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Author
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Topic: Speciation
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warren_bergerson
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Member # 262
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posted 25. April 2004 12:44
A follow-up thought on Rex’s comment: “I have difficulty translating his hypotheses into predictions that might discriminate his hypotheses from others”
All that is needed to demonstrate the validity of intelligent design hypotheses based on the ‘evolution controlled by purposeful intelligence’ or ‘speciation determined by purposeful intelligence’ concepts is to show that such hypotheses produce useful, reliable, and testable scientific predictions. At least initially, there is no need to prove that hypotheses based on intelligent design concepts are superior to predictive hypotheses based on alternative concepts. At least IMO, it would be appropriate to first establish that intelligent design based hypotheses can produce useful and testable predictions.
Once the validity of such predictive hypotheses has been established, then the question of the relative merits can be evaluated.
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Pim van Meurs
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Member # 541
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posted 25. April 2004 12:45
Nosivad, rather than showing support for his thesis, seems to ask for references to the countless examples of speciation in nature.
sitckle back speciation
Also stickleback
Salamander speciation
As far as your question about your contribution to 'Rivista di Biologia' not being taken seriously, perhaps this can be explained by the nature of the publication.
quote:
Rivista di biologia è la rivista personale di Sermonti. Non è peer reviewed, nel senso che non ha un gruppo di ricercatori che leggono i testi e li criticano per l'attendibilità.
Link
[ 25. April 2004, 12:53: Message edited by: Pim van Meurs ]
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Stuart Harris
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Member # 152
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posted 25. April 2004 12:53
Perhaps determining an estimate of the number of species that have ever existed would help. I've seen varying estimates, some going into the hundreds of trillions as being the amount of species that have come and gone over the history of evolution. Assuming a constant rate of speciation events, wouldn't we expect to be seeing at least thousands of new ones each year? Assumimg it's not constant and the biotic world is currently in a period of stasis, then in eras when active speciation is occuring there must be millions of speciation events per year.
And what is a "speciation event" precisely. When does the morphological contimuum break so that an indiviual is now a new species from its ancestors, or even from it's parent. And, in the case of sexual reproduction what does it mate with?!
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Pim van Meurs
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Member # 541
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posted 25. April 2004 13:01
Warren: All that is needed to demonstrate the validity of intelligent design hypotheses based on the ‘evolution controlled by purposeful intelligence’ or ‘speciation determined by purposeful intelligence’ concepts is to show that such hypotheses produce useful, reliable, and testable scientific predictions.
How is the validity of such hypotheses determined by 'useful, reliable and testable' predictions? What is needed are useful reliable and testable predictions that differentiate such hypotheses from non ID hypotheses.
In addition, reliable predictions need not be sufficient for the veracity of ID hypotheses when they do not address the ID part or do not place the ID part in jeopardy.
For instance Mike Gene uses front loading as a foundation for his 'predictions' relevant to ID but such predictions even if correct have little impact on the ID/non-ID issue.
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nosivad
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Member # 767
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posted 25. April 2004 16:42
Pim
Rivista is definitely peer reviewed. I happen to know from personal experience. If you can't attack the message, attack the messenger. As for the examples of speciation you have mentioned, my position right along is that obligatory sexual reproduction is incapable of exceeding the species barrier. For all I know speciation might be going on right now but I'll bet it is not resulting from either natural or artificial selection of mutations as the Darwinian model demands. The problem of a mate is no difficulty as it has already been experimentally documented that semi-meiosis can produce from the female genome both functional sexes. Besides that there is structural evidence indicating that the Y chromosome may not even be homologous in various related animals. In short as Vorontsov suggested:
"Against the background of these facts it is unclear whether the male species of different groups are homologous to each other or not; they appear to be nonhomologous".
I suggest that if the substance of my two hypotheses are in factual error that someone publish a rebuttal somewhere. Until that happens I will naturally assume that my critique of Darwinism has been ignored for precisely the same reasons that the much more devastating exposures of the Darwinian hypothesis (it is certainly no theory) by Bateson, Goldschmidt, Grasse, Broom, Punnett, Berg and Goldschmidt have also been ignored. Those reasons, exactly as Phillip Engle so clearly elucidated are purely ideological and have nothing whatsoever to do with reality.
