You have the time scale so wrong. Keep in mind the extinctions. But that is the key. What fuels Speciation is open niches. The last great extinction 65 million years ago left about a third of life on the planet extinct. However it life bounced back in the hundreds of thousands of years. On average 1 in ~2 species had a speciation event over a time span less then a million years. But as said before that's because there was no competition. We see the same pattern after every mass exstiction

lucek wrote:You have the time scale so wrong. Keep in mind the extinctions. But that is the key. What fuels Speciation is open niches. The last great extinction 65 million years ago left about a third of life on the planet extinct. However it life bounced back in the hundreds of thousands of years. On average 1 in ~2 species had a speciation event over a time span less then a million years. But as said before that's because there was no competition. We see the same pattern after every mass exstiction

Yes and no. Empty niches are not necessarily filled quickly. Sometimes it may take 10, or 20 millions years for most of them to be re-occupied. Secondly, there are many ways for speciation to happen. It pretty much depends on what caused the disaster.

Darwinsbulldog wrote:

lucek wrote:You have the time scale so wrong. Keep in mind the extinctions. But that is the key. What fuels Speciation is open niches. The last great extinction 65 million years ago left about a third of life on the planet extinct. However it life bounced back in the hundreds of thousands of years. On average 1 in ~2 species had a speciation event over a time span less then a million years. But as said before that's because there was no competition. We see the same pattern after every mass exstiction

Yes and no. Empty niches are not necessarily filled quickly. Sometimes it may take 10, or 20 millions years for most of them to be re-occupied. Secondly, there are many ways for speciation to happen. It pretty much depends on what caused the disaster.

Generalizations of course. The large plesiosaurs for example didn't really have a replacement till sea mammals. Point was that most diversification happen shortly after such events.

Darwinsbulldog wrote:

Briton wrote:Multi-cellular life has only been around for about 500 million years hasn't it? Then there are the mass extinctions to factor in.

More like two billion years. Most of the time they were too small or soft-bodied to be obvious/common fossils.
Mass extinction will empty a lot of niches, although it is true these niches take a little longer to refill than previously thought.

I stand corrected.

drkfuture wrote:I wud like to know if speciation really occurs (trans-speciation), Have we had enough time for millions of species?

Yes. Because what matters, according to numerous experimental studies on the subject, including those published by Theodosius Dobzhansky in Nature, is generational turnaround. In short, organisms with fast life cycles (and most of the organisms on the planet fall into that category) can have multiple generations in a single year - for example, Drosophila melanogaster has a life cycle that is completed in just 18 to 25 days, depending upon temperature, and as a consequence, this species can produce as many as 18 generations in a single year.

Other insect species, such as Rhagoletis pomonella, have demonstrated that speciation can take place in less than 100 years, even if no other mechanism than genetic drift is active. Indeed, Dobzhansky produced an incipient speciation event in a laboratory population of Drosophila pseudoobscura in less than five years, which was placed upon a sound evidential basis because the laboratory population became reproductively incompatible with the wild type organisms in that time. More recently, Diane Dodd demonstrated that it was possible to generate an incipient speciation event in Drosophila fruit flies in as little as 18 months, and her experiment can be replicated by anyone who exercises the relevant methodological diligence, with nothing more than a greenhouse in which to culture the flies. Dodd's incipient speciation experiment can be run in a secondary school laboratory - if the experiment is begun when the pupils are 11 years old, there will be demonstrable assortative mating by the time those pupils are 12½, and reproductive incompatibility will start to manifest itself between the experimental populations by the time those pupils are 14.

Note that insects happen to be the most diverse clade on the planet - there are over 1.2 million species known to science, and that number is increasing at the rate of approximately one new species described per day. It's estimated that by the time the cataloguing is complete, the total number of known insect species could exceed 10 million. Lo and behold, most insects have short life cycles and rapid generational turnaround.

