The gaps keep getting smaller and smaller

| 124 Comments

As we all know, Tiktaalik roseae is a magnificent example of a transitional fossil connecting aquatic critters–fish–with tetrapods, 4-limbed critters. Nevertheless, there are still gaps in that transitional sequence. A recent PNAS paper (link to abstract; full paper is behind a paywall) describes fossils of early amphibians that are later than Tiktaalik and are within Romer’s Gap. Romer’s Gap is a period around 15 million years long, from roughly 360mya to 345mya, where (up to now) there was a distinct lack of fossils of proto-tetrapods or related critters. The new PNAS paper’s senior author is Jenny Clack, one of the most prominent paleontologists studying that era, (along with people like Neal Shubin and Per Ahlberg. Per was an active commenter on the late lamented Internet Infidels Discussion Board way back when I was an administrator of IIDB.

With these new fossils, the transition from water to land animals is becoming nearly as well documented as the synapsid to mammal transition. Nobel Intent has more on the new paper.

124 Comments

No, the gaps are getting more numerous.

I’m not sure if you actually read the paper. It describes finds from Scotland that fill in gap in the timeframe of the fossil record, not a physiological gap in the transition from fish to tetrapods. The “proto-tetrapods” are proper amphibians and not some monstrous intermediate kind.

Atheistoclast said:

I’m not sure if you actually read the paper. It describes finds from Scotland that fill in gap in the timeframe of the fossil record, not a physiological gap in the transition from fish to tetrapods. The “proto-tetrapods” are proper amphibians and not some monstrous intermediate kind.

The “gap” referred to is Romer’s Gap, which is, as I plainly indicated, a temporal gap, even giving the years for it.

Who suggested they were some “monstrous intermediate kind”, assuming that in contrast to most creationists, you can provide an operational definition of “kind”? Transitional sequences are composed of instances from very early (say, Eusthenopteron) through “monstrous” intermediates like Tiktaalik to amphibians in the right time frame 25-30 million years later. The PNAS paper describes the latter.

And, as I’ve noted, Atheistoclast gets one comment per thread of mine; that was it.

Per still comments regularly here:

http://talkrational.org/forumdisplay.php?f=23

Although he hasn’t actually talked about this latest paper.

Richard B. Hoppe said:

Atheistoclast said:

I’m not sure if you actually read the paper. It describes finds from Scotland that fill in gap in the timeframe of the fossil record, not a physiological gap in the transition from fish to tetrapods. The “proto-tetrapods” are proper amphibians and not some monstrous intermediate kind.

The “gap” referred to is Romer’s Gap, which is, as I plainly indicated, a temporal gap, even giving the years for it.

Who suggested they were some “monstrous intermediate kind”, assuming that in contrast to most creationists, you can provide an operational definition of “kind”? Transitional sequences are composed of instances from very early (say, Eusthenopteron) through “monstrous” intermediates like Tiktaalik to amphibians in the right time frame 25-30 million years later. The PNAS paper describes the latter.

And, as I’ve noted, Atheistoclast gets one comment per thread of mine; that was it.

Sorry, but you asked me a non-rhetorical question so I have a right to a reply:

The translation of the Latin word, genus means “kind”. In fact, they both come from the same Proto-Indo-European root. Can you provide an operational definition for the term, genus?

Atheistoclast said: The translation of the Latin word, genus means “kind”. In fact, they both come from the same Proto-Indo-European root. Can you provide an operational definition for the term, genus?

Well, it’s more than just “kind” as in Noah’s Ark:

Origin: Latin: race, stock, kind, gender - biology: any of the taxonomic groups into which a family is divided and which contains one or more species. For example, Vulpes (foxes) is a genus of the dog family ( Canidae ) - from dictionary.com

The term comes from Latin genus “descent, family, type, gender”, cognate with Greek: γένος – genos, “race, stock, kin”. … In the hierarchy of the binomial classification system, genus comes above species and below family. - from wikipedia.com

So if genus = kind, how many genera were on Noah’s Ark? (I’ve worried for years how many wood-eating beetles were on Noah’s Ark, not to mention beavers and termites and carpenter bees.)

Paul Burnett said:

So if genus = kind, how many genera were on Noah’s Ark? (I’ve worried for years how many wood-eating beetles were on Noah’s Ark, not to mention beavers and termites and carpenter bees.)