Grasse put his finger on it with the following:
"Directed by all-powerful selection, chance becomes a sort of providence, which, under the cover of atheism, is not named but which is secretly worshipped. We believe that there is no reason for being forced to choose between "either randomness or the supernatural," a choice into which the advocates of randomness in biology strive vainly to back their opponents. It is neither randomness nor supernatural power, but laws which govern living beings; to determine those laws is the aim and goal of science, which should have the final say". page 107
"Science commits suicide when she adopts a creed"
Thomas Henry Huxley
That comment, incidentally from "Darwin's Bulldog" is the frontispiece to Leo Berg's book "Nomogenesis or Evolution Determined by Law"
Darwinism has proven to be the slowest form of ideological suicide in the history of science. I predict with some certainty that it will soon join Lamarckism as nothing but an historical footnote.
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Pim van Meurs
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Member # 541
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posted 25. April 2004 17:20
Nosivad: For all I know speciation might be going on right now but I'll bet it is not resulting from either natural or artificial selection of mutations as the Darwinian model demands.
I find it fascinating how Nosivad seems to be going from speciation has stopped to speciation may be happening but it is not related to natural selection. The goalposts are moving at a fantastic rate here.
So far Nosivad has been provided with evidence that speciation is in fact still happening and in addition the evidence suggests strongly this is due to Darwinian processes. For instance the salamander example claims that it is a classic example of Darwinian evolution.
Incipient species formation in salamanders of the Ensatina complex
So Darwinian theory seems to be doing quite well it seems.
Nosivad:
Rivista is definitely peer reviewed. I happen to know from personal experience. If you can't attack the message, attack the messenger.
What messenger am I attacking? I am trying to explain why your 'thesis' may have failed to attract much interest.
You referenced "Davison, J. 2003, "The Case for Instant Evolution", Rivista di Biologia 96:203-206" as far as I can tell this is a letter to the editor
[ 25. April 2004, 17:35: Message edited by: Pim van Meurs ]
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Argon
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Member # 276
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posted 25. April 2004 17:40
Stuart Harris writes:
"And, in the case of sexual reproduction what does it mate with?!"
One idea:
Others within its immediate group but not an outside group? I think the problem is assuming that mating compatiblity is an all or nothing proposition that arises in a single step. Instead, what if mating compatibility is a continuum where different combinations of alleles which affect compatibility exhibit different degrees of interfertility? So, in any large population, individual 'X' may be able to mate with high effectiveness with individual 'Y' but not as well with individual 'Z'. If populations split then even neutral drift could result in the loss of the 'bridging' combinations of compatible alleles between the split groups. Each group would remain interfertile by themselves but could lose compatibility between groups over time. Selection could also drive the loss of compatible alleles if hybridization between groups has negative consequences.
But let's assume that there are cases where a fertility barrier is the result of a single mutation. How would speciation arise in this particular case?
Generation 1:
Point mutation in gene 'gamma' (g) renders homozygotes incapable of breeding
with non-homozygotes (e.g. GG or Gg). An individual with a (Gg) genotype
arises.
Generation 2:
(Gg) individual mates with (GG): Produces multiple (GG) and (Gg) offspring
Generation 3+:
(Gg) offspring mate (could be from multiple generations carrying the recessive
trait) with other (Gg): Produces multiple (GG), (Gg) and (gg) offspring.
Generation 4+:
(gg) offspring available to mate with other (gg) individuals.
[ 25. April 2004, 20:27: Message edited by: Argon ]
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nosivad
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Member # 767
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posted 25. April 2004 18:53
Pim The critical word is INCIPIENT with salamander evolution. Dobzhansky used the same ploy, but later recanted. Of course my publication was a letter to the editor. My paper so inflamed one of my peer reviewers, contrary to your assertions, that, in order to get my message published, I reached an agreement with Rivista editors to publish my paper without the Conclusions section. So much for your claim that Rivista is not peer reviewed. When you have to resort to your current tactics rather than address substantive issues, there is something wrong. This is exactly the sort of thing that led to the moderater closing my "Is Evolution Thread". In that case you misrepresented me by taking a statement out of context. You also created the complete illusion that Schindewolf was not a saltationist by quoting something Stephen Jay Gould had to say about Schindewolf. I remind you that after describing Schindewolf as the greatest paleontologist of his day, Gould found it becessary to characterize Schindewolf's antiDarwinian views as "spectacularly flawed". This incredible statement was made in the Foreward to the English translation of Schindewolf's "Basic Questions in Paleontology". I regard your posture as one of simple obstruction. My publications speak for themselves and until they are acknowledged in hard copy I stand by them without reservation. As for Gould, his opus magnus, "The Structure of Evolutionary Theory", is a monument to the refusal of the Darwinians to even acknowledge, let alone respond to, the many scholars who have exposed the complete failure of the Darwinian hypothesis. It is a scientific scandal of unprecedented dimensions. To continue to suport such a failed hypothesis is, in my opinion, inexcusable. It must be, as Engle indicated, purely ideological. I can conceive of no other explanation.
