Mr Jack
New member
Once again, bob, what level are you calling a 'major group'?
Lack of transitional fossils: another evolutionary dilemma?
- Thread starter bob b
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Cmon, bob. Don't embarass yourself further. You played the quote game, and you lost. Arguing that species are "major groups" is clearly not honest. Gould says without qualification that transitionals are abundant above the species level. Precisely the opposite of what you claimed he said.
So, now that it's clear that the experts don't agree with your claim, how about putting it to a test. Let's define what a "transitional" would be, and see if we can find any.
Or you can cut and run again.
Rock and a hard place, um, bob?
So, now that it's clear that the experts don't agree with your claim, how about putting it to a test. Let's define what a "transitional" would be, and see if we can find any.
Or you can cut and run again.
Rock and a hard place, um, bob?
Skeptic
New member
A point against "multiple types of fairly advanced creatures at the beginning"? -- Absence of empirical evidence.
Does THIS list answer some of your questions regarding transitionals, Bob?
Decades ago, many scientists expected to find more transitionals than they found back then. .... Bob, in general, do most of today's scientists think they have found as many transitionals as they realistically expect to find at this point, given geological factors, the rarity of fossilization and other factors?
Do today's scientists expect the fossil record to be a comprehensive record of all life that has existed?
Do today's scientists expect to find finely detailed sequences of fossils lasting for millions of years?
Do today's scientists expect that even most of the organisms that have lived will be represented in the fossil record? .... Or do they now think that only those rare individuals that lived in favored environments and possessing hard parts are likely to have been preserved in the fossil record?
If bob would like to see species-to-species transition for tens of millions of years, I can show him one of those.
Apparently, he is still not willing to test his assertion with real evidence. If you ever do get up the gumption to do that, bob, let me know. I'll show you some transitionals.
Apparently, he is still not willing to test his assertion with real evidence. If you ever do get up the gumption to do that, bob, let me know. I'll show you some transitionals.
Andre1983
New member
Once again, I sense a misuse of the term "transitional".
Every mutation in every surviving and mating individual in a population contribute to this "transitional" form.
Heck -- There is likely to be no transitional form; only forms that are either noticably different, and thus another """transitional"""*** is required -- or unnoticably different which means that another """transitional"""*** is required.
Funny thing is, if all we had were """transitional"""*** forms -- the creationist would complain about us not having the "transitional" forms; namely the forms we have today.
A--ab--B--bc--C--cd
If we now have form A, B and C -- and the modern form of this branch of species is D -- creationists want to see "ab", "bc" and "cd".
If they were to see those forms, they would realize that something is still missing...
C1--cx--cd--cy--D
Where is cy?
If they were shown cy -- they would realize something was missing...
cd--c1--cy--c2--D
Where is C2?
If they were shown C2 ... They would see that something was missing...
C2--C3--D
Where is C3?...
They won't be happy untill we find a species that have salted and mummified their ancestors and have keept them all frozen for millions of years...
*** (As in the forms that are between the fossils of an evolved species-- not as in suddenly warped forms; evolution is gradual not sudden changes...)
Every mutation in every surviving and mating individual in a population contribute to this "transitional" form.
Heck -- There is likely to be no transitional form; only forms that are either noticably different, and thus another """transitional"""*** is required -- or unnoticably different which means that another """transitional"""*** is required.
Funny thing is, if all we had were """transitional"""*** forms -- the creationist would complain about us not having the "transitional" forms; namely the forms we have today.
A--ab--B--bc--C--cd
If we now have form A, B and C -- and the modern form of this branch of species is D -- creationists want to see "ab", "bc" and "cd".
If they were to see those forms, they would realize that something is still missing...
C1--cx--cd--cy--D
Where is cy?
If they were shown cy -- they would realize something was missing...
cd--c1--cy--c2--D
Where is C2?
If they were shown C2 ... They would see that something was missing...
C2--C3--D
Where is C3?...
They won't be happy untill we find a species that have salted and mummified their ancestors and have keept them all frozen for millions of years...