What about wood rot? There’s numerous genera of wood rot.

Reed,

You’re both right. The gaps are getting more numerous and smaller.

All that is shown by these fossils is diversity of creatures. Here and always the fossil record is not biological evidence based on biological investigation using the scientific method. casts of creatures should not be important or needed in a biological subject.

if the only way or a needed way is to see geological sequence between these fossil types to determine evolutionary relationship then its not about biological research of the casts but geological facts. Its been the great flaw of evolutionary biology to draw its confidence from evidence that is not from biological investigation. One can not do biology on rocks.

theres plenty of room to see these fossils as unrelated simply having bits and pieces perfectly suited to them in a more diverse past.

No, Byers. What it shows is that animals with a mosaic of fish-like and amphibian-like basal features once existed, but not modern salamanders, frogs and newts. These animals existed in the specific window of time in which the paleontological evidence says that amphibians were separating from fish. That separation is confirmed by these fossils, as predicted and explained by evolution. Creation, which says merely that all animals were created at the same time, does not predict this, and explains none of it.

Geology and paleontology support each other, Byers, just as any reasonable person would expect, seeing as they both partake of objective fact. Nonsensical blather about how the one can’t be used to support the other is simply idiotic.

Both Byers and Atheisto@$$hole are displaying their profound arrogance and ignorance on a galactic scale. Evolution explains perfectly the specific forms of these fossils and their locations in a way Creationism cannot. Indeed, if Creationism were valid, those fossils should never have been found at all.

Indeed, why would a Creator even bother with amphibians, you morons?

Let me preface this with the note that I am not a scientist, so I welcome corrections.

As far as I can tell, genus is defined as a convenient fairly small collection of species.

There is no objective definition of “genus” which applies uniformly across the world of life. There is little in common between genera of plants, of fungi, of insects, of molluscs, of vertebrates, etc. There is no sharp dividing line between species which are in one genus and those in another. The same is true of other taxonomic ranks like family, order, class, subfamily, subgenus, tribe. The only rank which has a more or less objective definition is species.

This is a result of the evolution of species.

RBH, I just looked at Clack’s website. For those who don’t know, Per Ahlberg was her first Ph. D. student. He’s now a professor of evolutionary organismal biology at the University of Uppsala.

As for Romer’s Gap, Clack collaborated with her former postdoc Michael Coates (now a colleague of Shubin’s at Chicago) on this symposium paper:

Coates, M. I. and Clack, J. A. 1995 Romer’s Gap - tetrapod origins and terrestriality. In Arsenault, M. Lelièvre and Janvier P. (Eds) Proceedings of the 7th International Symposium on Lower Vertebrates, Miguasha: Studies on Early Vertebrates. Bulletin de la Muséum national de l’Histoire naturelle, Paris. 17, 373-388.

As soon as I heard about Shubin’s (Technically Shubin et al.) discovery of Tiktaalik, I was quite optimistic that we’d see eventually the entire transition from lobe-finned fishes to early tetrapods; Clack and her colleagues are demonstrating that quite convincingly.

TomS said:

As far as I can tell, genus is defined as a convenient fairly small collection of species.

As a former paleobiologist, TomS, I am in complete agreement with regards to your understanding of higher taxonomic levels (above the species level). However, I believe that there are some genera that have scores of species, not just one or a few.

There is no objective definition of “genus” which applies uniformly across the world of life. There is little in common between genera of plants, of fungi, of insects, of molluscs, of vertebrates, etc. There is no sharp dividing line between species which are in one genus and those in another. The same is true of other taxonomic ranks like family, order, class, subfamily, subgenus, tribe. The only rank which has a more or less objective definition is species.

This is basically correct, particularly since the same nomenclature is used for bacteria and archae.

It doesn’t mean that these concepts are meaningless. The reflect a nested hierarchy of life. A nested hierarchy without clear boundaries is what the theory of evolution predicts.

As another non-scientist, with respect to methods of classification, identification of relatedness between species, clades, or whatever: Isn’t it a fact that as far as everything we have discovered and learned about biology and the history of life on this planet, supported by facts and evidence from so many facets of science over 150 years, that life on earth is one great continuum, with everything related to everything else?

No evidence, nothing points to ‘special creation’ of even the most basic piece of biology. Even the most virulent of pathogens are the inevitable result of evolution, and not what according to creationist thinking would have to be God’s own unique creation.