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RBH
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Member # 380
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posted 25. April 2004 19:43
Stuart Harris wrote quote:
Perhaps determining an estimate of the number of species that have ever existed would help. I've seen varying estimates, some going into the hundreds of trillions as being the amount of species that have come and gone over the history of evolution. Assuming a constant rate of speciation events, wouldn't we expect to be seeing at least thousands of new ones each year? Assumimg it's not constant and the biotic world is currently in a period of stasis, then in eras when active speciation is occuring there must be millions of speciation events per year.
If one is to make estimates like this, it's necessary to look at the composition of the biosphere to figure out where one would expect to "see" speciation events, just what one would actually expect to "see," and how many one would expect to "see." First, though, I'd sure like to see some references. I have never seen an estimate of the total number of species that have ever existed that is in the hundreds of trillions. Estimates for the number of species currently on earth range in the tens of millions, of which something like 1.5 million (plus or minus a few hundred thousand, depending on who you read) are classified. The highest estimate of the total number of species over all geological time that I've seen is 4 trillion. And those estimates are pure horseback guesses - the historical data over 3.5+ billion years is simply not able to support them.
Now, by far the largest proportion of existing species are unicellular organisms, and an even greater proportion of all historical species are unicellular - the first 2 billion years or more of life on earth was unicellular. Metazooans account for only a small fraction of the total number of species. There are currently around 250,000 or so classified plant species, 50,000 or so classified vertebrate species, and maybe 1.25mm classified insect species. The remainder are mostly unicellular, though a lot of metazooa are still to be studied well enough to even classify. So something like 70% to perhaps 95% or more of all species are unicellular, where speciation events are unlikely to be obvious to the unaided eye. The proportion is even higher in the case of historical species, most of which were soft-bodied before the Cambrian and left few or no fossils. And speciation "events" sure won't be seen in species that aren't even discovered and classified yet.
Going back to the estimates, assuming a constant rate of speciation, if a total of 4 trillion species have existed over the last 3.5 or so million years, that implies a guesstimate of approximately 1.14mm speciation "events" per year (4 trillion over 3.5 billion). That's the high end estimate. At the lower end, assuming, say, 500mm total species, we'd guesstimate around 143,000 speciation "events" per year.
Now, given the estimates of the proportion of metazooa versus unicellular organisms, we'd expect from around 57,000 (5% metazooans) to 350,000 (30% metazooan) speciation "events" per year in multi-cellular organisms if there were 4 trillion total species, and from around 7,150 to 42,900 speciation "events" per year in multi-cellular species at the low end estimate of 500 million total historical species.
Now we have to ask what a speciation "event" is and how one would "see" it. Is it a great leap from one morphological "kind" to another distinctly different "kind" such that it's obvious to the unaided casual observer in a generation or two? Nope. On the time frame of the single- or double-digit years that a human observer can closely follow a given population, speciation is generally a relatively small shift in gene frequencies between two subpopulations that is sufficient to cause reproductive isolation. That change may not be primarily obviously morphological, particularly in the beginning stages of a speciation "event" . For example, the sympatric shift that has been occurring in Rhagoletis flies over the last hundred and fifty years or so is not (yet) primarily a large morphological change. It is a divergence in the timing of mating and reproduction between subpopulations, producing increasing reproductive isolation, that is governed by differences in the timing of flowering and fruiting of the haws and apples that are the hosts for the diverging subpopulations of Rhagoletis. There is active research on the behavioral, genetic, and environmental variables that are responsible for the increasing reproductive isolation of the subpopulations of flies over the last century-and-a-half. The recent occurrence of allopatric speciation can be inferred from good evidence as well.
