Meatros

I just recentally read How stuff work's article on evolution and I have some comments, some complaints, and some things I hope some of your bright minds can help with.

First, I thought it was a good introduction to evolution. With that said, I'm going to clarify by saying this: It was easy to understand and follow. I'm not an expert on evolution, the information presented *seems* to me to be fairly accurate (with a few exceptions), based on what I've read elsewhere.

My complaints are:
* The site doesn't separate evolution from abiogenesis (which I feel is important because as I've always understood it, evolution occurs *after* the first life 'glob' appeared. So whether or not abiogenesis happened via naturalistic means or (bear with me) supernatural means-it doesn't effect the ToE).

* This site doesn't make it clear that the argument isn't whether or not evolution occured, but rather *how* it has occured. The scientists who are investigating evolution are looking into how evolution happens, not whether it happened. Maybe it's me just nitpicking gnatshit, but I don't think this article made that distinction very well.

* At the end of the article, it's mentioned that Creationism is a serious contender. I don't think they emphasized the religious aspects sufficiently enough, nor the contradicting sciences (as in an Old earth, impossibility of a flood, etc) that generally go along with creationism. Now, I suppose the author could argue that what was meant by creationism was that 'God' created each separate species, or the starting species, or I dunno-my point is that it isn't very clear.

Okay, with my disclosure of my knowledge (albeit a little limited) of evolution and my problems with the article, I did have a few questions from the article that I was wondering if any of you bright minds knew:

1. The whole point about "adding information". I'd always thought that information was 'added' by mutations and that eventually one mutation would lead to an increase of genetic material. In any event, here's a quotation from the article:

Can anyone clarify this for me? The way I understand evolution is that this isn't necessarily a problem (ie, enough mutations can 'solve' this problem), this paragraph seems to suggest that species are more *fixed* (for a lack of a better word) then I've previously understood them to be.

2. IIRC the human Genome was mapped, via computers, is this correct? What further insights to evolution has this led to?

3. Is there a better, more indepth (yet as easy to understand article) article on evolution that this one (I'm sure there is)? I've printed out Talk Origin's "intro" and I've started to read a little bit of it, but I had these questions now (), and was hoping for some 'instant insights' .

lpetrich

Meatros on the "How Stuff Works" site:
* The site doesn't separate evolution from abiogenesis (which I feel is important because as I've always understood it, evolution occurs *after* the first life 'glob' appeared. So whether or not abiogenesis happened via naturalistic means or (bear with me) supernatural means-it doesn't effect the ToE.

That's right -- the origin of the first self-reproducing system is separate from what happened afterwards.

* This site doesn't make it clear that the argument isn't whether or not evolution occured, but rather *how* it has occured. The scientists who are investigating evolution are looking into how evolution happens, not whether it happened. Maybe it's me just nitpicking gnatshit, but I don't think this article made that distinction very well.

Important distinction; just what makes evolution happen has been a source of controversy, though the most successful hypotheses have been variants of the Darwinian paradigm.

* At the end of the article, it's mentioned that Creationism is a serious contender. I don't think they emphasized the religious aspects sufficiently enough, nor the contradicting sciences (as in an Old earth, impossibility of a flood, etc) that generally go along with creationism. Now, I suppose the author could argue that what was meant by creationism was that 'God' created each separate species, or the starting species, or I dunno-my point is that it isn't very clear.

An important distinction -- between Flood-Geology young-earthism and special creations of species over geological time. Especially special creations that are carefully set up to look like evolution.

lpetrich

Meatros:
1. The whole point about "adding information". I'd always thought that information was 'added' by mutations and that eventually one mutation would lead to an increase of genetic material.

There is more than one kind of mutation.

Point mutations: alteration of a DNA or RNA base.
Insertions and deletions.
Unequal crossover of chromosomes.

As to "information", creationists usually turn weaselly and evasive when asked what they mean by it. There are some technical conceptions of it, however:

* The number of yes/no questions needed to distinguish various possible states of a system (classical or Shannon).

* The length of the algorithm necessary to compute a system's state (Kolmogorov).

In any event, here's a quotation from the article:

Quote:

Evolution's mutation mechanism does not explain how growth of a genome is possible. How can point mutations create new chromosomes or lengthen a strand of DNA? It is interesting to note that, in all of the selective breeding in dogs, there has been no change to the basic dog genome. All breeds of dog can still mate with one another. People have not seen any increase in dog's DNA, but have simply selected different genes from the existing dog gene pool to create the different breeds.

Can anyone clarify this for me?

First, what's meant by the "basic dog genome"?

Furthermore, it is unlikely that all the versions of genes in the various dog breeds were pre-existing -- which is what that comment seems to imply. Many dogs have features that depart rather dramatically from their gray-wolf ancestors or from most other canids, like coyotes and jackals and foxes -- which suggest that they were the result of mutations selected because their owners liked them.

There is also an easy way to lengthen the genome. Gene duplication. Including whole-genome duplication (polyploidy) -- which sometimes happens!

And the two copies of a duplicated gene can go their own separate ways, becoming adapted to different functions.

The way I understand evolution is that this isn't necessarily a problem (ie, enough mutations can 'solve' this problem), this paragraph seems to suggest that species are more *fixed* (for a lack of a better word) then I've previously understood them to be.

More likely, the writer of it had certain misunderstandings.

2. IIRC the human Genome was mapped, via computers, is this correct? What further insights to evolution has this led to?

It's been stitched together from sequenced fragments -- and computers were an absolute necessity for this task.

And yes, having a whole genome on hand has led to some very interesting insights -- especially as a result to comparing it to other sequenced genomes. Some of what's been sequenced so far:

Our own species
Chimp (in progress)

Mouse
Rat
Dog (will start soon)
Cow (may start soon)

Chicken (in progress)

Some frogs (in progress)

Zebrafish (in progress)
Pufferfish

Sea squirt

Fruit fly
Malaria mosquito

Nematode

Yeast

Arabidopsis mustard weed
Rice

The malaria bug

A slime mold (in progress)

> 100 bacteria

Roller

You might want to take a look at this:
http://www.talkorigins.org/faqs/comdesc/section4.html

Meatros

Thanks for the corrections and updates .

This is what I was (sort of) thinking. Now, to me the article seemed to imply (or I'm just totally off base) that additional chromosomes aren't able to be "added". If that was the case though, what about Down's syndrome and IIRC the combination of different species (ie, IIRC a tiger and a lion that have been shown to mate successfully-I don't have an article, but it was on the discovery channel, during the "oscar" chimp/human program).

What do you mean by classical or shannon?

That's what I figured, but I did want to check it out first . As I said, I'm not by any means an expert on evolution, but I'm willing to learn.



Also, thanks for the article Roller! I think I'll read that after I finish talkorigin's "intro".