Gene Involved in Brain Development Evolved Rapidly in Humans

[TeddyKGB]

http://www.livescience.com/humanbiology/060816_har1_gene.html

It is, perhaps unsurprisingly, an RNA regulatory gene.

Mark Kennedy, the ball is firmly in your court.

 

[NASAg03]

I was about to post a similar article posted on the Houston Chronicle online.

Current research holds that humans and chimps split on the evolutionary tree about 7 million years ago. In identifying a section of DNA that has changed more than 70 times as rapidly as the rest of the human genome, researchers may have found out how, though not why, that split came about.

...

Like the other scientists, Rogers was impressed by the scale of the evolution of the HAR1 gene when the odds were so seemingly stacked against it.
"A change like what they found?" Rogers said. "It's way, way out there on the probability curve."
The surprising find is unlikely to sway those who dispute the idea that humans and apes share a common ancestor. Surveys regularly show 40 percent of Americans don't accept the theory of evolution.
"The authors note that the evolutionary changes in question happened rapidly, and they can, apparently, document some of the necessary changes," said mathematician and philosopher William Dembski, a former faculty member at Baylor University and an advocate for intelligent design.
"But that hardly explains what caused the changes and how they were coordinated to bring about our more complex and developed brains."

http://www.chron.com/disp/story.mpl/metropolitan/4122722.html

Not only has new, more complex information been added to the DNA, but it has happened 70 times more quickly than other changes. I don't see how this supports evolution at all.

This means the "common ancestor" of the chimp and human had to have a number of specific, complex, benficial mutations to it's DNA which we're just cut-n-paste errors, or deletions, but actually ADDED information, and did so 70 times quicker than expected, as a result of ERRORS.

 

[TeddyKGB]

Not only has new, more complex information been added to the DNA, but it has happened 70 times more quickly than other changes. I don't see how this supports evolution at all.

Be serious now; common descent was hardly in jeopardy over questions surrounding human brain development.

Unless you have evidence to support the contentions 1) that complex information can't be added to DNA; and 2) that the mutation rate compared to "other changes" is physically impossible (or even exceedingly unlikely), your argument remains one from incredulity. As usual.

This means the "common ancestor" of the chimp and human had to have a number of specific, complex, benficial mutations to it's DNA which we're just cut-n-paste errors, or deletions, but actually ADDED information, and did so 70 times quicker than expected, as a result of ERRORS.

ZOMG!1! If only a maverick naturalist could have envisioned a mechanism for preserving beneficial changes. And if only he could have published a book about it in, say, November 1859.

 

[sfs]

Not only has new, more complex information been added to the DNA, but it has happened 70 times more quickly than other changes. I don't see how this supports evolution at all.

This means the "common ancestor" of the chimp and human had to have a number of specific, complex, benficial mutations to it's DNA which we're just cut-n-paste errors, or deletions, but actually ADDED information, and did so 70 times quicker than expected, as a result of ERRORS.

I'm afraid your response doesn't make a lot of sense to me. Why do you call this "new, more complex information"? The changes are simple substitutions of one nucleotide for another. What's more complex about replacing an A by a T, or a G by an A, something that happens randomly all the time? In your version of genetics, does DNA become even more complex if the T is later replaced by an A again, and you end up with the identical sequence you started with?

I also don't see why this would be difficult to accomplish with random mutations. Over the last seven million years, every nucleotide in the region (as with any region in the genome) has mutated a couple of hundred times in one of our ancestors. The raw material for selection, the "ERRORS" must have happened, so why shouldn't they have been selected for?

 

[USincognito]

I wonder if part of the problem Creationists have with even properly addressing brain growth from the time of our chimp/human LCA until modern homos is their time dialete view of the world history. They seem to think that we were chimps and then suddenly are fully modern technological humans within a few dozen or hundred generations. Even if the genetic changes were rapid, we're still talking aobut on an evolutionary time scale and seven million years passing from the LCA to us today.

