In a previous post here at TSZ Mark Frank asked why people doubt common descent.
A more interesting question is why did Charles Darwin doubt common descent?
Stephen Meyer has written two books which I think adequately answer both questions.
Those two books are:
In this thread I am willing to discuss either book, but I’d prefer to limit discussion to Meyer’s most recent book, Darwin’s Doubt
While Signature in the Cell concentrated on the origin of life, Darwin’s Doubt concentrates on the “Cambrian Explosion,” the sudden appearance of numerous distinct phyla and their subsequent diversification.
Neo-Darwinism offers no realistic account of origins, with the difference being that Darwinists can in the case of the origin of life assert that their theory does not apply while that excuse fails to apply to the appearance of different animals in the Cambrian and their subsequent diversification.
Just to prove I can – [Edited 09/15/2013]
Deleted from the OP – [Edited 09/201/2013] – Just to prove I can. “The arguments are the same for both:”
Yes, I’m really asking this.
Are you really asking if he is really asking this?
Your grammar is so confuses I can’t be sure what question you are asking.
The HOX gene exists in some single celled organisms. Single celled organisms don’t have body plans, but as multicellularity evolves, the gene regulates body plans. And yes, that is a new use for an old gene.
Most changes to body plan are variations in regulation, not the result of new genes. Change in body plan is relatively trivial compared to inventing a new gene.
When you perform a taxonomic classification of a life form you follow rules that make you check the different characteristics of each taxonomic group. When a characteristic is missing for one group you have to move that life form to other group and continue checking the carachteristics this new group.
If you found all the characteristic for a fish, you have a fish. If you have the carachteristics for an anphibian you have an anphibian. If the life form do not have the carachteristic nor for fish neither for anphibian you have somethign that it is nor a fish neither an anphibian. You do not have both.
But if you have the characteristics of both?
How about you list all the characteristics of fish and all the characteristics of amphibians.
then list the characteristics of Tik.
What do you make of mudskippers?
Have you ever studied taxonomy of something?
The taxonomical groups are perfetly defined. If not you can´t work. Thing in between are put apart from the group. If Titaalik have both characteristics will be a group itself but it will not be none of the others groups.
bias, then I guess the taxonomists must have made a mistake when classifying lungfish as being fish. They clearly have pulmonary circulation unlike other fish but like amphibians, they also have ciliated larvae unlike other fish but like amphibians, some are obligate airbreathers (not unlike some other fish but unlike them via their lung) but like amphibians, and they have a true lung unlike other fish but like amphibians. Where do you think lungfish should be placed when your grouping fish and amphibians?
No BK, is Lizzie that said that titaalik is fish and anphibian not me. So I´m Ok that lungfishes are fishes. I think that taxonomist have good reason to call them fishes and not anphibians. I´m sure a taxonomist never will say that lungfishes are both.
I guess if you define taxonomy so as to eliminate the possibility of evolution, you win. That settles it.
Science by dictionary.
How easy and convenient.
She would be correct.
Blas, Lizzie is correct. You are trying to assert what can exist by citing a dictionary definition. A creationist dictionary at that.
There are living creatures that share characteristics of both fish and amphibians.
Blas, if you are going to cite me, please link to where I said that. As I recall I was extremely meticulous in distinguishing between “amphibious” – meaning, can function in both water and land, and “amphibia” referring to the taxonomic class. Tiktaalik was amphibious, but not a member of the class “amphibia”. As for being a “fish”, Tiktaalik is a member of the Sarcopterygii, also known as “lobe-limbed fish”.
So are we.
In other words, tiktaalik is a lobe-limbed fish. It also amphibious. It is not a member of the class amphibia.
Human beings are also lobe-limbed fish. We are not amphibious. We are not members of the class amphibia.
But then as below the tree of anphibia there is no an anfibian, below the tree of chordata there is no a chordata, belowe the tree of annelida there is no an annelida. So your draw extending phyla to the root of the tree is wrong. And Meyer is right, you have first species and genera and then phyla.
Off course, first dutyof a skeptical is say Yes! to his leader.
Something that skeptical darwinists never do. Like Lizzie who started this pointing that Mayer didn`t know the difference between phyla and phylum, make his own definition of what Phyla is and mixed the classification of titaalik with his traits.
Only for avoid admitting SHE made a mistake.
Blas:
“So your draw extending phyla to the root of the tree is wrong. And Meyer is right, you have first species and genera and then phyla. “
You should consider the classification of the species Trichoplax adherens.
Trichoplax adherens is the only species in the genus Trichoplax.
Trichoplax is the only genus in the family Trichoplacidae.
