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Bat Evolution and Intelligent Design

 
 
farmerman
 
  1  
Reply Wed 4 Oct, 2006 07:29 pm
ros, hmmmm convergence, never thought much about bats at all. Thats interesting though, think about how convergent evolution can be consequential of some earth movememnt also.

Should I call the nurse to give spendi an enemoa?
0 Replies
 
Pauligirl
 
  1  
Reply Wed 4 Oct, 2006 08:45 pm
rosborne979 wrote:
Pauligirl wrote:
Rogue finger gene got bats airborne
· 11:00 13 November 2004
· Exclusive from New Scientist Print Edition.

http://www.newscientist.com/article.ns?id=dn6647

A change to a single gene allowed bats to grow wings and take to the air, a development that may explain why bats appeared so suddenly in the fossil record some 50 million years ago.

Sears found that a protein produced by BMP2 is present in the hypertrophic region of bats, but not in mice. When she applied the protein to the digits of mouse embryos growing in the lab they elongated just like bat digits.


I'm not clear on how this "long finger" gene works. Something doesn't make sense. How does the activiation of one gene cause the fingers to slowly elongate over many generations?



More details
http://scienceblogs.com/pharyngula/2006/04/how_to_make_a_bat.php
Together, our results indicate the up-regulation of the Bmp pathway as a major and fundamental (although not necessarily the only) mechanism responsible for the developmental elongation of bat forelimb digits. Based on our results, we raise the intriguing possibilit y that a similar up-regulation of the Bmp pathway had a role in the evolutionary elongation of bat forelimb digits, which is an event that was critical to the achievement of powered flight in bats. Recent studies have suggested that modifications to the cis-regulator y elements of developmental genes have central roles in the evolutionary diversifica- tion of morphology. Our evidence that Bmp2, but not Bmp4 or Bmp7, is differentially expressed in the bat wing digits is suggestive of a cis-regulatory change that affects the level, but not the temporal or spatial regulation, of Bmp2 expression. By linking a simple change in a single developmental pathway to dramatically different morphologies, we provide a potential explanation as to how bats were able to achieve powered flight soon after they diverged from other mammals nearly 65 million years ago.
0 Replies
 
rosborne979
 
  1  
Reply Wed 4 Oct, 2006 09:06 pm
Hi PauliGirl,

Thanks for the info. I'm trying to understand it, but I have more questions...


Quote:
Together, our results indicate the up-regulation of the Bmp pathway as a major and fundamental (although not necessarily the only) mechanism responsible for the developmental elongation of bat forelimb digits.


What do they mean by "up-regulation", and what is a BMP pathway?

Quote:
Our evidence that Bmp2, but not Bmp4 or Bmp7, is differentially expressed in the bat wing digits is suggestive of a cis-regulatory change that affects the level, but not the temporal or spatial regulation, of Bmp2 expression.


What do they mean by "affects the level, but not the temporal of spacial regulation"?

The bottom line is this: If each gene change only makes the digit grow a little bit, but not a lot, then another gene change will have to occur to make it grow even longer, right?

Even if evolution happens "quickly" it still doesn't happen over night. A pre-bat with normal toes is not going to give birth to a full blown bat.

Is there something about this one gene which causes each successive generation of bats to have longer and longer fingers? That can't be right. And if it were, what would cause the process to stop? Why wouldn't the fingers get too long and become unwieldy?

I had the same question back on my Sabertooth thread from so long ago (related to tooth growth), but I never followed the line of reasoning to a conclusion.

Maybe I just don't know enough about genetics to understand this.
0 Replies
 
real life
 
  1  
Reply Wed 4 Oct, 2006 11:17 pm
Perhaps you are too sensible.

Some of the 'earliest' known bat fossils are virtually indistinguishable from today's bats.

You see the obvious impossibility of bats 'evolving' so quickly with sophisticated skills like flight and echolocation, yet there they are.

There are other problems with bats.

Quote:
Taxonomists agree that bats come in two main sorts - megabats, such as the large Old World fruit bats, and microbats, the smaller, echo-locating ones................Look inside a fruit bat's brain and you find specialised visual pathways that look like a primate's, not a microbat's


from http://www.newscientist.com/article/mg13418161.900-is-it-a-bat-or-is-it-a-monkey-.html

So did both bats and other primates 'evolve' these specialized visual pathways independently of one another?