 

[Carey]

http://www.livescience.com/humanbiology/060816_har1_gene.html

It is, perhaps unsurprisingly, an RNA regulatory gene.

Mark Kennedy, the ball is firmly in your court.

See proof of evolution post.

 

[Baggins]

See proof of evolution post.

why? you provide no evidence to back your claims up, they are just rhetoric

 

[NASAg03]

I'm afraid your response doesn't make a lot of sense to me. Why do you call this "new, more complex information"? The changes are simple substitutions of one nucleotide for another. What's more complex about replacing an A by a T, or a G by an A, something that happens randomly all the time? In your version of genetics, does DNA become even more complex if the T is later replaced by an A again, and you end up with the identical sequence you started with?

I also don't see why this would be difficult to accomplish with random mutations. Over the last seven million years, every nucleotide in the region (as with any region in the genome) has mutated a couple of hundred times in one of our ancestors. The raw material for selection, the "ERRORS" must have happened, so why shouldn't they have been selected for?

You're simplifying the information. We both know that beneficial features of an organism takes more than just a few letter changes. You can't improve a computer program by changing a few 0's to 1's. It takes a number of changes to make the program comparatively better (for a specified purpose), and those changes have to be coordinated and organized.

I have no problem believing that information in a peice of DNA can be erroneously copied, and through additional errors than peice of data is changed. Still, you have one set of information that is either copied or changed, but no new information added to the system, with information being organized data that carries a purpose or message.

a few changes in A's, G's, and T's doesn't add new features or make any large changes to an organism. We are too complex for that. It takes larger-scale mutations to make significant, advantagous changes. Those mutations either copy existing information, change peiced of existing information, or delete information. Organized, new information doesn't just get mutated into an organism, and small information changes of DNA letters aren't enough to give an organism enough of a competitive advantage to be naturally selected.

irratiated flys grow extra EXISTING body parts, or loose EXISTING body parts. Bateria become resistent to antibiotics because they LOOSE information in the DNA.

 

[rmwilliamsll]

Bateria become resistent to antibiotics because they LOOSE information in the DNA.


not necessarily, the topic of the biochemistry of antibiotic resistance is a good example of the TofE.

see:
http://www.science-projects.com/AntibioticStrat.htm

an introductory article on the topic.
there are several ways of antibiotic resistance that include making brand new enzymes to damage or destroy the antibiotic. This is accomplished by modifying existing proteins to do the new task, in an environment where this mutation will be strongly selected for.

if you are interested you can see:
http://www.genomenewsnetwork.org/articles/05_00/antibiotic_resistance.shtml

where the anti-anti-antibiotic therapy is discussed in specific terms that help understanding of the importance of the TofE in the science of antibiotic resistance.

 

[TeddyKGB]

I have no problem believing that information in a peice of DNA can be erroneously copied, and through additional errors than peice of data is changed. Still, you have one set of information that is either copied or changed, but no new information added to the system, with information being organized data that carries a purpose or message.

"Purpose" and "message" are loaded, metaphysical terms when used a priori. They have no place in a scientific discussion.

a few changes in A's, G's, and T's doesn't add new features or make any large changes to an organism. We are too complex for that.

Not a problem since evolution does not predict large changes in a single organism.

It takes larger-scale mutations to make significant, advantagous changes.

Or an amassing of smaller-scale mutations.

Those mutations either copy existing information, change peiced of existing information, or delete information. Organized, new information doesn't just get mutated into an organism, and small information changes of DNA letters aren't enough to give an organism enough of a competitive advantage to be naturally selected.

You are in full propaganda-mode. You picked up on a term - information - and creationist misrepresentations thereof, without a real clue what it means in a biological context.

irratiated flys grow extra EXISTING body parts, or loose EXISTING body parts.

Good thing. Evolution would go haywire if individual flies could change into rats.

Bateria become resistent to antibiotics because they LOOSE information in the DNA.

What about nylon-eating bacteria?

 

[sfs]

You're simplifying the information. We both know that beneficial features of an organism takes more than just a few letter changes.