*** (As in the forms that are between the fossils of an evolved species-- not as in suddenly warped forms; evolution is gradual not sudden changes...)
Yep. The infamous "Gish Gallop", named after the ICR creationist who invented the scam.
b_baggins
New member
Millions. Billions. If you logically think through the consequences of the theory: gradual changes over long periods of time, the obvious conclusion is that the dominant fossil would be the transition fossil. In fact, finding a uniquely identifiable species would be a rarity, an event worthy of headlines.
The very fact that we observe distinct species discredits the theory of gradual change over time. If that were really happening, we'd see a continuous smear of life from single-celled organisms all the way to man.
But, that never bothers evolutionists, who proudly proclaim any observation a validation of the theory no matter how contradictory. So even though logically thinking through the theory's assumptions produces NO species, the direct observation in opposition to that is hailed as proof of the theory.
Go figure.
b_baggins
New member
Wrong analogy. A bullet firing from a gun is a one-time event. Evolution is a steady-state, continual process. The better comparison is a day at Disneyworld, where I CAN take a snapshot and observe every stage of a human being's life cycle at a given moment. We shouldn't even HAVE to examine the fossil record. We should be able to examine the current biosphere and see transitional forms all over the place. We should be seeing species changing into other species, especially among bacteria which can produce thousands of generations in short periods of time. We should be seeing prokaryotic bacteria evolving into eukaryotic bacteria over and over and over again, since the mutation mechanisms and selection pressures that created the first ones still exist today.
The criticisms Darwin faced from naturalists in his day still stand today. The CURRENT biosphere does not support Darwin's hypothesis of speciation through gradual change and natural selection.
Skeptic
New member
Creationists don't.
We do. ... Most, however, have become extinct.
We do.
See:
Observed Instances of Speciation
Some More Observed Speciation Events
New Species
We have. See above.
What makes you think that the same selection pressures still exist today? .... Today's dense presence of multiple microscopic life forms changes the playing field considerably, don't you think?
Today's scientists do not think that evolution was totally gradual.
Science evolves. .... Perhaps it's time for creationists to do the same.
SUTG
New member
I don't think you're doing too good a job of 'logically thinking through the conesquences of the theory'. The fossil record and current biological observations look just as if they should if evolution were accurate.
Mr Jack
New member
Tell me, what features would let us identify a living animal as a transitional form?
The first known life dates to roughly 2 billion years before the first known eukaryotic bacteria. Given the length of time it took to occur the first time around why should we expect it to occur suddenly this time round? Further, the selection pressures are most categorically not the same - for a start the niches are far from open - they're now filed with highly evolved eukaryotes.
All fossils ever found are of transitional forms. All organisms that have ever existed on earth are transitional forms. Most organisms don't fossilize, however, which is why the fossils we do find are so different from one another.
If every organism were fossilized, then yes, we would see an un-broken line. However, that's just not how it works.
b_baggins
New member
No, we don't. Show me a single organism with a mixture between two other species such that we can claim a true transition is taking place. A good example would be a lizard with feathers. It had to happen at some point. Or a bird that walks on all fours but with wing-like front legs. It had to happen at some point. Show me something like this in the biosphere today, and you'll have an argument to make that Darwinian evolution is occurring.
b_baggins
New member
Making declarative statements does not make them true.
If evolution occurs by continual gradual change, please explain why there are discreet species? Continual gradual change means you would see a fossil history like the following:
Dinosaur.
Dinosaur with feathers
Dinosaur with feathers and beak.
Dinosaur with feathers, beak and wings.
Dinosaur with feathers, beak, wings and hollow bones.
Dinosaur with feathers, beak, wings, hollow bones and flight keel, and maybe it's not a dinosaur anymore, we really can't tell at this point. It's something else, not a bird, not a dinosaur, a dinobird.
The point being that there is no distinct line between the two types of creatures. At some arbitrary point it's so much like a bird and so little like a dinosaur, you start calling it a bird, but, like the Beard fallacy, it's kind of hard to actually draw the line.