But we can have it both ways:

Quote:
Science: Did bats evolve twice in history?

* 04 June 1994
* JOHN TIMSON
* Magazine issue 1928

Do humans and the other primates share a common ancestor with the large bats called flying foxes? This controversial suggestion has been made before but until recently there was little evidence to support it. Now, however, biologists in Germany have confirmed the link using immunological methods.

The orthodox view is that bats are a distinct mammalian order, the Chiroptera, which can be divided into two suborders. The large fruit bats and flying foxes are grouped in the Megachiroptera while the others, small insect-eating bats and vampires, are placed in the Microchiroptera. Many zoologists believe that this classification reflects the evolution of all bats from a common ancestral form.

However, recent studies have suggested that the 'megabats' are in a sense 'flying primates', sharing a number of features with humans and the apes. Now Arnd Schreiber, Doris Erker and Klausdieter Bauer of the University of Heidelberg have looked at the proteins ...


from http://www.newscientist.com/article/mg14219282.700-science-did-bats-evolve-twice-in-history-.html

Of course, when you're a true believer anything is possible, so we'll postulate that not only could the visual pathways evolve twice, and the bats themselves evolve twice but also echolocation evolved twice. Why not?

Quote:


from http://www.newscientist.com/article/mg16522213.500-how-to-make-a-sound-choice----twice.html
0 Replies
 
timberlandko
 
  1  
Reply Wed 4 Oct, 2006 11:36 pm
Why does any of that present a "problem", rl?

Apart, of course, from your refusal or inability to accept the fact science 1) is dynamic and 2) not only thrives on but develops and advances through the spirited exchange and competition of ideas, as opposed to the static and self-declared unchanging mythopaeia to which you subscribe.
0 Replies
 
fresco
 
  1  
Reply Thu 5 Oct, 2006 12:14 am
Further to real life's "problem" I am wondering whether anybody here or on the ID thread has gone into the intricacies of "systems theory" ?

e.g.
http://web.cecs.pdx.edu/~mm/EncycOfEvolution.pdf

It seems to me that evolution cannot be accounted for by "simple" (linear) mechanisms alone yet on the other hand we now have achieved sufficient understanding of nonlinear "systems complexity" to restrict ID to the "layman's palliative" curriculum.

I do not know whether "bats" would provide a particularly interesting application of systems theory but it looks like no "species" can be considered without the its ecosystem in which there is a "niche" of interrelationship. In holistic terms there are no "bats" on their own, there are "bats within a system".
0 Replies
 
spendius
 
  1  
Reply Thu 5 Oct, 2006 03:42 am
fresco wrote-

Quote:
It seems to me that evolution cannot be accounted for by "simple" (linear) mechanisms alone yet on the other hand we now have achieved sufficient understanding of nonlinear "systems complexity" to restrict ID to the "layman's palliative" curriculum.


I presume there is an opposite to "layman". Expert say.

What estimate of the proportion of layman to expert would you offer? Is 99 to 1 anywhere near?

In a democracy wouldn't the 99 vote to retain their palliative and be happy to fund the 1's research for the material benefit they provide them with?

Is an attack on the 99 an attack on democracy. Some have said that I make no point. Well that has been one of my main points since this started.

Is science causing a division in the human race? What chance does the 1 have if it pushes and insults the 99 overmuch with gratuitous insults which serve only to reveal the ignorance of the insulter and his very weak expertise at the art of the insult.

How can the 99 be educated to the 1's "point of view" when each year pushes knowledge into more abstruse areas? Is the gap between the 1 and the 99 inevitably widening faster than any education of the 99 can possibly cope with in view of the obvious fact that teachers are in the 99, as are publishers and politicians, and intelligence is a given.

Is the 1 not a fixed group but varies with the area of knowledge? Is an expert on bats just as lost as a garbage collector when it comes to particle physics or etymology etc.

Is an attack on the palliative simply pretending to be within the 1 group using an exceedingly narrow area of knowledge simplistically viewed and focussed upon. Wouldn't a genuine member of the 1 stay out of public debate?

Are anti-IDers guilty of refusing to face up to these issues for self-serving reasons.