Part of the difficulty in "seeing" speciation is that it is a gradual process in human time-scale terms. Species don't just "pop" into existence in one generation. A speciation "event" is akin to drawing apart two globules of water, where surface tension maintains a sort of 'bridge' between the globules that slowly thins over time and then finally barely separates; and then, if the dynamics of the fitness environment require it, the populations may diverge further. Somewhere in that continuum of separation is the fuzzy boundary between subspecies and species. One can tell that a speciation "event" occurred only in retrospect, looking back at the recent history of the two now-separate populations. When it is happening it is drawn out over years. That is, looking back one may be able to say, "Speciation has occurred over the last N years in these two populations," but it is difficult verging on impossible to say of a current "event" that "Speciation is now occurring in these two subpopulations."
Finally, if most speciation "events" are allopatric speciation in relatively small isolated subpopulations, our field biolgists who are responsible for gathering the pertinent data must find those small isolated populations and study them for decades in the hope that the fitness environment will change during those years in such a way as to induce speciation. Some do - see, for example, The Beak of the Finch. But there are precious few such studies: It's not easy getting and keeping consistent funding for a 30-year longitudinal study like that.
Now, given that on the order of maybe 5% to perhaps 25% of all species currently on earth have actually been classified (the minimum level of systematic knowledge being that a species is well-enough described to classify); and given that there is not an infinite number of field biologists, each of them following a a few populations for years and decades; and given that actually observing a speciation "event" requires detailed descriptions of the (probably isolated) subpopulation that is actually undergoing allopatric speciation at regular close time intervals over decades so one can look back at the data and say "There was a speciation "event") ; how many such "events" would we actually expect to systematically observe as they are happening? How likely is it that one of the few field biologists doing long-term studies of one or a few isolated subpopulations populations will be fortunate enough to pick a population to study for the next 30 or 40 years that is on the cusp of speciating in that period? And yet we do observe a few of them: there are well-documented instances of speciation that are observed closely enough, and with enough good historical data, to "see" it happening.
So the question is not whether many or few speciation "events" occur annually; it is whether we will be able to observe them as they occur. Will one occur in an existing population just when it is being closely followed over decades by a field biologist? Not likely. We won't actually see a lot of speciation events in progress, not on the scale of human lifetimes, even though a lot may actually be occurring. But we do see a few instances with good enough longitudinal time resolution and enough historical data to confirm that speciation was recently happening in a population, and those few fully affirm the evolutionary explanation for speciation. That some casual observer looking out at his back yard doesn't see new species of birds or bugs popping into view is both meaningless and deceptive. It is diagnostic of a view that hasn't been thought through carefully.
RBH
[ 25. April 2004, 20:18: Message edited by: RBH ]
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nosivad
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posted 25. April 2004 23:07
The period of great fecundity is over: present biological evolution appears as a weakened process, declining or nearing its end. Aren't we witnessing the remains of an immense phenomenon close to extinction? Aren't the small variations which are being recorded everywhere the tail end, the last oscillations of the evolutionary movement? Aren't out plants, our animals lacking some mechanisms which were present in the early flora and fauna?
The above paragraph is from page 71 of Grasse's book "Evolution of Living Organisms"
I have answered yes to each of Grasse's three questions and, having done so, then proposed an alternative to the Darwinian hypothesis. That hypothesis remains not only untested but unreferenced. It may even be true, as Schindewolf has insisted, that evolution is not an experimental science. One thing is certain. No one has as yet produced a new kind of living thing through the most intensive selection imaginable. Selection, when continued, invariably leads to a general loss of fitness. Natural selection has been a conservative process rather than a creative one which was perfectly obvious to Reginald Punnett, William Bateson, Leo Berg, Pierre Grasse, Richard Goldschmidt and among others myself. The simple truth is that the forces and mechanisms which produced new life forms are still unknown. To think otherwise is pure fantasy.
[ 26. April 2004, 08:10: Message edited by: nosivad ]
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Pim van Meurs
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Member # 541
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posted 25. April 2004 23:28
Nosivad: In that case you misrepresented me by taking a statement out of context. You also created the complete illusion that Schindewolf was not a saltationist by quoting something Stephen Jay Gould had to say about Schindewolf.
You still seem to not have learned from the moderator's actions in the other thread. I quoted Stephen Jay Gould's statement about Schindewolf.
Nosivad: regard your posture as one of simple obstruction
I apologize for asking you to back up your claims and for providing supporting claims on my part that contradict your claims about speciation.
