They want to forget Darwin ... [help]

[brianleahy]

Speaking personally (and as my earlier posts reveal) I accept the geologic age of the earth, of about 4.5 billion years. The figure of 6000 years is not in the Bible, per-se, but it is a figure adopted by some Christian sects (such as Mormons, I believe).

A Google search reveals that this figure is credited to "James Ussher, Anglican Archibishop of Armagh and Primate of All Ireland." (I cannot help but grin at the fact that this priest, who would surely have denounced evolution if he had lived to see it proposed, bore the title of "Primate".)

A description of his method is here: http://www.lhup.edu/~dsimanek/ussher.htm

 

[dlloyd]

Hmm, well I don't agree with that link

I feel that the creationist story is more of a metaphor than actual fact.

 

[MDLarson]

I haven't heard that mtDNA stuff before Brian, I'd like to follow up on that.

As far as the evolution between species like dogs or plants or humans etc., the correct term for that is microevolution. Creationists have no problem with that, as it does not and cannot create new species over time. Macroevolution is what evolution is generally regarded as, or one species coming out of another.

I was taught that peppered moths of the industrial revolution were a prime example of evolution in progress, but when I tried to tell my teacher that no new species was created in the phenomenon, she still insisted it was "the real deal".

Anyway, gotta run, it's late.

 

[brianleahy]

Hmm, well I don't agree with that link

Lest there be any confusion, neither do I.

Or to be more specific, although the link may be an accurate account of a 17th century Archbishop's teaching, I do not agree with the Archbishop.

 

[dlloyd]

Hmmmm, MD. Sounds like a stupid teacher .
However, don't you agree that eventually, if left apart long enough, Chihuahuas and Great Danes could become separated as a species? Yes, at the beginning of the evolution process for humans we were probably able to mate with some form of large ape too, but obviously we can't do that anymore.

 

[brianleahy]

we were probably able to mate with some form of large ape too, but obviously we can't do that anymore.

It's funny you should bring that up, I was thinking of mentioning this anyway: As repulsive as it sounds, some scientists believe that it might be possible to breed humans with chimps.

There is some precedent for different, but related, species to be able to breed. In captivity, Lions and Tigers sometimes mate, to produce Tigons or Ligers (by convention, the father cat provides the first syllable). Read about & see pix of these hybrid cats here: http://www.shambala.org/images/02_Animals/patrick.htm

Also, horses and donkeys can mate to produce a Mule - a live, viable hybrid, though usually sterile.

Comparisons of human vs. chimp DNA reveals greater similarity than a comparison of horse & donkey DNA, so it seems reasonable that if horses & donkeys can breed, humans & chimps might also be able.

So far as I know, nobody has yet dared try it - in vitro or otherwise. And if you think human cloning has stirred up controversy and outrage, just imagine the furor over an actual chimp-man...

But my question (especially for MD) is: if it happened, if some unscrupulous researcher successfully bred a chimp/human hybrid, proving that it could really be done, would this seem to you persuasive evidence that modern chimps and humans are, literally, related?

 

[dlloyd]

To me, yes I think so. And aren't Mules always sterile?

 

[brianleahy]

To me, yes I think so. And aren't Mules always sterile?

I think that most biological texts you might consult would say yes. However, having several farmers in my extended family, I have heard anecdotal evidence that now and then female mules have become pregnant. Nothing you could publish in Nature, but...

 

[markceltic]

It's funny you should bring that up, I was thinking of mentioning this anyway: As repulsive as it sounds, some scientists believe that it might be possible to breed humans with chimps.



So far as I know, nobody has yet dared try it - in vitro or otherwise. And if you think human cloning has stirred up controversy and outrage, just imagine the furor over an actual chimp-man...

I say if this was to happen the creature should be immediately destroyed.We have no business mucking about in the DNA that fundamentally makes us who we are.I suppose next someone wants to create a "super soldier".

 

[dlloyd]

"Genetically Modified Humans". Hmmm, wonder if they'd taste good, lol

Honestly, sounds like something from a science fiction book

 

[brianleahy]

I would not condone the creation of such a hybrid either. Even setting aside religious objections (bestiality is explicitly forbidden in the Bible, though it's an open question whether this proscription applies only to sexual acts or if it would extend to in-vitro fertilization) there are serious ethical and legal issues.

Such a hybrid might - indeed, probably would - suffer numerous health problems. The creature might be nearly as intelligent as a human, but it would have absolutely no prospect of living anything resembling a normal life, as either a chimp or a man. And what legal rights would it have? A human donor would have contributed half of the DNA - would that donor be obliged to support and care for the hybrid?

With the current pace of both computer technology and DNA/biological research, I think it's likely that within a few decades it will become possible to enter any hypothetical genome into a computer program and simulate its development (or failure to develop) from fertilized egg into living creature. At that point, perhaps we can safely and ethically examine the result of a chimp/human cross.

 

[MDLarson]

Hmmmm, MD. Sounds like a stupid teacher .
However, don't you agree that eventually, if left apart long enough, Chihuahuas and Great Danes could become separated as a species? Yes, at the beginning of the evolution process for humans we were probably able to mate with some form of large ape too, but obviously we can't do that anymore.