For that matter, I have in my collection a scientific paper, demonstrating that significant evolutionary changes can take place in vertebrates in the space of just 30 generations, courtesy of experimental observations of Croatian lizards belonging to the species Podarcis sicula. Likewise, Cichlid fishes have demonstrated their ability to speciate explosively in African Rift Lakes, the Lake Victoria Superflock being just 12,000 years old, yet, thanks to another paper in my collection, having been demonstrated via molecular phylogeny all to have arisen from an ancestral population of Haplochromis gracilior from nearby Lake Kivu.

With this data available, the idea that 3.5 billion years isn't enough to produce the biodiversity we observe, is clearly a non-starter.

Oh, and by the way, multicellular eukaryotes put in an appearance long before the Cambrian. Another paper in my collection describes Bangiomorpha pubescens, a sexually reproducing multicellular eukaryote dating back 1.2 billion years before present - nearly 700 million years before the Cambrian.

I've also presented a paper here in which scientists not only determined that a speciation event was responsible for the emergence of Heliconius heurippa butterflies in South America, but replicated that speciation event in the laboratory in the space of less than a year.

I think this should answer your question conclusively.

drkfuture wrote:The slow changes in traits in organisms, taking tens of thousands of years to yield a visible change in variation as evolution suggests

Except that the above data demonstrates that this view, originating 150 years ago, is now hopelessly outdated. Indeed, one only has to look at the history of the cultivation of Betta splendens, the Siamese Fighting Fish, in the aquarium, to know that significant changes can appear in short time spans. The Double Tail mutation (which, incidentally, exhibits classic Mendelian single-factor inheritance), first appeared in the early 1970s, and has since been replicated in tens of thousands of aquarium fish. In the space of less than a century, humans have driven, by appropriate positive selection, the fixing of over ten thousand different colour and finnage mutations in this species.

drkfuture wrote:does eventually trap yourself in to a problem of "Time Riddle" - you just dont have enormous enough of time at hand for all these species to come into being.

Wrong. See above.

drkfuture wrote:A quick average time calculation suggests that you should have a new species come into being every 15-20 yrs [just rough average time estimation suggests that in about 1 billion yrs ~50 million distinct species evolved].

Actually, in some lineages, the speciation fixation time is less than one year. It's even faster in some single celled lineages, which produce new generations once every 36 hours.

drkfuture wrote:Though I believe in evolution

Evolution isn't a matter of "belief", it's a matter of hard empirical evidence. How many of the 3,000 plus scientific papers in my collection do you want me to bring here to reinforce this?

drkfuture wrote:but I cant understand this part.

See above.

Spearthrower wrote:I'd really appreciate to know whether we've helped the OP clarify this, or whether he still has some concerns.

Well I don't know about the OP but I can't find the post in the thread where it was explained how long it takes for a given "what's it" to spectate. It seems to me that piece of information is critical in any calculation of how much time is enough ...

John Platko wrote:

Spearthrower wrote:I'd really appreciate to know whether we've helped the OP clarify this, or whether he still has some concerns.

Well I don't know about the OP but I can't find the post in the thread where it was explained how long it takes for a given "what's it" to spectate. It seems to me that piece of information is critical in any calculation of how much time is enough ...

Read my above post.

Here's some papers that are relevant here:

Evidence For Rapid Speciation Following A Founder Event In The Laboratory by James R. Weinberg Victoria R. Starczak and Danielle Jörg, Evolution 46: 1214-1220 (15th January 1992)

Experimentally Created Incipient Species Of Drosophila by Theodosius Dobzhansky & Olga Pavlovsky, Nature 230: 289 - 292 (2nd April 1971)

Founder-Flush Speciation On Drosophila pseudoobscura: A Large Scale Experiment by Agustí Galiana, Andrés Moya and Francisco J. Alaya, Evolution 47: 432-444 (1993)

Hybridisation And Adaptive Radiation by Ole Seehausen, TRENDS In Ecology & Evolution, 19(4): 198-207 (April 2004)