Nosivad: To continue to suport such a failed hypothesis is, in my opinion, inexcusable. It must be, as Engle indicated, purely ideological. I can conceive of no other explanation.
I could, perhaps your viewpoint that the theory of evolution is flawed is erroneous in itself. So far I have seen little effort on your part to substantiate your claims with more than assertions. That, my friend, would indicate ideologicy to me. YMMV of course.
I notice that you have not really addressed my references that address your claim that no speciation is happening.
As far as the salamander, I wonder if you have read the references I provided to you.
Care to address them? Will you accept these as evidence the speciation is still happening?
Some other beautiful examples of (incipient) speciation can be found
in Freshwater Snails
Drosophila melanogaster
Tigriopus californicus
Nicaraguan crater lake cichlid fishes
Nosivad: No one has as yet produced a new kind of living thing through the most intensive selection imaginable. Selection, when continued, invariably leads to a general loss of fitness.
And yet data and reality seem to contradict these statements? Of course the vagueness of 'new kind of living thing' may offer Nosivad a way out but the idea that selection invariably leads to a loss of fitness is simply wrong. Perhaps Nosivad would care to support his claims with some data, calculations, observations?
[ 25. April 2004, 23:31: Message edited by: Pim van Meurs ]
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nosivad
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posted 26. April 2004 00:30
"So Darwinian theory seems to be doing quite well it seems." This statement by Pim I find utterly unbelievable. First there is no Darwinian theory. It is a failed hypothesis, every much a failure as Lamarckism, Phlogiston and the Ether. It was dreamed up by a couple of Victorian naturalists who happened to have shared a common reading experience with the works of Lyell and Malthus. They discovered absolutely nothing. Science is nothing but the discovery of what is there. Every attempt to experimentally test the Darwinian scheme has failed. To claim it is doing quite well is incomprehensible. I have no intention of engaging Pim any further as it is obvious to me that I am dealing with an intractable ideologue who is primarily interested in discrediting me and my many predecessors at any cost. I have asked Micah Sparacio to introduce my paper "The Case for Instant Evolution" as a thread for "brainstorms". I will be happy to defend it.
[ 26. April 2004, 00:33: Message edited by: nosivad ]
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warren_bergerson
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Member # 262
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posted 26. April 2004 10:16
OBSERVING SPECIATION
RBH provides a good summary of what I assume is the generally accepted view on “Why it is so difficult to observe, explain and demonstrate speciation?” To an outsider, the RBH explanation might be interpreted to mean “Biologists can not currently demonstrate the speciation process or mechanism in the laboratory”. The explanation might even be interpreted as meaning “Biologists do not currently know or understand the processes or mechanisms responsible for speciation, but they can offer speculation or predictions based on currently accepted hypotheses”.
My point being that there currently exists enough uncertainty with respect to the processes and mechanisms of speciation to permit or justify alternate interpretations of the data, alternate hypotheses and alternate predictions. As discussed earlier, I am suggesting that the available data with respect to speciation is compatible with hypotheses based on the concept of ‘speciation controlled by purposeful intelligence’. This type of hypothesis predicts that speciation is a choice or decision, and that speciation will occur when speciation is the intelligent choice (subject to applicable constraints) and speciation will not occur when speciation is not the intelligent choice or decision.
Purposeful intelligence hypotheses suggest/predict that speciation is the result of the interaction between two types of processes or mechanisms. The first type of process is labeled a species boundary mechanism. A species boundary mechanism is any process or mechanism that prevents (or significantly reduces the probability) the development of fertile offspring from interbreeding between two sub-groups of individuals. It seems reasonable to predict that species boundary mechanism are relatively simple and that they occur quite frequently.
The second type of process involved in speciation is labeled a stop speciation process. These more complex processes or mechanisms prevent species boundary mechanism from being implemented.
Purposeful intelligence hypotheses predict that if you look at any instance where speciation has occurred (i.e. where two sub-groups descended from common ancestors can not successfully interbreed), then it will be possible to identify a species boundary mechanism. Purposeful intelligence hypotheses further predict that in instances where speciation might have been expected to occur but did not, it will be possible to identify the existence of stop speciation processes that effectively prevented speciation.