No, I'm not simplifying the information; I'm reading the paper we're talking about. The rapidly evolving region showed nothing but "letter changes" -- eighteen of them.

You can't improve a computer program by changing a few 0's to 1's. It takes a number of changes to make the program comparatively better (for a specified purpose), and those changes have to be coordinated and organized.

Right. And that would be relevant if we were talking about evolving computer programs, but we're not. Genes can indeed change for the better (in a particular environment) with just a single change. What is your basis for saying that they can't?

I have no problem believing that information in a peice of DNA can be erroneously copied, and through additional errors than peice of data is changed. Still, you have one set of information that is either copied or changed, but no new information added to the system, with information being organized data that carries a purpose or message.

If you change the DNA, you change the message. DNA's message is "build a protein with these amino acids", or "build this protein when the insulin level is high", and things like that. If the message says something different than it did before, how is that not new information?

a few changes in A's, G's, and T's doesn't add new features or make any large changes to an organism.

A few changes in individual nucleotides generally doesn't make a large change to an organism. It makes a small change. Then a few more changes make another small change. And then a few more changes make another small change. And on, and on, for thousands of iterations. Changes do add up after a while.

We are too complex for that. It takes larger-scale mutations to make significant, advantagous changes. Those mutations either copy existing information, change peiced of existing information, or delete information. Organized, new information doesn't just get mutated into an organism, and small information changes of DNA letters aren't enough to give an organism enough of a competitive advantage to be naturally selected.

I'm sorry, but that's just wrong. There are plenty of examples of a single nucleotide change giving a measurable competitive advantage, enough to be promoted by natural selection. I don't know where you're getting your information from, but it's not from biology.

 

[NASAg03]

"Purpose" and "message" are loaded, metaphysical terms when used a priori. They have no place in a scientific discussion.

DNA carries a message in the same sense that a binary program carries a message. in both cases, the organization of data fulfills a purpose. the DNA forms a living organism; the program accomplishes a designed task.

Or an amassing of smaller-scale mutations.

you assume that these building-blocks of mutations stay ordered and don't get mutated or lost in the species, allowing them to amass over thousands of years. it takes multiple, organized changes to result in a new feature that will give an organism a benefit over it's non-mutated friends.

What about nylon-eating bacteria?

multiple changes. 2 enzymes changed, one as single mutation, and the other was a frame shift and 48 other changes within the frame of the enzyme. the generalize evo statement is "it was just a frame shift that resulted in digestion of nylon". that's just a portion of the truth.

the fact is, multiple changes had to "randomly" occur and stay with the organism within 30 years to be beneficial. evo's don't deny that there were multiple changes necessary to disgest the nylon, but rather the probability to evolve to a beneficial point in that amount of time, by random mutations.

i don't think the mutations were at all random, but rather orchestrated for the purpose of breaking down nylon.

 

[NASAg03]

I'm sorry, but that's just wrong. There are plenty of examples of a single nucleotide change giving a measurable competitive advantage, enough to be promoted by natural selection. I don't know where you're getting your information from, but it's not from biology.

please reference an example of a single letter change that results in a significant competitive advantage. even the commonly referenced nylon bacteria was the result of 50 changes over 30 years which allowed to digest nylon.

 

[rmwilliamsll]

i don't think the mutations were at all random, but rather orchestrated for the purpose of breaking down nylon.


how would you design a scientific experiment to show the purposefulness of this mutation?

likewise how would you design an experiment to show that the mutation(s) were in fact random, unexpected, not purposeful and not teleologically driven?

hint:
create a thousand clone colonies of the bacteria and subject then to the nylon waste and see what happens.

do you expect all of them to "invent" the mutation?
if not how was "the purpose" of one clone colony distinction from another's?

say you get 2 colonies that produce a nylon digesting enzyme.
do you think they are the same mutation(s)?

repeat the whole experiment, do you think 2 colonies will arise in exactly the same way again?

repeat again, is the experiment reproducible?

