/off switch which was selected for and allowed humans to easily domesticate and farm almonds. Furthermore, Speciation requires a separation of a segment of a species from the rest of the species so that its adaptations do not become diluted so the segment can become a species in its own right. So, we might see an acceleration of speciation in large mamals because the various groups of a species population are being segergated into wildlife refuges.

There is no simple answer to your question. Speciation is a complex interaction of genetic and environmental variables.

The almond tree thing does not sound like speciation though, can domestic and wild almonds cross polinate?

 

[ponderingturtle]

Species is a very specific term. It means 2 animals that cannot interbreed and produce fertile offspring. This is not subject to interpretation and thin lines.

So lions and tigers are the same species? I know that a cross breed from them did successfuly breed with one of the parent species. So that would meet the fertile ofspring catagory.

 

[Skeptic Ginger]

I know it doesn't answer your original question, but it used to take a beetle about 3-4 days to develop into a new species.

The flood was 6000 years ago.
Noah took only one "kind" of ancestral beetle on the ark.
Accurate documentation of types of beetle go back around 2000 years or more, and there appear not to have been any changes between then and the same species described now, so we can assume speciation strangely stopped after a 4000 year or so microevolutionary burst.
There are 300 000 or so species of beetle around today, so assume there were that number 2000 years ago.
Even ignoring the fact that many species may have become extinct in the last 6000 years or so, the rate of post-deluvian speciation would appear to average one species every 3-4 days.

 

[Soapy Sam]

Drkitten- yes, if there is an abundant mutation in a gene pool, which happens to induce sterility (in both sexes, mind) , but permits fertilisation between mutants, you could have massive divergence in one generation- but you have to weigh that small possibility against the fact that any gene which makes its owner sterile has a very low chance of becoming abundant in the first place.
I agree it's possible, but it's a hopeful monster scenario- extremely unlikely among the sort of large animals / trees referred to by CplFerro. I can see it in a high- density insect population , maybe, but even then it seems very improbable.

 

[phildonnia]

Species is a very specific term. It means 2 animals that cannot interbreed and produce fertile offspring. This is not subject to interpretation and thin lines.

I can think of a few thin lines of interpretation, especially among species that can interbreed, but don't. For example, a gray wolf (Canis lupus lupus) and a dingo (Canis lupus dingo) can interbreed, but don't because of geographical separation. Yet they are consided to be varieties of the same species. On the other hand, asian pear (pyrus pyrifolia) and european pear (pyrus communis) can also interbreed, but they flower at different times. They are considered separate species. The difference seems to be whether the incompatibility is biological or not.

Someone mentioned lions and tigers; in general, these do not recognize each other as mates, and so are not biologically disposed to interbreed, despite the genetic compatibility.

 

[blutoski]

Species is a very specific term. It means 2 animals that cannot interbreed and produce fertile offspring. This is not subject to interpretation and thin lines.

No, as Dr. Richard pointed out, the biological concept of species is defined a little flexibly, depending on the task at hand. It is, after all, a human concept.

Many animals which are different species - or even different genera - can successfully form viable hybrids. Examples that come to mind immediately are finch genera, several canus species (lupus and familiaris), and several Felidae (Panthera tigris and Panthera leo are famous for producing "ligers").

To make things more complicated, some varieties of canus familiaris can't interbreed with others for mechanical reasons (which are technically genetic in origin), but are considered the same species.



The more popular working definition is that two animals are the same species if they produce viable offspring in the wild. Consequently, there are many biologically interbreedable species of birds which never interbreed because they have different mating calls, or different seasons.



Sphenicic pointed out that karyotype speciation is prety much instantaneous. The only thing necessary to produce a new population from this single speciation event is a mate with identical karyotype mutation.




To summarize an answer the thread question: it can take one generation for speciation to occur, or millions of years. Depends on how it happened. However, obviously, the more time that has passed, the more significantly different the specimens will be.

So, if the question is: how many generations did it take for this variety of wheat to become a seperate species from this other variety of wheat, and they're identical in every way in appearance, it wouldn't be surprising to learn that they have the same parent, but are incompatible siblings due to karyotype mutation.

Versus: how many generations did it take for Pan and Homo to become distinct from the Australopithecine line? They have significant differences, so you would predict longer, and this is observed in the fossil record.



That there is no good definition of species is actually evidence in support of evolution, since the theory predicts a gradual change. If species were concrete, the concept of biblical kinds would be a good explanation. However, when pressed on this, Creationists evade the issue. Specifically, I asked Kent Hovind about this once, and he fobbed it off with "Well, yes, a definition of kinds would be very valuable... This is a good subject for future research..."