Incipient Speciation By Sexual Isolation in Drosophila: Concurrent Evolution At Multiple Loci by Chau-Ti Ting, Aya Takahashi and Chung-I Wu, Proceedings of the National Academy of Sciences of the USA, 98(12): 6709-6713 (5th June 2001)

Laboratory Experiments On Speciation: What Have We Learned In 40 Years? by William R. Rice and Ellen E. Hostert, Evolution, 47(6):1637-1653 (December 1993)

Rapid Evolution Of Postzygotic Reproductive Isolation In Stalk-Eyed Flies by Sarah J. Christianson, John G. Swallow and Gerald S. Wilkinson, Evolution, 59(4): 849-857 (12th January 2005)

Reproductive Isolation As A Consequence Of Adaptive Divergence In Drosophila pseudoobscura by Diane M. B. Dodd, Evolution, 43(6): 1308-1311 (September 1989)

Sexual Selection, Reproductive Isolation And The Genic View Of Speciation by J. J. M. Van Alphen and Ole Seehausen, Journal of Evolutionary Biology, 14: 874-875 (2001)

Speciation By Hybridisation In Heliconius Butterflies by Jesús Mavárez, Camilo A. Salazar, Eldredge Bermingham, Christian Salcedo, Chris D. Jiggins and Mauricio Linares, Nature, 441: 868-871 (15th June 2006)

What Does Drosophila Genetics Tell Us About Speciation? by James Mallet, TRENDS in Ecology & Evolution, 21(7): 386-393 (July 2006)

John Platko wrote:

Spearthrower wrote:I'd really appreciate to know whether we've helped the OP clarify this, or whether he still has some concerns.

Well I don't know about the OP but I can't find the post in the thread where it was explained how long it takes for a given "what's it" to spectate. It seems to me that piece of information is critical in any calculation of how much time is enough ...

You can't really calculate it simply by time, but by generations. Obviously, species which reach sexual maturity and reproduce in shorter time frames can speciate more rapidly than species which take longer. This is why bacteria and fruit flies are the most useful for lab experimentation as we actually have the opportunity to see speciation occur within a human life-span.

Also, selection pressures may be stronger or weaker between different species, so there's no hard rule - an organism which inhabits a niche that doesn't change much (i.e. climate, availability of food, number of predators etc) still changes over time, but less than one which is facing environmental pressures.

Finally, there's also the role of sheer chance. A population which experiences a 'sudden' reproductive barrier between parts of its population will more rapidly speciate as the two pools of genes will evolve independently - this is 'ecological speciation' or 'rapid evolution'.

So the answer to your question is 'it depends'!

What can also happen is natural saltation -the emergence of a new and successful body plan from a minute genetic change. Snail chirility, Testudines evolution, and bilateral symmetry itself. Although rare, they can be of great impact.

Spearthrower wrote:

John Platko wrote:

Spearthrower wrote:I'd really appreciate to know whether we've helped the OP clarify this, or whether he still has some concerns.

Well I don't know about the OP but I can't find the post in the thread where it was explained how long it takes for a given "what's it" to spectate. It seems to me that piece of information is critical in any calculation of how much time is enough ...

You can't really calculate it simply by time, but by generations. Obviously, species which reach sexual maturity and reproduce in shorter time frames can speciate more rapidly than species which take longer. This is why bacteria and fruit flies are the most useful for lab experimentation as we actually have the opportunity to see speciation occur within a human life-span.

Also, selection pressures may be stronger or weaker between different species, so there's no hard rule - an organism which inhabits a niche that doesn't change much (i.e. climate, availability of food, number of predators etc) still changes over time, but less than one which is facing environmental pressures.

Finally, there's also the role of sheer chance. A population which experiences a 'sudden' reproductive barrier between parts of its population will more rapidly speciate as the two pools of genes will evolve independently - this is 'ecological speciation' or 'rapid evolution'.

