Quest For the Unbroken Chain
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Related
thread, Transitional
Forms.
Scott Wed 11/13/2013 9:52 AM: Good morning! :^)
Please see last three paragraphs.
Scott Thursday, October 10, 2013 11:39 PM: It appears you want to see
a complete and unbroken chain of transitional forms with no gaps ad infinitim before you would concede that humans evolved
from simpler species.
Casey:
I’m not demanding such a perfectly unbroken chain. Rather, I’m looking for any
transitional forms whatsoever. Instead, we see paleoanthropologists admitting
that we haven’t found transitions between humanlike creatures and apelike
creatures in the fossil record. For example, a study of the pelvic bones
of australopithecines and Homo proposed “a period of very rapid evolution
corresponding to the emergence of the genus Homo.”[1] In
fact, a paper in the Journal of Molecular Biology and Evolution found that Homo
and Australopithecus differ significantly in brain size, dental function,
increased cranial buttressing, expanded body height, visual, and respiratory
changes and stated: ‘We, like many others, interpret the anatomical evidence to
show that early H. sapiens was significantly and dramatically different from...
australopithecines in virtually every element of its skeleton and every remnant
of its behavior.”[2]
Scott Wednesday, November 13, 2013 6:52 AM:
I don’t have the context of this article. So, it’s impossible for me to
understand the point that is being made. Such descriptions are subjective. What
does it really mean to say “differ significantly” or “significantly and
dramatically”? If you compare a Homo to a jelly fish, now you have a
significant difference. And in light of that difference, the Homo and the
Australopithecine would appear almost as first cousins.
Casey Wed 12/4/2013 11:35 PM:
Thanks for
your note today which reminded me that you had sent a couple e-mails that I’d
forgotten to respond to Here are my responses:
Sure, Homo
and Australopithecus are much more similar than Homo and cnidarians (jelly
fish). But that doesn’t mean that Homo and Australopithecus are similar.
The terms
“differ significantly” and “significantly and dramatically” are not
“subjective” words, and they aren’t even my words. They come from a paper by
some leading paleoanthropologists in the journal Molecular Biology &
Evolution. Specifically, that paper wrote:
“the earliest H. sapiens remains differ significantly
from australopithecines in both size and anatomical details.” (emphasis added)
“We, like
many others, interpret the anatomical evidence to show that early H. sapiens was
significantly and dramatically different from earlier and penecontemporary australopithecines in virtually every
element of its skeleton (fig. 1) and every remnant of its behavior.” (emphasis added)
And what are
those differences? Well, according to this paper, it includes “size,”
“anatomical details,” “anatomical evidence,” as well as “virtually every
element of its skeleton” and “every remnant of its behavior.” That’s a lot of
differences. You can read the paper (attached) if you want to know more
details.
The point is
this: Every species has similarities and differences from others, and some
species are more similar than others. But the myth that’s “out there” is that
australopithecines were like little miniature humans with a chimp-like head,
and that’s simply not true. There were many important differences between
australopithecines and humans.
Scott
1/30/14: This means absolutely nothing. According to John Searle, all mammals are most certainly
conscious because they all have the same mental apparatus and fish are probably
conscious, but he doesn’t want to think about it too hard because he’s trying
to hold off becoming a vegetarian. If from a consciousness perspective, a mouse
is similar to a man, most certainly, Australopithecines
are similar to Homo Sapiens. Elsewhere, we are told that a Banana has 50% of
its DNA in common with humans. If the DNA of a banana is similar to humans, again
most certainly, Australopithecines are
similar to Homo Sapiens.
Whenever we can find DNA, we can show proximity to Homo Sapiens
with Hemoglobin-B studies. As Chimp DNA is very similar to Human DNA, again
most certainly, Australopithecines are
similar to Homo Sapiens.
So Casey, you have failed here to
provide any interesting information. Really, showing “significant difference”
is completely arbitrary. So, what are you trying to achieve? Are you just
playing out the clock?
So let’s just make this plain.
There is a common species between the human and the chimp, CHLCA. This common species is likely much
closer to a chimp than to a human. It is most certain that the Australopithecines
are an excellent transitional form between the CHLCA and Homo
Sapiens because they have some of the
features of each species. Further, Homo
Habilis appears to be more advanced than
Australopithecines and less advanced than Homo
Erectus.
Scott 3/24/14: Perhaps a nice
little walk down hominid lane can help.