I've been typing and erasing my response to this question for 5 minutes now... lol! Having a hard time articulating.

I am not an expert, but I think they will still be 'dogs'. No new genetic information has happened in your example; they simply 'stayed the same'. If anything, genetic information would be lost due to the maintenance of the pure-bred, and in the end be an argument against evolution not for it.

This talk about ligers, tigons and mules is interesting, but unless these animals produce fertile offspring capable of passing on the genetic information, it's not evolution. Even if the offspring were fertile, I'm not sure it would be evolution in action.

Question for the evolutionist mathemetician: You say that sexual animals evolved from asexual animals. Asexual animals require no male or female for reproduction-it's all handled by the single animal.

Now, keeping in mind that mutated genetic traits must be passed down to successful offspring for evolution to work, think about how both male and female sets of sex organs had to evolve simultaneously for sexual reproduction to work. If a fledgling "female" (we're talking transitional forms here) had something just a little bit wrong with her sex organs, the male (we'll just assume his parts are working fine) would not be any help at all to the evolutionary process.

I'm with Sir Fred Hoyle on this one, so please, try to explain how this process would work to me, as I view this process as truly, practically impossible. I don't care if you give it billions or even trillions of years, I still think the probability of this happening is pretty much ZERO. If you don't see the problem I see, let me know and I can try to articulate a little better.

 

[dlloyd]

Now what about things like snails which are capable of both?
And if, as you say, "genetic information would be lost due to the maintenance of the pure-bred" wouldn't that be evolution? The genetics are still different

 

[MDLarson]

Now what about things like snails which are capable of both?

Ah, I was not aware of that - good point. I think you're suggesting that a species would maintain both methods of reproduction until one emerged as the advantagous trait and the other was eventually dropped. But you must now explain to me why an animal capable of such a feat would even bother to use the sexual method if it is clearly more of an advantage as a species to use the asexual method? The organism would have to find a mate whose own sex organs functioned well enough. The odds are still staggering, in my opinion.

And if, as you say, "genetic information would be lost due to the maintenance of the pure-bred" wouldn't that be evolution? The genetics are still different

Yes, the genetics are still different, but information is LOST, not GAINED. You could label it "evolution", strictly speaking because it is "change", but it does NOT solve the evolutionist stance of simple > complex in the species.

 

[brianleahy]

Well first, I did not mean to imply that the creation of 'mules' and other sterile hybrids was an example of evolution.

Rather, I meant that the fact that creatures that are irrefutably different species can sometimes produce even a living offspring suggests that the two species have a fundamental biochemical commonality, consistent with their having a common primordial ancestry.

If instead, each species was created in a seperate act of creation (and God did not INTEND them to interbreed) then why would their DNA be compatible at all? It is, clearly, possible to create genetically incompatible creatures - you can combine owl sperm with trout eggs as many times as you want and get zilch - so why didn't God make every species mutually incompatible?

As for how sex evolved -- first, with regards the compatibility of sex organs, realize that it is misleading to think of sexual organs as developing independently and thus raising the risk of incompatibility. (And obviously, any mutation which suddenly produced incompatible sex organs would immediately go extinct, since its owner could not reproduce.) The entire function of the sex organs is to facilitate a successful mating, and so male and female sex organs evolve as a set, not independently. Men and women are not different species which somehow discovered they could miraculously team up and make babies - they are two different expressions of the same genome.

Furthermore, sexual reproduction can and does exist WITHOUT interlocking sex organs. Dlloyd gives a great example: snails. Strictly speaking, snails reproduce sexually, yet are sexless. That is, there are no male or female snails -- any two snails can mate, and both may become pregnant as a result.

Then there are fish. Most fish species do not, technically, mate. They pair up, and the female lays her unfertilized eggs on the floor of the ocean/lake/river -- and then the male applies his sperm to the eggs. Clearly in this arrangement, there is no requirement for any kind of mechanical compatibility between the sexual organs.

You may or may not know that there are creatures which can reproduce either sexually or asexually. The Paramecium (often studied by high school bio students) can reproduce by simple fission, producing two genetically identical offspring -- or it can exchange genetic material with another paramecium. The microbe has what is called an "oral groove", and during what is called 'conjugation', two paramecia align their oral grooves and exchange nuclear material. This process is *always* followed by the fission of both paramecia. This represents an intermediate step between purely asexual and purely sexual reproduction. It also shows that sexual reproduction began very humbly, at the single-celled level.

There are also plants - dandelions for instance - in which each individual produces pollen (sperm) and 'hopes' to attract the pollen of another dandelion via either an insect or the wind. If, however, no pollen is forthcoming, the flower will eventually bend its pistils all the way around until it can harvest its OWN pollen, and it produces seeds asexually.

I have to grant you though, at a common sense level sex seems like a particularly difficult thing for evolution to have produced. It has been the subject of countless books, articles, and doctoral theses. What I have seen and read has persuaded me that it can and did happen.