If God created them, we are commiting a great sin by fighting them. Leave HIV, Ebola, Malaria, Borelia, TBE or TBC alone to do what the Lord put them here for. Even with the mutations they are picking up all the time to make them even more sinister.

As another non-scientist, with respect to methods of classification, identification of relatedness between species, clades, or whatever: Isn’t it a fact that as far as everything we have discovered and learned about biology and the history of life on this planet, supported by facts and evidence from so many facets of science over 150 years, that life on earth is one great continuum, with everything related to everything else?

Yes, but it is also a nested hierarchy. All types of life seem to have common ancestry, but some have more recent common ancestry than others.

No evidence, nothing points to ‘special creation’ of even the most basic piece of biology. Even the most virulent of pathogens are the inevitable result of evolution, and not what according to creationist thinking would have to be God’s own unique creation.

Yes.

As a completely non-religious person, I still feel compelled to point out that only hard core creationists, not religious people in general, insist on special creation of pathogens. Also, many hard core creationists deny that microbes cause disease and insist that disease is caused by demons or is a magical punishment for sin.

Also, there are many equally virulent pathogens of non-human life, that have no impact on humans, despite being virulent pathogens for something else.

If God created them, we are commiting a great sin by fighting them. Leave HIV, Ebola, Malaria, Borelia, TBE or TBC alone to do what the Lord put them here for. Even with the mutations they are picking up all the time to make them even more sinister.

Again, even as a completely non-religious person, I feel compelled to point out that most religious people do NOT endorse this view.

“Disease is God’s will and we should not resist it” has occasionally been advocated, even including by some theologians who were not “Biblical literalists”.

However, even if we assume the existence of the Christian God (not my personal belief), that is merely an assertion.

If we grant the existence of God, it is theoretically possible that God created pathogens to punish us and is angered when we fight them, or that God created pathogens so that we would be challenged to fight them, or that God set off the big bang or life on earth to see what would happen and pathogens happened to evolve, etc.

dalehusband said:

Indeed, why would a Creator even bother with amphibians, you morons?

Then what would God have used to plague the Egyptians with? Junkfood and Amway salesmen?

dalehusband said:

Indeed, why would a Creator even bother with amphibians, you morons?

But surely the amphibians would have a different take on all this, wondering why a creator would bother with additional animals once the paragon of creatures had already emerged. Anyhow, there’s an old bit from Sir Thomas Browne about how man is the true amphibian capable of inhabiting both the material and the spiritual realms. So lets show a little respect for the amphibians.

TomS said: There is no objective definition of “genus” which applies uniformly across the world of life. There is little in common between genera of plants, of fungi, of insects, of molluscs, of vertebrates, etc. There is no sharp dividing line between species which are in one genus and those in another. The same is true of other taxonomic ranks like family, order, class, subfamily, subgenus, tribe. The only rank which has a more or less objective definition is species.

And there is no objective definition of “kind” either. So, please, give up on this pretense that the taxonomy proposed by the creationists is any less rigorous than that proposed by the evolutionists. Moreover, the word “kind” is used to describe certain types of enzyme or transposon.

Atheistoclast said:

And there is no objective definition of “kind” either. So, please, give up on this pretense that the taxonomy proposed by the creationists is any less rigorous than that proposed by the evolutionists.

Ah, but “kinds” are supposed, by creationists, to be absolutely rigorous! Each was created in a separate act, and they share no common ancestry. There is an absolutely rigorous barrier between “kinds” such that it is and always has been impossible for one “kind”, say artiodactyls, to evolve into another “kind”, such as cetaceans.

The strange thing is, with these absolute biological barriers, creationists are unable to show any convincing mechanism that could halt the evolution of species within a “kind” and prevent them from becoming other “kinds”. They can’t even identify taxonomically where the barriers are.

So although the definition of “kinds”, supposedly being based on an absolutely rigorous biological phenomenon, should be easy, creationists can’t seem to manage it.

Just Bob said: Ah, but “kinds” are supposed, by creationists, to be absolutely rigorous! Each was created in a separate act, and they share no common ancestry. There is an absolutely rigorous barrier between “kinds” such that it is and always has been impossible for one “kind”, say artiodactyls, to evolve into another “kind”, such as cetaceans.