Trichoplacidae is the only family in the order Tricoplaciformes.
Tricoplaciformes is the only order in the class Tricoplacia.
Tricoplacia is the only class in the phylum Placozoa.
Placozoa is one of two phyla in the subkingdom Parazoa (the other being Porifera)
The subkingdom Parazoa is one of two subkingdoms in the kingdom Metazoa
Trichoplax adherens is a real life example for Lizzies redrawing Meyers figure 2.11 (on the Meyers Mistake thread) – a single species can represent an entire phylum.
Maybe the species will be reclassified to be several species according to genetic data. Maybe they will then be subdivided into different families according to key characteristics that become apparent in the future; who knows.
As many have said before, our rank based classification system is a human concept to sort the data we obtained. So phyla, orders etc appear only when we apply the concept to the data. And the defining characteristics for our classification system are always under review to maintain/improve consistency.
Blas:
“But then as below the tree of anphibia there is no an anfibian, below the tree of chordata there is no a chordata, belowe the tree of annelida there is no an annelida. “
If you now ask what is below the tree of cordata, I would say it’s a multicellular heterotrophic eucaryote species.
Dennis Venema has written a very informative introduction to the topic
http://biologos.org/blog/evolution-basics-the-cambrian-diversification-part-2
So much for my two cent on the matter.
Edit:
I forgot to say “Hello Everybody” – too busy grappling with the editor.
Ok, May be the Lizzie´s draw is right for phylum with only one specie. How many of them you have? Meyer were not talking about that type of phylum, and no matter of that the concept tha you start with a species and then you have a phyla is correct. Because beloww the Phyla Placozoa, according to darwinism, you should have some species of common ancestors of Placozoa and Porifera
that were not Placozoa nor Porifera.
Christine:
As many have said before, our rank based classification system is a human concept to sort the data we obtained. So phyla, orders etc appear only when we apply the concept to the data. And the defining characteristics for our classification system are always under review to maintain/improve consistency.
Tel that to Lizzie, I tried to avoid the taxonomic discussion about what come first species or Phyla and go to the point Meyer were doing.
Christine:
Blas:
“But then as below the tree of anphibia there is no an anfibian, below the tree of chordata there is no a chordata, belowe the tree of annelida there is no an annelida. “
If you now ask what is below the tree of cordata, I would say it’s a multicellular heterotrophic eucaryote species.
Again, you have multicellular heterotrophic eucaryote species. before have cordata. Then you have species before phyla, you have diversity then disparity.
Tell Lizzie.
PS: Hello Christine!
Heya, Christine,
Thanks for the link to Dennis’ article․ I enjoyed it and then went back and read a couple of his earlier articles․
It should not be relevant – but it is – that Dennis is hosted at Biologos․ Our “adversaries” from UD, and folks like Stephen Meyer from the DI, could learn a lot about evolution (within a Bible-believing viewpoint) from Biologos․
From the link:
Here we go again. Yes calling Phylum os species is arbitrary I said that to Lizzie. So being arbitrary it is not the case to discuss if Lizzie`s concept of Phyla is rigth and Meyer`s is wrong. Move to the concept of what Meyer´is saying:
According to darwinism predict that life “describes a continuum” asis said in yur quote. Diversity preceeds disparity (is the only way to have a continuum) but we do not found that in CE.
Christine:
But not species, right? Because species are the only real entities in the hierarchy, right? So before you can have a phylum, you got to have species, right?
All of the entities in taxonomy are real (or at least, that’s the aim), it’s the ranks that we give them that are arbitrary. If humans were going about ranking groups in the Cambrian they wouldn’t hand out 36 phyla. But because the phyla we do have are defined as being all of the species that descend form a given common ancestor (that is , the real entity that is a phylum is a lineage or organisms) and the only way to get new lineages is to speciation is doesn’t make an sense to talk about the order in which species and phyla arise.
Species, genera, families and phyla arise at once. It’s only later that it becomes clear that at given species will end up being the progentor of a higher taxon. A hard concept to wrap your head around, I know, but a pretty important one if you wish to understand evolution in deep time.
Actually, if you’re going to make distinctions on that basis, then the concept of species is as arbitrary as any other taxonomic classification. Much less arbitrary is the concept of the gene pool: all those organisms that draw from an isolated pool of alleles. Although even there the boundaries are not absolute: population gene pools may well have a limited degree of genetic exchange with other gene pools from which they recently diverged, through migration and so on.
In the end, the patterns of divergence radiating from common origins that we find are real: the labels we attach to particular groups of such diverging populations are arbitrary.