Here we go again folks with M. Denton's silly "typology" argument...
ANADI DASA to ALL, 06-09-93, re: "Does Evidence Support Des"
> In recent years, geneticists have discovered that in species of
> similar form the DNA and other proteins have similar molecular
More like recent decades. This was apparent as much as thirty
years ago or more. Also, many proteins show clearly identifiable
homology in the most widely diverse forms (like, say, bacteria,
fish and humans), not just in "species of similar form".
> So just as evolutionists have deduced ancestral relationships
> among species from similarities in physical form, some of them now
> deduce such relationships from the genetic similarities.
And the topography of the phylogenies or cladograms produced from
these two independent lines of evidence show very good general
agreement. But then this is just a coincidence, right?
> It is not, however, very surprising that similar species would
> have similar genetic materials. But the main point is that such
> similarities show nothing definite about how the organisms
> orginated and cannot be used as proof of Darwinian-style
> evolution. If an intelligent designer had produced varieties of
> organisms with certain structural similarities, we would also
> expect to see parallel molecular relationships.
Maybe, but this is -not- the pattern that we find when all the
evidence is considered.
Because rates of morphological change can vary greatly among
different lineages, and because many standard taxa are therefore
"paraphyletic" or even "polyphyletic" rather than monophyletic,
there are cases where the typology of evolutionary relationships
does not correspond well to the overall "structural similarities"
upon which conventional classifications are based. And even when
taxa are monophyletic, taxa of equal rank do not always (or even, I
would guess, usually) correspond to equivalent hierarchical levels
in terms of branching evolutionary relationships. In such cases
similarities at the molecular level stubbornly correspond to
phylogenetic relationships (specifically, the relative amount of
time since two forms last shared a common ancestor) rather than to
overall structural similarities.
For example, we have long known on the basis of comparative anatomy
and the fossil record that crocodiles are more closely related to
birds than they are to any of the other living reptiles.
Crocodilians are the last surviving archosaurs or "ruling
reptiles". Dinosaurs were also archosaurs. All archosaurs,
including the crocodiles, evolved from a group of reptiles called
As to birds, we know that they either evolved directly from
dinosaurs (currently the stronger theory), or that they evolved
more directly from the thecodonts. In either case they would share
a common ancestor with crocodiles among the thecodonts.
But if we want to find ancestors shared by crocodiles and
non-ruling reptiles (turtles, snakes, lizards) we would have to go
further back in time, probably back to the stem reptiles.
Now, if the evolutionary scheme I have described is correct, and
crocodiles and birds did share a more recent common ancestor than
crocodiles and non-ruling reptiles, then we should expect them to
be more similar at the molecular level, not withstanding that
crocodiles happened to have remained essentially reptilian whereas
birds have been extensively modified.
If your non-evolutionary scheme is correct then crocodiles should
resemble other reptiles at the molecular level more than they do
You want to take a guess as to which is the case?
Another example along this same line involves humans and apes. At
the molecular level is not possible to separate humans and apes at
all, for chimpanzees and gorillas resemble humans much more closely
at the molecular level than they do orangutans. (Indeed, it even
appears at this point that humans and chimps are more similar than
chimps and gorillas, but the differences in this case are extremely
slight and difficult to resolve conclusively.)
This result jives well with the fossil evidence since the discovery
that _Siva/Ramapithecus_ was an orangutan like form and not an
early hominid (human ancestor) as was once thought. If
Ramapithecus still stood as a hominid it would place the human /
african ape split too early to fit with the molecular data.
NOTE TO ALL:
Although I have been told that it is correct, I'm not entirely
happy with my reference to the fact that crocodiles and birds are
more similar at the molecular level than crocodiles and
lepidosaurs. This was first brought to my attention by the Texas
antievolutionists and textbook activists Mel and Norma Gabler.
With characteristic denseness and ironic ineducability, the Gablers
persist in claiming that this is evidence -against- evolution!
They also give a similar example based on the fact that horseshoe
crabs are "more similar to spiders". Ironically (in light of their
frequent complaints about poor grammar in textbooks) they don't say
"more similar" to WHAT; but I assume they mean crustacean type
crabs. This, of course, is a case just like the other. Scientists
recognized that _Limulus_ is more closely related to arachnoids
than to crustaceans long before the molecular evidence was even
available, and in this case I believe that even conventional
(non-cladistic) classifications reflect that.
Anyway, if anyone (possibly Jeff Otto) can give me some solid
references concerning the molecular similarities of
crocodiles/lepidosaurs/birds (and maybe the horseshoe
crabs/arachnoids/crustaceans as well, though I don't think its as
useful an example) I would appreciate it. I think that I will also
post this in talk.origins.
Other examples that could be used in this argument, of cases where
overall "typological" similarity differs from phylogenetic
relationships, would also be appreciated.
This line of argument occurred to me when I first read the Gablers
bit about crocodiles and birds. I think it is a useful supplement
to the more straightforward refutations of Denton's arguments about
molecular homologies, but I've never seen anyone else use it in the
various responses to Denton that I have consulted. As I am a
scientific lay person, I would thus be interested in comments from
those more knowledgeable. Thanks!
> In one of his recent books, prominent astrophysicist Sir Fred
> Hoyle reproduced a chart purporting to show evolutionary
> relationships among species based upon molecular studies. He
> observed, "One should not be deceived, however, by the elegance of
> this result into thinking that [the chart] proves the existence of
> an evolutionary tree. What it shows is that if a tree existed,
> then it was like this."
Whatever... But even Hoyle (who has some -very- strange views
about evolution) would appear to recognize -- re his comment about
the "elegance" of the result -- that evolutionary common descent
-does- explain the evidence in a detail and specific manner. I
would invite you to compare this to the arm waving nature of the
explanation (or, rather, rationalization) that you have offered
here. And in spite of its vague and general nature, it can still
only explain selective portions of the data, whereas evolution
successfully engages -all- of the data.
Your name (which I am guessing is Indian?) leads me to ask you the
following questions. I hope that I do not offend...
Sometime ago, in an echo on a different net, I was asked about
antievolutionism in other countries and cultures; and in religions
other than christianity, judaism or islam. I admitted that I
didn't know much, but since hinduism was specifically mentioned I
said I knew that hare-krishna, at least, held an antievolutionary
position, although I didn't know about mainstream hinduism.
I'm curious if you might be hindu (or even hare-krishna)? I would
also be interested to know if the book you mentioned awhile back,
which supposedly documents that anatomically modern humans existed
millions of years ago, might be written by a hindu or other
You see I collect antievolution literature and would like to expand
both my collection and knowledge of the subject beyond the
christian and biblical type that predominates in north america.
--- FMail 0.92
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