So the answer to your question is 'it depends'!

I had a hunch something like that was afoot.

So demonstrations of the power of exponential growth can't prove that there has been enough time because an "it depends" is part of the equation - and anecdotal information about flies and the other simple creatures doesn't really close the case because your millage may vary with much more complex and/or different species.

On the other hand, my hunch is that if there wasn't enough time then we wouldn't be here. I find that to be a more convincing line of argument.

John Platko wrote:I had a hunch something like that was afoot.

So demonstrations of the power of exponential growth can't prove that there has been enough time because an "it depends" is part of the equation - and anecdotal information about flies and the other simple creatures doesn't really close the case because your millage may vary with much more complex and/or different species.

Except if the claim is merely "There could be enough time," that is sufficient to demonstrate the claim is true. Whereas someone claiming "There could not have been enough time" has considerably more work left to do.

On the other hand, my hunch is that if there wasn't enough time then we wouldn't be here. I find that to be a more convincing line of argument.

John Platko wrote:

Spearthrower wrote:

John Platko wrote:

Spearthrower wrote:I'd really appreciate to know whether we've helped the OP clarify this, or whether he still has some concerns.

Well I don't know about the OP but I can't find the post in the thread where it was explained how long it takes for a given "what's it" to spectate. It seems to me that piece of information is critical in any calculation of how much time is enough ...

You can't really calculate it simply by time, but by generations. Obviously, species which reach sexual maturity and reproduce in shorter time frames can speciate more rapidly than species which take longer. This is why bacteria and fruit flies are the most useful for lab experimentation as we actually have the opportunity to see speciation occur within a human life-span.

Also, selection pressures may be stronger or weaker between different species, so there's no hard rule - an organism which inhabits a niche that doesn't change much (i.e. climate, availability of food, number of predators etc) still changes over time, but less than one which is facing environmental pressures.

Finally, there's also the role of sheer chance. A population which experiences a 'sudden' reproductive barrier between parts of its population will more rapidly speciate as the two pools of genes will evolve independently - this is 'ecological speciation' or 'rapid evolution'.

So the answer to your question is 'it depends'!

I had a hunch something like that was afoot.

So demonstrations of the power of exponential growth can't prove that there has been enough time because an "it depends" is part of the equation - and anecdotal information about flies and the other simple creatures doesn't really close the case because your millage may vary with much more complex and/or different species.

On the other hand, my hunch is that if there wasn't enough time then we wouldn't be here. I find that to be a more convincing line of argument.

Your logic is wrong there John. To show something is possible would only require taking the very lowest possible value of the "it depends", which is actually massively shorter than the, for example, million years I used.

John Platko wrote:

Spearthrower wrote:

John Platko wrote:

Spearthrower wrote:I'd really appreciate to know whether we've helped the OP clarify this, or whether he still has some concerns.

Well I don't know about the OP but I can't find the post in the thread where it was explained how long it takes for a given "what's it" to spectate. It seems to me that piece of information is critical in any calculation of how much time is enough ...

You can't really calculate it simply by time, but by generations. Obviously, species which reach sexual maturity and reproduce in shorter time frames can speciate more rapidly than species which take longer. This is why bacteria and fruit flies are the most useful for lab experimentation as we actually have the opportunity to see speciation occur within a human life-span.

Also, selection pressures may be stronger or weaker between different species, so there's no hard rule - an organism which inhabits a niche that doesn't change much (i.e. climate, availability of food, number of predators etc) still changes over time, but less than one which is facing environmental pressures.

Finally, there's also the role of sheer chance. A population which experiences a 'sudden' reproductive barrier between parts of its population will more rapidly speciate as the two pools of genes will evolve independently - this is 'ecological speciation' or 'rapid evolution'.

So the answer to your question is 'it depends'!

I had a hunch something like that was afoot.