 

[Chalnoth]

please reference an example of a single letter change that results in a significant competitive advantage. even the commonly referenced nylon bacteria was the result of 50 changes over 30 years which allowed to digest nylon.

It doesn't need to be significant, even a slight probabalistic advantage will improve survivability, and given many generations, will come to dominate the gene pool.

 

[rmwilliamsll]

please reference an example of a single letter change that results in a significant competitive advantage.


the most well studied are those that effect hemoglobin.
sickle celled anemia is one of thousands of thallesemias associated with areas endemic for malaria.

there are a number of interesting places to look

the gene for cystic fibrosis and Vibrio cholera infection
a number of brain proteins associated with tay sachs and eastern european jews and intelligence
CCR5 and the black plague

a little bit of googling can yield not only an education but an enjoyable afternoon of reading.

remember that competitive advantage is always associated with a context. what is an advantage in a malaria swamp is not necessarily advantageous in the center city of Chicago. but that doesn't deny the advantage of HbS in Africa.

 

[Tomk80]

please reference an example of a single letter change that results in a significant competitive advantage. even the commonly referenced nylon bacteria was the result of 50 changes over 30 years which allowed to digest nylon.

But only one was important, the frame shift mutation by an insertion of 1 base. The rest was tweaking, making the nylonase more efficient.

Other example is hemoglobin S, which gives a tremendous advantage in people having one copy of the allele, because it gives resistence to malaria. The newly evolved hemoglobin C, IIRC, is also the result of one mutation. That one is cool to the extreme, in that it provides the malaria resistence without the disadvantage of sickle cell.

 

[TeddyKGB]

DNA carries a message in the same sense that a binary program carries a message. in both cases, the organization of data fulfills a purpose. the DNA forms a living organism; the program accomplishes a designed task.

As long as you can avoid referring to DNA in teleological or metaphysical terms.

you assume that these building-blocks of mutations stay ordered and don't get mutated or lost in the species, allowing them to amass over thousands of years. it takes multiple, organized changes to result in a new feature that will give an organism a benefit over it's non-mutated friends.

Novel features are comparatively rare. Most phenotypic changes involve small modifications to existing features. It's actually pretty easy to see in transitional fossils like Archaeopteryx and Tiktallik.

multiple changes. 2 enzymes changed, one as single mutation, and the other was a frame shift and 48 other changes within the frame of the enzyme. the generalize evo statement is "it was just a frame shift that resulted in digestion of nylon". that's just a portion of the truth.

the fact is, multiple changes had to "randomly" occur and stay with the organism within 30 years to be beneficial. evo's don't deny that there were multiple changes necessary to disgest the nylon, but rather the probability to evolve to a beneficial point in that amount of time, by random mutations.

i don't think the mutations were at all random, but rather orchestrated for the purpose of breaking down nylon.

Orchestrated by whom?

 

[sfs]

please reference an example of a single letter change that results in a significant competitive advantage. even the commonly referenced nylon bacteria was the result of 50 changes over 30 years which allowed to digest nylon.

A single nucleotide substitution in the promoter for the Duffy blood antigen gene in humans confers resistence to vivax malaria.

A single nucleotide substitution in the pfcrt gene (changing amino acid lysine to threonine) in plasmodium malaria confers resistence to the drug chloroquine.

A series of four nucleotide substitutions in the dhfr gene in plasmodium malaria each confer increasing levels of resistence to the drug pyrimethamine.

A single nucleotide substitution in the HBB gene in humans confers substantial protection against falciparum malaria (as well as sickle cell disease).

Each of these mutations (taken from organisms I happen to know well) was beneficial enough to undergo positive natural selection.

(I would also bet a couple of dollars that the mutation that give northern Europeans lactose tolerance as adults will turn out to be a single-base substitution, but that hasn't been demonstrated yet. )

 

[sfs]

CCR5 and the black plague

This one doesn't count. It isn't a single letter change (it's a deletion of a group of base pairs), and it doesn't produce resistence to the black plague; there's no good evidence that it has been under selection. (Even though it does not produce resistence to AIDS.)