CeilingCat
Posts: 2363
Joined: Dec. 2007
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Careful what you wish for. First, WD400 gives a partial answer: | Quote | 19 wd400
October 8, 2016 at 10:59 pm
Hi Brian,
The shape and length of bones are encoded in DNA… through protein coding genes (and functional RNAs) and through the regulation of gene expression. The details are pretty complex, but something like the action of FGF and WNT proteins in limb buds should give you and idea how these processes work.
Then, the tardeluge:
20 Dionisio
October 9, 2016 at 1:02 am
BrianFraser @18:
Excellent questions.
However, the answer you got @19 is incomplete at the best.
Let’s suppose you don’t know much about music. One day you listen to Beethoven’s 9th Symphony and ask how is that music produced? The answer you got @19 is analogous to saying that there is an orchestra that uses sheet music and several instruments.
That wouldn’t answer your question, would it?
You would expect a better explanation, wouldn’t you?
The sentence @19 “The details are pretty complex…” is a gross understatement.
The real thing is complex complexity on steroids. The final picture is not ready yet. Don’t let anyone fool you.
For example, check this out:
http://www.uncommondescent.com.....ent-618792/....-61....-618792
If we pay attention to details, any biology research paper we read may provoke a series of “how?” and “why?” questions.
Perhaps sometimes those fundamental questions are overlooked.
All we need is to recover the sense of wonder we had when we were children.
Keep asking questions. The more, the better.
Don’t worry if a professor from the U of T in Canada says that you don’t ask honest questions. Actually, that would be a nice compliment.
21 Origenes
October 9, 2016 at 1:33 am
Brian Faser #18,
Brian Faser: What part of DNA codes for shapes? What encodes the shape and length and location of a bone? What encodes facial features?
Doesn’t DNA code for things besides proteins?
I have asked very similar questions to Larry Moran and wd400:
If most of our genome is junk, then where is the information stored for the (adult) body plan? Where is the information stored for e.g. the brain? And where is the information stored for how to build all this?
Their answers:
Larry Moran: …. experts do not see a need to encode body plans and brain in our genome …
wd400: If it is not clear enough, there is no over-arching “plan” in the genome. There are genes, that have regulatory elements, which produce gene produces respond to environments and influence other genes and so on and so on.
Eric Anderson summarized their position as follows:
Eric Anderson: … this thread may have uncovered at least one aspect of the simplistic thinking that leads a person to believe that most DNA is junk.
After all, the thinking goes, all we need to do is specify some parts in the DNA and the machine will build itself all by chemistry. It’s easy! No plan needed. No program required. Just specify some gene products and we’re done. Everything else is probably just junk.
Amazing what chemistry can do.
– – –
A more principled problem for neo-Darwinism (and neutral theory) is that DNA is simply at the wrong level to organize things.
In his book ‘Darwin’s Doubt’, Stephen Meyer offers the following analogies:
At a construction site, builders will make use of many materials: lumber, wires, nails, drywall, piping, and windows. Yet building materials do not determine the floor plan of the house or the arrangement of houses in a neighborhood. Similarly, electronic circuits are composed of many components, such as resistors, capacitors, and transistors. But such lower-level components do not determine their own arrangement in an integrated circuit ….
In a similar way, DNA does not by itself direct how individual proteins are assembled into these larger systems or structures—cell types, tissues, organs, and body plans—during animal development.
“Detailed information at the level of the gene does not serve to explain form.” [Müller and Newman, “Origination of Organismal Form,” 8] |
There's lots more and even PaV tries his hand, but I can't inflict any more of this on an innocent world.
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