So demonstrations of the power of exponential growth can't prove that there has been enough time because an "it depends" is part of the equation - and anecdotal information about flies and the other simple creatures doesn't really close the case because your millage may vary with much more complex and/or different species.

On the other hand, my hunch is that if there wasn't enough time then we wouldn't be here. I find that to be a more convincing line of argument.

It's all too common for people to be fuddled in their understanding of the actual factors at play, yet somehow find circular logic to be more compelling. That's one of the reasons we do science, because hunches frequently turn out to be highly inaccurate affairs, exhibiting more about the possessor of the hunch's psychology than the natural phenomenon which needs to be explained.

'It depends' doesn't mean 'we don't know' - it means exactly what it says: it depends on the species. So, if you want to calculate the sum total of speciation events across all life from year dot perfectly accurately, you're going to need to make independent calculations of all those hundreds of millions of species independently then combine the result.

Unless you are being paid to do that, or have an inordinate amount of time on your hands, I doubt anyone's going to be sufficiently motivated to arrive at perfect accuracy.

However, we have plenty of lines of evidence which supply us with good ball park figures we can use to extrapolate.

Perhaps your response might have been better if you'd asked for lines of evidence rather than the above woefully misguided glee. Incidentally, you might also want to look up the word 'anecdotal', because that word is not accurate when used to refer to scientific experimentation.

Thommo wrote:

John Platko wrote:

Spearthrower wrote:

John Platko wrote:

Well I don't know about the OP but I can't find the post in the thread where it was explained how long it takes for a given "what's it" to spectate. It seems to me that piece of information is critical in any calculation of how much time is enough ...

You can't really calculate it simply by time, but by generations. Obviously, species which reach sexual maturity and reproduce in shorter time frames can speciate more rapidly than species which take longer. This is why bacteria and fruit flies are the most useful for lab experimentation as we actually have the opportunity to see speciation occur within a human life-span.

Also, selection pressures may be stronger or weaker between different species, so there's no hard rule - an organism which inhabits a niche that doesn't change much (i.e. climate, availability of food, number of predators etc) still changes over time, but less than one which is facing environmental pressures.

Finally, there's also the role of sheer chance. A population which experiences a 'sudden' reproductive barrier between parts of its population will more rapidly speciate as the two pools of genes will evolve independently - this is 'ecological speciation' or 'rapid evolution'.

So the answer to your question is 'it depends'!

I had a hunch something like that was afoot.

So demonstrations of the power of exponential growth can't prove that there has been enough time because an "it depends" is part of the equation - and anecdotal information about flies and the other simple creatures doesn't really close the case because your millage may vary with much more complex and/or different species.

On the other hand, my hunch is that if there wasn't enough time then we wouldn't be here. I find that to be a more convincing line of argument.

Your logic is wrong there John. To show something is possible would only require taking the very lowest possible value of the "it depends", which is actually massively shorter than the, for example, million years I used.

But we don't know the "very lowest possible value of the "it depends", for many/most branches of the evolutionary tree- right?

John Platko wrote:

Thommo wrote:

John Platko wrote:

Spearthrower wrote:


You can't really calculate it simply by time, but by generations. Obviously, species which reach sexual maturity and reproduce in shorter time frames can speciate more rapidly than species which take longer. This is why bacteria and fruit flies are the most useful for lab experimentation as we actually have the opportunity to see speciation occur within a human life-span.

Also, selection pressures may be stronger or weaker between different species, so there's no hard rule - an organism which inhabits a niche that doesn't change much (i.e. climate, availability of food, number of predators etc) still changes over time, but less than one which is facing environmental pressures.

Finally, there's also the role of sheer chance. A population which experiences a 'sudden' reproductive barrier between parts of its population will more rapidly speciate as the two pools of genes will evolve independently - this is 'ecological speciation' or 'rapid evolution'.

So the answer to your question is 'it depends'!

I had a hunch something like that was afoot.