PS- There's a book review on Google Sunday Times Books of Richard Dawkins' The God Delusion. He's one of the 1 don't you know and I bet he can't even fix his own plumbing.
0 Replies
 
Francis
 
  1  
Reply Thu 5 Oct, 2006 04:00 am
Well, I'm out of the debate and I can fix my own plumbing.

Does that count? If so, in the 1 or the 99?
0 Replies
 
spendius
 
  1  
Reply Thu 5 Oct, 2006 04:04 am
fm wrote-

Quote:
Should I call the nurse to give spendi an enemoa?


What actually is your objection to my crude analysis of the status of the redundant idea "George Bush" which the quiz reflexes into objective existence as vibrations in the air. Is it a physical object within, say, the subconscious or the unconscious. Or do you think it an immaterial entity?

Those people, and there are many, who don't know the answer must not have this idea, object or not, within their mind.

To stimulate the response "George Bush" in order that it materialises in speech must be a material process as well.

I have studied our weekly pub quiz for a number of years now and there have been a few nurses taking part. Personally, I think they need the treatment you suggest but I'm not volunteering to provide it.

The pub quiz is quite a complex operation when organised by experts which it more or less is. And very revealing.
0 Replies
 
spendius
 
  1  
Reply Thu 5 Oct, 2006 04:16 am
Francis wrote-

Quote:
Well, I'm out of the debate and I can fix my own plumbing.

Does that count? If so, in the 1 or the 99?


There can be a number of reasons for being out of the debate so I'm unsure what to answer. Do you vote?
0 Replies
 
Francis
 
  1  
Reply Thu 5 Oct, 2006 05:12 am
Anytime there's a poll, yes...


(Don't forget the up right button..)
0 Replies
 
farmerman
 
  1  
Reply Thu 5 Oct, 2006 06:50 am
I knew if I opened my yap at RL's "picking the wrong" fossil with which to complain about natural selection, he would pick up the weapons of Creationism (forced ignorance and innerancy of Scripture) to just plotz on anything wed discuss.

After rl had posted his last submission he's in a bit of a dilemma


1If species with homologous structures can evolve independently of each other, doesnt the "built in genetic diversity" that could accomplish this make sense? Since we can follow the genetic code across species, how did this occur originally?

2Convergent evolution or"budding" of entire clades are evolutions tools to "make it through the winter" or"earn a better living" without going extinct. Miller's comment that evolution is just doing something different with what you have already, can be followed in genetics within the bats and within fossils and genetics in many others (Im willing to concede that bat fossils are rarae, but so are butterflies and honeybees) The main thing that , as we press the genetics backward, we converge many species on the Creataceous, why is this timeline coincidental with? The rise of angiosperms and pollinating insects (which become beefsteak for the insectivores and small tiktideans.

3The fact that fossil bats appear in the Eocene would imply, by evidence alone, that they werent around until sometime well after your "Creation Week"


4For rl and his bat phylogeny , "absence of evidence is not evidence of absence" (a phrase he uses quite frequently) but he never explains how this works so, if he would like, why not use bats as an example of Creation. Please give some time lines and some evidence that is compelling (No quotes from Genesis please)
0 Replies
 
rosborne979
 
  1  
Reply Thu 5 Oct, 2006 08:12 am
I found some of the answers to my own previous questions in the link PauliGirl provided earlier:

Quote:
One of the wonderful things about how development works is that organisms function as wholes, and changes in one property trivially induce concordant changes in other properties. Tug on one element, changing it's orientation or size, and during embryogenesis any adjacent elements make compensatory adjustments, so that the resultant form flows, fits, and looks organic. This isn't that surprising a feature of development, though, unless you have the mistaken idea that the genome encodes a blueprint of morphology. It doesn't; what it contains is a description of interacting agents that work together in a process to produce a complex result. Changes in genes and regulatory elements can essentially produce changes in rules of development, rather than crudely specifying blocks of morphology.

What does this mean for evolution? It means that subtle changes to the rules of development can be caused by small changes to genes (and especially, to regulatory regions of genes), and that the resulting morphological changes may be dramatic, but are still integrated organically into the form of the organism as a whole. Our understanding of how development works is making it clear that large scale macroevolutionary change may be much easier than we had thought.