Purposeful intelligence hypotheses do not deny the existence of physical-chemical processes responsible for events such as speciation. Purposeful intelligence hypotheses simply assert that there are so many different processes and mechanisms involved that it is not practical to use these mechanism to predict whether or not speciation will occur. It is, however, practical to predict the occurrence or non-occurrence of speciation( with a reasonable degree of accuracy) based on the whether speciation is an intelligent choice in support of the goal of survival.
Purposeful intelligence hypotheses would appear to offer reasonable explanations for a couple of common features of speciation. For example, purposeful intelligence hypotheses would suggest that speciation is difficult to observe in nature because it occurs very rapidly, and in many instances, speciation would not be directly associated with any easily observable physical changes. ( A factor which prevents the development of offspring or the development of fertile offspring from certain types of cross breeding need not be accompanied by an obvious change in physical appearance. )
Purposeful intelligence hypotheses might explain speciation clusters. Darwin’s finches and the Lake Victoria examples would appear to suggest that if the conditions for conducive to speciation are present (speciation is the intelligent choice) then speciation occurs not once but many times.
Purposeful intelligence hypotheses also suggest/predict that while selective breeding normally does not produce speciation, it might be possible to produce speciation by selecting for infertility when two sub-groups interbreed. Note that purposeful intelligence hypotheses would also predict that difficulty or complexity of artificially breeding a new species could depend on the type of stop speciation mechanisms that are present.
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RBH
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posted 26. April 2004 12:51
warren_bergerson wrote quote:
To an outsider, the RBH explanation might be interpreted to mean "Biologists can not currently demonstrate the speciation process or mechanism in the laboratory". The explanation might even be interpreted as meaning "Biologists do not currently know or understand the processes or mechanisms responsible for speciation, but they can offer speculation or predictions based on currently accepted hypotheses".
My remarks were directed at Stuart Harris's speculations about speciation rates through history and the ability to observe speciation occurring in real time in the wild. They had nothing to do with laboratory studies nor with hypothesized mechanisms. warren_bergerson's interpretation of my remarks is without basis: it is a misleading and deceptive misinterpretation. If an outsider interprets my remarks as warren_bergerson suggests, that outsider would be well served by more careful reading and by familiarizing himself with the actual discipline they're about. In fact, the modern synthesis has tested (in varying degrees) hypotheses about the mechanisms responsible for speciation, and at least some of those mechanisms can be directly studied in the laboratory. Others are primarily studied in the field because transfer to the laboratory is in practice difficult.
RBH
[ 26. April 2004, 12:54: Message edited by: RBH ]
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Rex Kerr
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posted 26. April 2004 12:53
RBH's estimates are useful, but they're off by a factor of 1000. 4 trillion species ever / 3.5 billion years = ~1200 species/year, at the high end of the estimate. This gives only 60-360 metazoans per year. If only 5-25% of (metazoan) species have been categorized, we'd have at the very best a chance to notice 12-90 species per year, and probably much less, since it can be difficult to distinguish between speciation events and simply finding a new related species that you haven't encountered before.
Also, since rates of speciation have varied throughout geologic history, we really need to distinguish between the lower rates and zero in order to conclude that speciation is not happening now.
I'm really perplexed by nosviad's continued assertion that speciation has halted when we have provided references to extremely recent specation events (thousands of years at best) along with examples of what look like incipient speciation events. It seems to me this is exactly what one would expect to find if speciation had not ceased.
I particularly agree with RBH's comment: "That some casual observer looking out at his back yard doesn't see new species of birds or bugs popping into view is both meaningless and deceptive. It is diagnostic of a view that hasn't been thought through carefully."
Grasse's questions aside, he does little better of a job in really nailing down whether speciation is ongoing or not. We haven't seen any new phyla recently--that much I will grant. Beyond that, Grasse can't support a complete cessation of speciation, nor does he carefully compare rates now to, for example, rates during the later Jurassic. Grasse's evidence is particularly unconvincing (as a demonstration of speciation stopping entirely) given the cichlids and various references that Pim has provided.
The dramatic and rapid spread of humans over the planet might provide a way to generate a differential hypothesis between Warren's model and the standard evolutionary model. The standard model might predict a reduced rate of speciation, since we've been doing a pretty good job of removing niches and decreasing biodiversity. Warren's model might predict an increased rate of speciation, as it would be intelligent for organisms to change so they could survive in a human-dominated world. And nosviad's model, of course, predicts no speciation at all.
[ 26. April 2004, 12:59: Message edited by: Rex Kerr ]
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