So demonstrations of the power of exponential growth can't prove that there has been enough time because an "it depends" is part of the equation - and anecdotal information about flies and the other simple creatures doesn't really close the case because your millage may vary with much more complex and/or different species.

On the other hand, my hunch is that if there wasn't enough time then we wouldn't be here. I find that to be a more convincing line of argument.

Your logic is wrong there John. To show something is possible would only require taking the very lowest possible value of the "it depends", which is actually massively shorter than the, for example, million years I used.

But we don't know the "very lowest possible value of the "it depends", for many/most branches of the evolutionary tree- right?

It doesn't matter, because we know that the lowest possible is far less than a million years (e.g. fruit flies can speciate in less than a hundred), so we've hedged very much on the safe side. We have shown that it is possible to get far more species than there are actually are, within the time available.

This addresses the question in the OP regarding the "time riddle" entirely.

Spearthrower wrote:

John Platko wrote:

Spearthrower wrote:

John Platko wrote:

Well I don't know about the OP but I can't find the post in the thread where it was explained how long it takes for a given "what's it" to spectate. It seems to me that piece of information is critical in any calculation of how much time is enough ...

You can't really calculate it simply by time, but by generations. Obviously, species which reach sexual maturity and reproduce in shorter time frames can speciate more rapidly than species which take longer. This is why bacteria and fruit flies are the most useful for lab experimentation as we actually have the opportunity to see speciation occur within a human life-span.

Also, selection pressures may be stronger or weaker between different species, so there's no hard rule - an organism which inhabits a niche that doesn't change much (i.e. climate, availability of food, number of predators etc) still changes over time, but less than one which is facing environmental pressures.

Finally, there's also the role of sheer chance. A population which experiences a 'sudden' reproductive barrier between parts of its population will more rapidly speciate as the two pools of genes will evolve independently - this is 'ecological speciation' or 'rapid evolution'.

So the answer to your question is 'it depends'!

I had a hunch something like that was afoot.

So demonstrations of the power of exponential growth can't prove that there has been enough time because an "it depends" is part of the equation - and anecdotal information about flies and the other simple creatures doesn't really close the case because your millage may vary with much more complex and/or different species.

On the other hand, my hunch is that if there wasn't enough time then we wouldn't be here. I find that to be a more convincing line of argument.

It's all too common for people to be fuddled in their understanding of the actual factors at play, yet somehow find circular logic to be more compelling. That's one of the reasons we do science, because hunches frequently turn out to be highly inaccurate affairs, exhibiting more about the possessor of the hunch's psychology than the natural phenomenon which needs to be explained.

Indeed. That's certainly one of the many fine points emphasized over and over again in Sapolsky's course. Scientific "hunches" often turn out to be wrong- with dire consequences for many along the way.

'It depends' doesn't mean 'we don't know' - it means exactly what it says: it depends on the species. So, if you want to calculate the sum total of speciation events across all life from year dot perfectly accurately, you're going to need to make independent calculations of all those hundreds of millions of species independently then combine the result.

I got that. It was the point of my comment. Where's the chart that shows the lower and upper probability bound for each species?

Unless you are being paid to do that, or have an inordinate amount of time on your hands, I doubt anyone's going to be sufficiently motivated to arrive at perfect accuracy.

I'm not looking for perfection, just something better than "see how fast flies speciaciate, extrapolating from there we have ... Where are the numbers for the more complex species and how were they determined?

However, we have plenty of lines of evidence which supply us with good ball park figures we can use to extrapolate.

Great! Please explain the whys and hows of speciation of high order creatures.

Perhaps your response might have been better if you'd asked for lines of evidence rather than the above woefully misguided glee. Incidentally, you might also want to look up the word 'anecdotal', because that word is not accurate when used to refer to scientific experimentation.

I was merely pointing out the flaw I saw in the line of argument. I find that looking in the mirror is all the evidence I really need to know there was enough time for all of this to happen. On the other hand, I've been told more than once that I'm gullible.