There is NOTHING like that in the fossil record or the current biosphere. On the contrary. The exact opposite is true. Organisms are very clearly delineated into categories. The best you can come up with is that monkeys all look similar to one another and to people, so you conclude that monkeys became people. It's a classic post hoc fallacy.
And this IS understood among some evolutionary biologists which is why punctuated equilibrium and the hopeful monster theories keep getting recycled.
b_baggins
New member
Yeah, I hear this a lot. It's bunk. That's like saying horses and dogs are transitional forms to something else. A transitional fossil would be a dinosaur that was so much like a bird you couldn't really place it as a bird or a dinosaur; it would have an equal mixture of both characteristics.
You have just engaged in a tautology, or proving something is true by saying that it is true.
The fact is, we have millions and millions of fossils. Fossils are so common you can buy them by the gross for 50 cents a piece. To sit here and claim that the best you can come up with are some mere superficial resemblances (well, this anthropoid's skull shows some similarities to that anthropoid's skull so they are in an evolutionary chain) but can't produce a single dinosaur with feathers despite hundreds of thousands of dinosaur and bird fossils, tells just how unsupportive the fossil record is. Just among the millions of trilobite fossils we have, you should find at least ONE that is part trilobite and part something else. After all, it had to happen at some point. At SOME point if dinosaurs evolved into birds, you have to have a dinosaur with feathers.
Again, this is not unique to creationists. Evolutionary biologists who support punctuated equilibrium and hopeful monster theories understand the fossil record does not have sufficient quantities or types of transitional forms to support gradual change from one species to another.
But, again, we shouldn't even have to look at the fossil record. Bacteria are still evolving, and the same mutations and selection pressures that created nuclei in bacteria before are still in effect. Go find us a bacteria with a partial nucleus. Or, better yet, evolve one in the laboratory. You claim to know the mechanism, and it is 100% reproducible in the lab, so go evolve some nucleus-bearing bacteria from bacteria that don't have any. We'll wait.
b_baggins
New member
Making declarative statements does not make them true.
If evolution occurs by continual gradual change, please explain why there are discreet species? Continual gradual change means you would see a fossil history like the following:
Dinosaur.
Dinosaur with feathers
Dinosaur with feathers and beak.
Dinosaur with feathers, beak and wings.
Dinosaur with feathers, beak, wings and hollow bones.
Dinosaur with feathers, beak, wings, hollow bones and flight keel, and maybe it's not a dinosaur anymore, we really can't tell at this point. It's something else, not a bird, not a dinosaur, a dinobird.
The point being that there is no distinct line between the two types of creatures. At some arbitrary point it's so much like a bird and so little like a dinosaur, you start calling it a bird, but, like the Beard fallacy, it's kind of hard to actually draw the line.
There is NOTHING like that in the fossil record or the current biosphere. On the contrary. The exact opposite is true. Organisms are very clearly delineated into categories. The best you can come up with is that monkeys all look similar to one another and to people, so you conclude that monkeys became people. It's a classic post hoc fallacy.
b_baggins
New member
Yes. It's the only living member of the family and genus left, but the fossil record shows other species in the same genus and family, so yes, the Platypus can be clearly categorized. 100 years ago, you might have an argument. But like pretty much everything in evolutionary biology, the more you learn, the less evidence there is to support it.
It is an interesting animal because it has a bill, and it lays eggs, though the bill is nothing like a bird's bill, and the eggs are more reptilian than avian.
But, it turns out to be its own kind of mammal and not some mash up between a mammal and a bird and a reptile.
Anyway, all of this is moot to me. I'm old school when it comes to science: I want to see the lab work. Probably the result of my Chem professors drilling that into my head. No lab work, automatic F. Re-create an evolutionary pathway in the laboratory and you can persuade me. Work with bacteria; they breed quickly. Evolve me a eukaryotic bacteria from a prokaryotic bacteria. Irradiate some cultures and start applying selection pressures. Until then, it's all just story telling.
But that's not going to happen. Instead I'll now hear from a bunch of people claiming I'm scientifically ignorant, or don't understand evolution, or am stupid, or will link junk science links from Talk Origins. Meanwhile people will continue to argue back and forth about the fossil record and no one will actually perform the above experiment. Welcome back to the days of Aristotle.