Here’s a description of the CHLCA. And here’s a description
of the Australophithecines. Maybe you can
do your own comparison.
Here’s a very nice description of
Homo/Australopithecus habilis.
Here’s the wiki
on Homo Erectus.
On pp. 16, there’s a table
containing advancements of Homo over the Australopithecines.
Here’s a nice comparison of Homo Erectus
and Homo Habilis. By Suzanne Kemmer.
Her interest is in language. However, she also covers other facets of behavior.
Here’s a nice little analysis
based on 2008 entries in Wikipedia.
http://www.diffen.com/difference/Homo_Habilis_vs_Homo_Sapiens
Homo
Sapiens means, “wise man”, ha ha ha.
It seems everyone is getting into
the discussion. Here are a couple things on Yahoo Answers:
Difference between Homo Erectus
and Homo Sapien.
Obviously, anything on Yahoo
Answers is going to be questionable. As an example, this writer claims Homo Erectus had fire. In contrast, Suzanne Kemmer
was much more conservative and informative regarding Erectus’ use of fire.
Difference between Homo Erectus
and Homo Sapien skull.
This one is probably describing
something anyone else could describe by just looking JPEGs of the two skulls.
It’s a pretty lame comparison,
admittedly. Nevertheless, each and every claim can be evaluated.
My point is that there appears to
be a clear progression over these species. They clearly progress in function
over time. Therefore, all these specimens are transitional forms. And, as
Dawkins points out in his TGSOE,
we are going to see difficulty classifying individuals as we see more and more
specimens. There will necessarily be specimens straddling the mid-point between
those that we have found in the past.
Scott 1/30/14: In your link
admonishing Eugenie Scott for suggesting the misleading aspect of the term
“missing link”, you missed her point.
The truth is, every
newly discovered fossil of a creature we didn't know of before IS a missing
link. There is no need to hype a story unnecessarily.
This point is echoed throughout
Dawkins, TGSOE. So it’s
clear, you will never accept a transitional form, nor can you. It would
devastate ID.
Scott Wednesday, November 13, 2013 6:52 AM :
How do the creationists define “transitional form”? How will they ever know if
they truly see one?
Casey Wed 12/4/2013 11:35 PM: I’m not sure how
creationists would define a transitional form, but I can tell you how I’d
define one: A fossil that’s found stratigraphically
between species A, and species B, and shares morphology that is intermediate
between species A and species B, especially in relation to key features that
define species B.
By that very
reasonable definition, transitional forms are almost non-existent.
The reality,
however, is that the phrase "transitional form" is often used in two
different ways. The "soft" definition of "transitional"
implies that an organism merely needs to bear features that are representative
of a potential intermediate -- even if the fossil itself was not a direct
transitional form.
Under the
hard definition of "transitional form," a stronger claim is made that
this organism actually was a real-life lineal intermediate between two taxa, a
direct transitional form. As evidence that this soft/hard distinction is used,
for example, when some early tetrapod tracks were first reported in early 2010,
Nature's Editor's Summary said: "The finds suggests that the elpistostegids that we know were late-surviving relics
rather than direct transitional forms, and they highlight just how little we
know of the earliest history of land vertebrates" (emphasis added). The
qualified term "direct transitional form" is a nod to the writer's
understanding that there is in fact a "hard" definition of a
transitional form, and a "soft" definition, and that some fossils
don't meet the hard definition. What some people call a "transitional
form" isn't necessarily a "direct transitional form."
I use the
“hard” definition of a transitional form, which means that the organism you’ve
found actually WAS A TRANSITIONAL FORM. Seems quite
reasonable to me.
Scott 1/30/14:
Remember, above you said,
I’m not demanding such a perfectly unbroken
chain. Rather, I’m looking for any transitional forms whatsoever.
So here it
is. Let A = CHLCA, B = Homo Sapiens. In this case, Australopithecines satisfy your
criteria for a transitional form. How directly they are to the exact path of
decent is an interesting question. Are they “over easy” or “over hard”? I don’t
know. My guess is they are “over medium”. How do you like that?
In any case,
as a transitional species, they severely damage the plausibility of ID… unless
you can prove your deity just brought them into existence in the blink of an
eye. Maybe you could look for burn marks from Intelligent Agents as they left
earth with their space ship after creating Australopithecines. Or maybe you can
find it in some obscure passage in the bible.
Scott Wednesday, November 13, 2013 6:52 AM :
I could say that the fish is a transitional form. It is transitional between
the single celled animal and the Homo Sapien.