Read those scientific papers I cited, John. Several of which document speciation events taking place in five years or less in relevant lineages.

Calilasseia wrote:Read those scientific papers I cited, John. Several of which document speciation events taking place in five years or less in relevant lineages.

Would you please point out which of these papers:

Here's some papers that are relevant here:

Evidence For Rapid Speciation Following A Founder Event In The Laboratory by James R. Weinberg Victoria R. Starczak and Danielle Jörg, Evolution 46: 1214-1220 (15th January 1992)

Experimentally Created Incipient Species Of Drosophila by Theodosius Dobzhansky & Olga Pavlovsky, Nature 230: 289 - 292 (2nd April 1971)

Founder-Flush Speciation On Drosophila pseudoobscura: A Large Scale Experiment by Agustí Galiana, Andrés Moya and Francisco J. Alaya, Evolution 47: 432-444 (1993)

Hybridisation And Adaptive Radiation by Ole Seehausen, TRENDS In Ecology & Evolution, 19(4): 198-207 (April 2004)

Incipient Speciation By Sexual Isolation in Drosophila: Concurrent Evolution At Multiple Loci by Chau-Ti Ting, Aya Takahashi and Chung-I Wu, Proceedings of the National Academy of Sciences of the USA, 98(12): 6709-6713 (5th June 2001)

Laboratory Experiments On Speciation: What Have We Learned In 40 Years? by William R. Rice and Ellen E. Hostert, Evolution, 47(6):1637-1653 (December 1993)

Rapid Evolution Of Postzygotic Reproductive Isolation In Stalk-Eyed Flies by Sarah J. Christianson, John G. Swallow and Gerald S. Wilkinson, Evolution, 59(4): 849-857 (12th January 2005)

Reproductive Isolation As A Consequence Of Adaptive Divergence In Drosophila pseudoobscura by Diane M. B. Dodd, Evolution, 43(6): 1308-1311 (September 1989)

Sexual Selection, Reproductive Isolation And The Genic View Of Speciation by J. J. M. Van Alphen and Ole Seehausen, Journal of Evolutionary Biology, 14: 874-875 (2001)

Speciation By Hybridisation In Heliconius Butterflies by Jesús Mavárez, Camilo A. Salazar, Eldredge Bermingham, Christian Salcedo, Chris D. Jiggins and Mauricio Linares, Nature, 441: 868-871 (15th June 2006)

What Does Drosophila Genetics Tell Us About Speciation? by James Mallet, TRENDS in Ecology & Evolution, 21(7): 386-393 (July 2006)

are obviously relevant to speciation of higher order animals? It may be obvious to someone steeped in the science but for an outsider like me it's hard to see what the mathematical relationship between fly evolution and the evolution of a more complex animal is.

Hmmmmm. It looks complicated. Very very complicated ....

http://mbe.oxfordjournals.org/content/32/4/835.full

John Platko wrote:Indeed. That's certainly one of the many fine points emphasized over and over again in Sapolsky's course. Scientific "hunches" often turn out to be wrong- with dire consequences for many along the way.

The only 'hunch' so far employed in this thread is yours, and it wasn't scientific, so this is irrelevant.

Scientific hunches are inferences, but science cannot stop at the hypothesis - it must needs check its contents against observation and experimentation.

Finally, while the drama of your sentence is certainly entertaining, it also appears to be fantasy. Would you care to supply a single example of a 'scientific hunch' which turned out to have 'dire consequences for many'?

John Platko wrote:

Spearthrower wrote:

'It depends' doesn't mean 'we don't know' - it means exactly what it says: it depends on the species. So, if you want to calculate the sum total of speciation events across all life from year dot perfectly accurately, you're going to need to make independent calculations of all those hundreds of millions of species independently then combine the result.

I got that. It was the point of my comment.