Well, let’s look at the artiodactyls. They are not really a “kind” - they are just a loose grouping of mammals sharing a particular feature. Giraffes and hippopotami are both artiodactyls and yet their morphology and physiology couldn’t be any more different except for having an even number of toes. Indeed, the artiodactyl “order” breaks down nicely into separate “infraorders” and “families” which I would regard as being the real “kinds”.

The strange thing is, with these absolute biological barriers, creationists are unable to show any convincing mechanism that could halt the evolution of species within a “kind” and prevent them from becoming other “kinds”. They can’t even identify taxonomically where the barriers are.

Natural selection is that mechanism. It keeps things as they are.

So although the definition of “kinds”, supposedly being based on an absolutely rigorous biological phenomenon, should be easy, creationists can’t seem to manage it.

Animals from different “kinds” cannot interbreed with one another. Animals of the same “kind” should be able to (though perhaps not leaving fertile offspring). Hence, zebras and horses are the same kind but not pigs and cows.

Eventually there will be an infinite number of infinitessimally small gaps.

Atheistoclast said:

Just Bob said: Ah, but “kinds” are supposed, by creationists, to be absolutely rigorous! Each was created in a separate act, and they share no common ancestry. There is an absolutely rigorous barrier between “kinds” such that it is and always has been impossible for one “kind”, say artiodactyls, to evolve into another “kind”, such as cetaceans.

Well, let’s look at the artiodactyls. They are not really a “kind” - they are just a loose grouping of mammals sharing a particular feature. Giraffes and hippopotami are both artiodactyls and yet their morphology and physiology couldn’t be any more different except for having an even number of toes. Indeed, the artiodactyl “order” breaks down nicely into separate “infraorders” and “families” which I would regard as being the real “kinds”.

The strange thing is, with these absolute biological barriers, creationists are unable to show any convincing mechanism that could halt the evolution of species within a “kind” and prevent them from becoming other “kinds”. They can’t even identify taxonomically where the barriers are.

Natural selection is that mechanism. It keeps things as they are.

So although the definition of “kinds”, supposedly being based on an absolutely rigorous biological phenomenon, should be easy, creationists can’t seem to manage it.

Animals from different “kinds” cannot interbreed with one another. Animals of the same “kind” should be able to (though perhaps not leaving fertile offspring). Hence, zebras and horses are the same kind but not pigs and cows.

You had your one post and your reply on this thread already. Soon you will be unceremoniously dumped to the bathroom wall and once again segregated from decent society. In anticipation of this glorious event, you can find my response to this nonsense there already.

Grrr. Take an evening and day off and it goes to Hell. I’ll leave what’s there, but that’s it for Atheistoclas.

Eventually there will be an infinite number of infinitesimally small gaps.

There might be a hole in that theory!

Natural selection is that mechanism. It keeps things as they are.

I recently learned something that got stuck in my mind. It was about dog evolution. There are so many breeds of dogs, with widely differing characteristics. The short legged dogs are special because it seems they share a common ancestor, a single mutation responsible for that characteristic.

I presume that is a case of artificial selection, not natural selection. But that is just a matter of circumstance. I don’t see any reason why a mutation with such obvious impact might not become fixed if favoured by environmental factors.

I understand that work is under way to determine if a similar condition in humans is caused by a similar mutation as well.

I would change the “keeps things as they are” to “may keeps things that are of value whether they are ancient or brand new”.

Rolf said:

Natural selection is that mechanism. It keeps things as they are.

I recently learned something that got stuck in my mind. It was about dog evolution. There are so many breeds of dogs, with widely differing characteristics. The short legged dogs are special because it seems they share a common ancestor, a single mutation responsible for that characteristic.

I presume that is a case of artificial selection, not natural selection. But that is just a matter of circumstance. I don’t see any reason why a mutation with such obvious impact might not become fixed if favoured by environmental factors.

I understand that work is under way to determine if a similar condition in humans is caused by a similar mutation as well.

I would change the “keeps things as they are” to “may keeps things that are of value whether they are ancient or brand new”.

Absolutely. Natural selection only “keeps things as they are” if the environment does not change. If the environment does change, given enough genetic variation, natural selection can cause relatively rapid changes in just about any character. JOe plays the creationist shell game and conveniently forgets about the environment and genetic variation. He just mischaracterizes natural selection as operating alone in a constant environment. Either he does not know any better, or he choose to misrepresent deliberately. Either way, he’s just plain wrong.