Disruptive selection. A good example in progress right now, is the disruptive selection of the hawthorn maggot fly/apple maggot fly. After the introduction of apple trees into North America, the hawthorne maggot fly began to parasitize apples (which are related to hawthorns). But because the fruiting of each is timed differently, selection tended to favor one form that conformed to the hawthorn and one that conformed to the apple.
And now, they don't interbreed. Possibly, they can't interbreed in nature. They are on the cusp of speciation. And no intermediates exist now.
Herrerasaurus, a good prototypical dino
Beaks came first, possibly long before feathers. Think of triceratops, and many others.
Whoops. You jumped a step or two First came dinosaurs with feathers, beaks, and protowings. We have examples of those, too. And the small dromeosaurs had hollow bones before protowings. Ornitholestes, for example.
And beaks came rather late, although they had been present in many dinosaurs from time to time. Archaeopteryx, for example, has the skeleton of a dinosaur with the jaws of a dinosaur, but has wings and could fly. But it might be an offshoot. Dromeosaurs had beaks.
Archaeopteryx lacked a keel, flattened ribs, pygostyle, and many other bird features, but most people now consider it a primitive bird.
Archy is pretty close, um?
You've been badly misled on that. For example, go though the anatomical features of Archaeopteryx and explain why it's clearly a bird, or clearly a dinosaur.
You honestly believe that? No wonder you hate science. You don't know what it is. BTW, monkeys are too evolved in their own way to have evolved into apes, much less people.
Would you like to learn about the evidence for the evolution of primates?
It's noteworthy that fossil platypuses have teeth, and are more generalized than the highly specialized modern animal. Just one more bit of evidence for evolution. Oh, and developing embryos get teeth, although they lose them before they mature.
Which is pretty much what you'd expect from a transitional between reptiles and mammals. It also has a reptilian cloaca, and the complex reptilian shoulder bones.
It has no birdlike features, of course. But it does have a lot of reptilian ones.
In biology, that's not enough. You also have to do field work. For example, the examination of dinosaurs and birds in the lab by Huxley enabled him to predict the existence of intermediates, since the evidence showed birds evolved from dinosaurs. He never found them, but we have quite a few now. His hypothesis, based on evidence he found in his anatomical studies, was verified by investigation which turned up the predicted fossils. This is the way science works.
Even chemists have to do field work, sometimes. But biology is a more demanding discipline.
Better yet, evidence directly from nature is available. But we have a good deal of labwork showing how evolution works. For example, the evolution of prokaryotes has a huge body of experimental data to support it. Would you like to learn about some of it?
As you probably heard, the key element in the evolution of prokaryotic is the acquisition of organelles like mitochondria. They have their own, bacterial DNA, and replicate apart from the rest of the cell. The evidence is that they are the result of endosymbiosis, bacteria that were ingested or invaded the cell, and became mutually interdependent. Is there experimental data for this? Turns out that there is:
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/E/Endosymbiosis.html
But has anyone actually observed bacteria becoming endosymbionts? Turn out that they have:
Temperature Sensitivity: A Cell Character Determined by Obligate Endosymbionts in Amoebas
K. W. JEON 1 and T. I. AHN 1
1 Department of Zoology, University of Tennessee, Knoxville 37916
A strain of Amoeba proteus has lost its ability to survive at temperatures above 26°C as a result of becoming dependent on endosymbiotic bacteria that are psychrophile-like. The observed temperature sensitivity develops in fewer than 200 host cell generations (18 months of culture) after the host cells are experimentally infected with the symbionts.
Surprise. :shocked:
Biologically ignorant, maybe. But you seem to have a rather limited idea of the way scientists gather evidence.
Most people don't understand evolution. I've spent a lifetime learning about it, and I'm far from understanding all of it.
Talk.origins does link to some creationist sites, but they also link to many respected sources, like Nature.
Surprise again. You see, sometimes it's not even necessary to do an experiment. Just go out and take a look. If the data confirm the hypothesis, then you have verification.