No, you clearly didn't get that, or you wouldn't have taken 'it depends' to mean 'we don't know'. Note that I was talking specifically about the speciation of a species - it depends because it's the same format of question as 'how long is a piece of string'. Whereas, my post made it clear for you that, while it depends on the organism, it is not 'unknown'.

John Platko wrote: Where's the chart that shows the lower and upper probability bound for each species?

Why would there be a chart, Platko?

Did you really read my post you're supposedly replying to?

John Platko wrote:

Spearthrower wrote:
Unless you are being paid to do that, or have an inordinate amount of time on your hands, I doubt anyone's going to be sufficiently motivated to arrive at perfect accuracy.

I'm not looking for perfection,....

Says you who just asked for a chart!

John Platko wrote:just something better than "see how fast flies speciaciate, extrapolating from there we have ...

And yet no one said that. I clearly used the fruit flies as an example of how speciation can be measured. I did not say that we extrapolate from fruit fly speciation.

John Platko wrote:Where are the numbers for the more complex species and how were they determined?

Before getting to that - what do you mean 'more complex'? It's a wooly notion. Do you mean 'bigger'? Do you mean 'possesses more active DNA'?

As for where the numbers are, you need to read relevant scientific journals.

For example:

http://www.ncbi.nlm.nih.gov/pubmed/24299412

Quantifying variation in speciation and extinction rates with clade data.
Paradis E, Tedesco PA, Hugueny B.

http://www.ncbi.nlm.nih.gov/pubmed/20525614

Heritability of extinction rates links diversification patterns in molecular phylogenies and fossils.
Rabosky DL.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2605086/

The speed of ecological speciation
ANDREW P. HENDRY,*† PATRIK NOSIL,‡ and LOREN H. RIESEBERG§


As you mention in a following post, you're an 'outsider', so I can also suggest that when you look at a paper like this, scroll on down to the references - science builds on previous observations and data and needs to take those into account too.

So, for example, the last citation there has 73 papers referenced all with information pertaining to speciation rates and means of quantifying them.

But you can't expect a specific question to be specifically addressed in a single paper. If you want that to happen, you have to do it yourself, old chap! It's a monumental task considering there have been billions of species in Earth's history, and I doubt very much you'd really want to read a paper that did attempt to list each and every speciation event and the time it took - worse than all those begats in your book!

John Platko wrote:

Spearthrower wrote:
However, we have plenty of lines of evidence which supply us with good ball park figures we can use to extrapolate.

Great! Please explain the whys and hows of speciation of high order creatures.

First, you'll need to explain to me what 'higher order creatures' means. Also, by 'hows' and 'whys' do you mean how speciation occurs, as in, what the forces are affecting it?

John Platko wrote:

Spearthrower wrote:

Perhaps your response might have been better if you'd asked for lines of evidence rather than the above woefully misguided glee. Incidentally, you might also want to look up the word 'anecdotal', because that word is not accurate when used to refer to scientific experimentation.

I was merely pointing out the flaw I saw in the line of argument.

It was misidentified as a flaw because the correct answer to 'how long is a piece of string' is - it depends. Whereas, how long is 'that' piece of string is an answerable question, as is finding out the average length of a piece of string from among a drawer full of pieces of string.

John Platko wrote:I find that looking in the mirror is all the evidence I really need to know there was enough time for all of this to happen. On the other hand, I've been told more than once that I'm gullible.

As I said: that's circular reasoning, and as an adherent to a magical belief system, you actually have no such restrictions in play. If God made it all last Wednesday, you would likewise be obliged to consider that there was enough time for all this to happen.

However, the question itself is actually important, and was first posed back in the Victorian era to contest the Darwinian account. It took nearly a century before we had enough data to really answer that question, but now we can safely say that the question long since stopped being 'is there enough time', and instead became: 'so where are they all?' And this is what first gave us insight and research directives into exploring extinction rates - which had previously been greatly undervalued.