Who could say that I am wrong and what would their reasoning be?
Casey Wed 12/4/2013 11:35 PM: Exactly. And some
Darwinists would say exactly what you’re saying! One Nature blogger
wrote: “The truth is, every newly discovered fossil of
a creature we didn't know of before IS a missing link.” (http://blogs.nature.com/houseofwisdom/2011/06/what_not_to_do_when_discussing.html)
So here’s
what’s going on:
If you define
"transitional form" in a soft enough way, so that neither temporal
placement nor phylogenetic relationship matters any more, then it becomes very
difficult to disprove claims that a fossil was "transitional." It's a
wily rhetorical tactic, designed to make Darwin-skeptics look ignorant while
simultaneously taking the focus off the lack of actual (e.g. hard) transitional
forms in the fossil record. Some people complain that ID proponents define such
forms "in such a way that none could ever be found," when in reality
it's Darwinian evolutionists who define transitional fossils so loosely that
they must, by definition, be found in abundance--even if they weren't
necessarily part of an evolutionary transition. Thus we see the Nature blogger
quoted above saying absurd things like "every newly discovered fossil of a
creature we didn't know of before IS a missing link."
But none of
this changes the fact that leading scientists have admitted a LACK of
transitional forms documenting the evolution of humans:
A 1998
article in Science noted that at about 2 mya,
“cranial capacity in Homo began a dramatic trajectory” that resulted in
an “approximate doubling in brain size.”[1] Wood and Collard’s review in Science
the following year found that only one single trait of one individual hominin fossil species qualified as “intermediate”
between Australopithecus and Homo: the brain size of Homo
erectus.[2] However, even this one intermediate trait does not
necessarily offer any evidence that Homo evolved from less intelligent
hominids. As they explain: “Relative brain size does not group the fossil hominins in the same way as the other variables. This
pattern suggests that the link between relative brain size and adaptive zone is
a complex one.”[3]
Likewise,
others have shown that intelligence is determined largely by internal brain
organization, and is far more complex than the sole variable of brain size. As
one paper in the International Journal of Primatology writes, “brain
size may be secondary to the selective advantages of allometric
reorganization within the brain.”[4] Thus, finding a few skulls of intermediate
size does little to bolster the case that humans evolved from more primitive
ancestors.
Similar to
brain size, a study of the pelvic bones of australopithecines and Homo
proposed “a period of very rapid evolution corresponding to the emergence of
the genus Homo.”[5] In fact, a paper in the Journal of Molecular
Biology and Evolution found that Homo and Australopithecus
differ significantly in brain size, dental function, increased cranial
buttressing, expanded body height, visual, and respiratory changes and stated:
“We, like many others, interpret the anatomical evidence to show that early H.
sapiens was significantly and dramatically different from… australopithecines
in virtually every element of its skeleton and every remnant of its
behavior.”[6]
Noting these
many changes, the study called the origin of humans, “a real acceleration of
evolutionary change from the more slowly changing pace of australopithecine
evolution” and stated that such a transformation would have included radical
changes: “The anatomy of the earliest H. sapiens sample indicates
significant modifications of the ancestral genome and is not simply an
extension of evolutionary trends in an earlier australopithecine lineage
throughout the Pliocene. In fact, its combination of features never appears
earlier.”[7]
Scott
5/22/14: See Step Functions in the Record. Also, see Cherry Picking
for discussion on misleading use of quotations from scientists.
These rapid,
unique, and genetically significant changes are termed “a genetic revolution”
where “no australopithecine species is obviously
transitional.”[8] For those not constrained by an evolutionary paradigm, what
is also not obvious is that this transition took place at all. The lack of
fossil evidence for this hypothesized transition is confirmed by Harvard
paleoanthropologists Daniel E. Lieberman, David R. Pilbeam,
and Richard W. Wrangham, who provide a stark analysis
of the lack of evidence for a transition from Australopithecus to Homo:
“Of the
various transitions that occurred during human evolution, the transition from Australopithecus
to Homo was undoubtedly one of the most critical in its magnitude and
consequences. As with many key evolutionary events, there is both good and bad
news. First, the bad news is that many details of this transition are obscure
because of the paucity of the fossil and archaeological records.”[9]
As for the
“good news,” they still admit: “[A]lthough we lack
many details about exactly how, when, and where the transition occurred from Australopithecus
to Homo, we have sufficient data from before and after the transition to
make some inferences about the overall nature of key changes that did
occur.”[10]
In other
words, the fossil record provides ape-like australopithecines, and human-like Homo,
but not fossils documenting a transition between them.