One part I have to give more thought to is this: "This isn't that surprising a feature of development, though, unless you have the mistaken idea that the genome encodes a blueprint of morphology. It doesn't; what it contains is a description of interacting agents that work together in a process to produce a complex result."

I'm beginning to see how large scale changes can occur more easily if genes don't control morphology directly, but instead, control growth/development.
0 Replies
 
rosborne979
 
  1  
Reply Thu 5 Oct, 2006 08:18 am
real life wrote:
You see the obvious impossibility of bats 'evolving' so quickly with sophisticated skills like flight and echolocation, yet there they are.


What we have to understand here is what people mean when they say "so quickly". Nobody that understands evolution is suggesting that a bat popped out of a mouse, no matter how quickly they say things happened. When someone says "quickly" to me, I still think of geologic timeframes where hundreds of thousdands to millions of years is still considered "quickly".

And no RL, it's not obviously impossible. We already know that bats evolved, the questions are, through what stages, by what sequence of mechanisms and how quickly.
0 Replies
 
farmerman
 
  1  
Reply Thu 5 Oct, 2006 10:36 am
consider that humans went from ape-like beings to full H ss in about 3 million years.

Remember that, with recent understandings of extra genomic DNA and DNA in the introns, the "regulator genes" dont have to be in the coding part of the genome at all, thus giving even more possible molecular diversity than we originally thought.


Hox genes code from within and outside of the chromosomes
0 Replies
 
rosborne979
 
  1  
Reply Thu 5 Oct, 2006 02:49 pm
fresco wrote:
Further to real life's "problem" I am wondering whether anybody here or on the ID thread has gone into the intricacies of "systems theory" ?

e.g.
http://web.cecs.pdx.edu/~mm/EncycOfEvolution.pdf

It seems to me that evolution cannot be accounted for by "simple" (linear) mechanisms alone yet on the other hand we now have achieved sufficient understanding of nonlinear "systems complexity" to restrict ID to the "layman's palliative" curriculum.

I do not know whether "bats" would provide a particularly interesting application of systems theory but it looks like no "species" can be considered without the its ecosystem in which there is a "niche" of interrelationship. In holistic terms there are no "bats" on their own, there are "bats within a system".


More good points. Thanks Fresco.
0 Replies
 
spendius
 
  1  
Reply Thu 5 Oct, 2006 05:23 pm
Seems like ros is asserting that he's one of the 1 to me.
0 Replies
 
spendius
 
  1  
Reply Thu 5 Oct, 2006 05:25 pm
Stretching "1" a bit of course. Upwards.
0 Replies
 
farmerman
 
  1  
Reply Thu 5 Oct, 2006 05:54 pm
fresco
Quote:
It seems to me that evolution cannot be accounted for by "simple" (linear) mechanisms alone yet on the other hand we now have achieved sufficient understanding of nonlinear "systems complexity" to restrict ID to the "layman's palliative" curriculum.


That style of consideration is many decades OOD. Haldane and Goldschmidt were some of the last "single function neoDarwinians". Todays evolution models consider the concept of multiple cladistic s as well as the dynamics of the environment and geologic changes. As far as many of the models Ive seen (Holland et al) , Im less than impressed because they start with what we know and end not to far from there. Step function analyses from existing fossil morphologies have been most useful. Where we have a significant number of intermediates , using CGI, its possible to insert a reasonable facsimile of an "internal link".
The hardest part of anything that can make sense, is to understand the environmental changes that affect the species makeup.
Remember, the most dynamic part of evolution is the system to which the evolvees adapt. EG, so far no model (except a real w. a. g.) could have predicted the 3 fold increase in the concentration of free oxygen during the Mississippean through the mid Permian, nor could it predict the rapid deglaciation and subsequent acid deposition of the late Permian through the Triassic. What systematics could do is to provide a limited list of environmental options that each new bolide or volcano presents to the planet.
0 Replies
 
rosborne979
 
  1  
Reply Thu 5 Oct, 2006 09:43 pm
farmerman wrote:
ros, hmmmm convergence, never thought much about bats at all. Thats interesting though, think about how convergent evolution can be consequential of some earth movememnt also.


Bat evolution linked to warming

Microbat paraphyly and the convergent evolution of a key innovation in Old World ...

farmerman wrote:
Should I call the nurse to give spendi an enemoa?


I think we should go right to the labotomy.
0 Replies
 
 

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