By the way, NOVA recently had a special on dog evolution. They showed how comparative genomics is being used to search for diseases that are predisposed by mutations in humans by looking at susceptible dog breeds. The program illustrates how important the story of dog evolution is and how we are learning more about it every day. It also illustrates the power of new comparative genomics approaches to the study of evolution. It is a great example of how evolutionary theory is used in medicine, something that creationists are fond of denying for some reason. I highly recommend the show. Perhaps someone would want to devote a thread to the topic. Maybe then Joe could describe to us how natural selection prevented any changes in the dog lineage.

Rolf said: The short legged dogs are special because it seems they share a common ancestor, a single mutation responsible for that characteristic.

Not exactly - it’s artificially selected / reinforced achondroplastic dwarfism - see http://en.wikipedia.org/wiki/Achond[…]ther_species

The point has been made several times, but perhaps bears repeating: there is no essential difference between artificial and natural selection. Objectively speaking, the breeder is just part of the dog’s environment. Anyhow, people are not the only organisms whose activities change the adaptive landscape for other organisms. Coevolution of predators and prey and parasites and hosts provide plenty of examples, not to mention sexual selection, a mechanism that produces outcomes just as artificial looking as bull dogs.

Robert Byers said:

There are not evidence of processes.

I don’t know why I bother, but… We have found dinosaur trackways, including tracks of predators apparently following herbivores. Why isn’t that evidence of the simple biological PROCESS of walking, and hunting? We have found dinosaurs of the same species in various stages of life, from still in the egg, through newborn, youth and fully mature. Why isn’t that evidence of the biological PROCESSES of birth, growth, and aging? Do we have to observe a human through his whole life to study those things, or can we study the “biological processes” by observing different individuals at various life stages?

DS said:

Evolutionism sometimes presents fossils as more then second fiddle sometimes not but even second fiddle can be very important. if your agreeing that fossils are evidence for evolution BY biological investigation then we can agree.

Biological processes conclusions are in the main the result of biological investigation. Fossils or address are this and even genetics.

How can you stand to do that (write like Byers)? You have a stronger constitution than I do, muchacho.

Just Bob said:

Robert Byers said:

There are not evidence of processes.

I don’t know why I bother, but… We have found dinosaur trackways, including tracks of predators apparently following herbivores. Why isn’t that evidence of the simple biological PROCESS of walking, and hunting? We have found dinosaurs of the same species in various stages of life, from still in the egg, through newborn, youth and fully mature. Why isn’t that evidence of the biological PROCESSES of birth, growth, and aging? Do we have to observe a human through his whole life to study those things, or can we study the “biological processes” by observing different individuals at various life stages?

Fossils aren’t evidence of biological processes because Robert Byers says so. Nevermind that he’s too cowardly to explain why, other than that he says so.

Of course, Robert Byers refuses to explain why Young Earth Creationism is supposed to be a superior explanation, as, apparently it’s “off thread.”

Though, if trying to explain why Young Earth Creationism is off-topic, then Robert Byers shouldn’t be saying anything to begin with, and his constant mention of him being a Young Earth Creationist is pointless hypocrisy.

Evolutionism presents fossils as more then second fiddle unless second fiddle is very important.

Well, look up for yourself in any intro Biology 101 textbook that Darwin and Wallace used evidence other than fossils.

On second thought, it’s doubtful you’ll do it.

But anyone else can look it up for him/herself.

Even if there were no fossils, even if there were no remains left of extinct species, comparative anatomy of living species alone would support evolution. So would using bio-geography on living (again, living) species.

if your agreeing that fossils ain’t evidence for evolution BY biological investigation then we can agree.

There are indeed no fossils used directly within evo-devo, bio-geography and many other biology sub-fields! Yet, evo-devo gives great support for evolution.

On the other hand, click here for an introduction to paleobiology. Fossils are merely preserved examples of once-living (and thus biological) matter.

You didn’t even touch the question of why YECs/”Flood geologists” with advanced training in geology/paleontology are virtually nonexistent. Seems there’s also little hope of you ever publicly rebutting in detail the Glover and Morton material based here on your past comments.

Byers, are you really not from the hollers of east Tennessee?! Perhaps you grew up in French-speaking Canada with English being merely your second language?

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