In the
absence of fossil evidence, evolutionary claims about the transition to Homo
are said to be mere “inferences” made by studying the non-transitional fossils
we do have, and then assuming that a transition must have occurred somehow,
sometime, and someplace.
Again, this
does not make for a compelling evolutionary account of human origins. Ian Tattersal also acknowledges the lack of evidence for a
transition to humans:
“Our
biological history has been one of sporadic events rather than gradual accretions.
Over the past five million years, new hominid species have regularly emerged,
competed, coexisted, colonized new environments and succeeded—or failed. We
have only the dimmest of perceptions of how this dramatic history of innovation
and interaction unfolded…”[11]
Likewise,
evolutionary biologist Ernst Mayr recognized our
abrupt appearance when he wrote in 2004:
“The
earliest fossils of Homo, Homo rudolfensis
and Homo erectus, are separated from Australopithecus by a large,
unbridged gap. How can we explain this seeming saltation? Not having any
fossils that can serve as missing links, we have to fall back on the
time-honored method of historical science, the construction of a historical
narrative.”[12]
As another
commentator proposed, the evidence implies a “big bang theory” of the
appearance of our genus Homo.[13]
Scott
1/31/14: Casey, I think you’re sending some redundant material here.
So
what I’m asking for isn’t a perfect unbroken chain of transitional forms, just
some good evidence that a transition took place. Unfortunately, that’s not what
I find.
I think I’m
justified in being skeptical that there are transitional forms between the
apelike australopithecines and humans. Thanks.
Scott 3/24/14:
Additional information is provided above. Also, see Homo Habilis.
Casey
Scott
3/23/14: Please reference Transitional Forms.
[1] Dean
Falk, “Hominid Brain Evolution: Looks Can Be Deceiving,” Science, 280
(June 12, 1998): 1714 (diagram description omitted).
[2]
Specifically, Homo erectus is said to have intermediate brain size, and Homo
ergaster has a Homo-like postcranial
skeleton with a smaller more australopithecine-like brain size.
[3] Wood and
Collard, “The Human Genus,” 65-71.
[4] Terrance
W. Deacon, “Problems of Ontogeny and Phylogeny in Brain-Size Evolution,” International
Journal of Primatology, 11 (1990): 237-82. See also Terrence W.
Deacon, “What makes the human brain different?,” Annual
Review of Anthropology, 26 (1997): 337-57; Stephen Molnar, Human
Variation: Races, Types, and Ethnic Groups, 5th ed. (Upper
Saddle River: Prentice Hall, 2002), 189 (“The size of the brain is but one of the
factors related to human intelligence”).
[5] Marchal,
“A New Morphometric Analysis of the Hominid Pelvic Bone,” 347-65.
[6] Hawks, Hunley, Lee, and Wolpoff,
“Population Bottlenecks and Pleistocene Human Evolution,” 2-22.
[7] Ibid.
[8] Ibid.
[9] Lieberman,
Pilbeam, and Wrangham, “The
Transition from Australopithecus to Homo,” 1.
[10] Ibid.
[11] Ian
Tattersall, “Once we were not alone,” Scientific American (January,
2000): 55-62.
[12] Ernst Mayr, What Makes Biology Unique?:
Considerations on the Autonomy of a Scientific Discipline (Cambridge:
Cambridge University Press, 2004), 198.
[13] “New
study suggests big bang theory of human evolution” University of Michigan News
Service (January 10, 2000), accessed March 4, 2012, http://www.umich.edu/~newsinfo/Releases/2000/Jan00/r011000b.html
Scott Thursday, October 10, 2013 11:39 PM: “And even if this is
achieved (which almost certainly we could always be looking for finer and finer
transitions), it appears that you would argue that these transitions would
simply be design re-use. I’m not sure that hypothesis, which seems to be
implicit in your writings, is falsifiable.”
Casey:
An evolutionary transition is different from arguing that two species share
similar traits. For example, humans have two eyes and fruit flies have two
eyes. Although humans and fruit flies are said to share a common ancestor,
nobody is going to say that they have the types of similarities which show an evolutionary
transition. So an evolutionary transition requires a lot more than mere shared
similarity. It has to show one form gradually morphing into another. That’s
what I’m talking about.
Related
thread, Transitional
Forms.
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