 

[dlloyd]

Ah, I was not aware of that - good point. I think you're suggesting that a species would maintain both methods of reproduction until one emerged as the advantagous trait and the other was eventually dropped. But you must now explain to me why an animal capable of such a feat would even bother to use the sexual method if it is clearly more of an advantage as a species to use the asexual method? The organism would have to find a mate whose own sex organs functioned well enough. The odds are still staggering, in my opinion.

Staggering, yes, as are many things (the size of the universe, the length of pi, and life itself), but still not impossible, or even improbable.
I would think (personal opinion, I've not actually got any fact to back this up) that beings would want to move away from asexual reproduction for the simple reason that inbreeding is bad. I would say this is instinct, which, if you like, could have been placed there by God. Doesn't the Bible have strong words regarding incest? Why should the rule be specifically different for humans than for other animals, or even plants for that matter? Of course, asexual reproduction is a good backup for when another 'specimen' of the opposite sex isn't available. Much like you would probably 'reproduce' with your sister/mother if you were the last two humans on the planet; it is a survival mechanism.

Yes, the genetics are still different, but information is LOST, not GAINED. You could label it "evolution", strictly speaking because it is "change", but it does NOT solve the evolutionist stance of simple > complex in the species.

So you look at genetics like Bill Gates looks at Windows? ie, it's only better if it's bigger? (yes, that was a cheap shot)

 

[dlloyd]

Hmm Brian, you have certainly 'outread' me on this subject . I hadn't remembered that snails are actually sexless, though I do remember remembering this at one point. However, I was going to cite the example of plants later on, and I did somewhat touch on it in the post immediately previous to this one.

Oh, and looking at some girls, I would say they're a separate species. Not all, of course (my best friend is a prime example), but some...

 

[lurk]

Humans spread out of Africa and eventually into Europe, Asia, etc. where the sun is not as intense and cloudy days are more common. At the same time, the cooler climates encouraged them to wear more clothing and stay indoors more. Thus the environmental and 'lifestyle' pressures to maintain a high degree of natural UV protection were eased. Paler skin colors could then emege.

This is an example of what might be called 'evolution by omission' -- a trait faded as the evolutionary pressure to maintain it was eased.

This is a bit late but...

Just to add a little bit here lighter skin has distinct advantages in cold or low light areas or the world. The problem is not with cancer but rather Vitamin D, which is naturally generated in your skin through exposure to sunlight. Fair skin can produce more Vitamin D with less light and so was beneficial to people who lived in colder climates where their skin was covered for the most part.

I would be one of those creationists who don't believe in a helpful [long-term / pass-me-down] mutation. Somebody on this forum once provided a case for a positive mutation, but I didn't follow up on it.

One quick one that comes to mind would be the gene for sickle cell anemia which is quite bad is you get two copies of it. While if you have one sickle cell gene and one normal gene you will be immune to the effects of malaria. So in regions where malaria is endemic you find lots of sickle cell anemia since if you are lucky enough to get only one 'bad' mutation you live in the presence of a nasty disease. Where there is no malaria pressures on the population this mutation is only bad and is almost nonexistent.

As far as the variation in the human species goes, I think it is analogous to the different breeds we see in dogs. I'm 95% sure "canine" consists of one "species," yet we have a huge variety of breeds that can (usually) inter-breed successfully. Given enough generations and selective breeding, one can eventually come out with purebreds or mutts. The genetic code is all there.

Similarly, Adam and Eve would have been created with all the genetic code for all the variation we see today in humans. I remember reading about one case in New Zealand or Australia where a black and white man and woman (I forget who was what) had two twins and one of the twins appeared completely black and the other completely white. The point is, we did not mutate our different features. These features are simply genetic traits.

Finally, the idea that Adam and Eve carried all of the genetic diversity we see today is impossible when you consider that they were only two individuals. This is actually an information theoretic issue if you think about it if you only allow for recombination for genetic change rather than mutation then that means that for each point in the human genetic code had to be present in these two individuals. There are four bases you can have so technically if each is present in the population then whatever pair Adam had Eve necessarily had the other. The problem is that the resulting gene that Eve has to carry would have no chance of being viable. In effect you are trying to compress too much information into too small of a space and as a result the compression is too lossy to be of value.

-Eric

 

[brianleahy]

The vitamin D angle -- excellent! I hadn't thought of that.

And I had not thought about the information issue, that's very good too...

Even if you didn't take it quite to the base-pair level, still Adam or Eve would have to have -- between the two of them -- every single recessive genetic trait we see today, including the many crippling genetic illnesses we see. The first generation of offspring would be fine, but a large fraction of the 2nd generation would be ravaged by horrible diseases, due to the unavoidable inbreeding. Nasty...

beings would want to move away from asexual reproduction for the simple reason that inbreeding is bad.

Many studies have shown that the genetic shuffling afforded by sexual reproduction is very advantageous, and produces an overall healthier and more robust species. Inbreeding is bad because you're just mixing two copies of the same genes, and running a high risk of getting two copies of a harmful recessive gene.

Anyway, it is believed an ancient organism which, like paramecium, could reproduce either sexually or asexually, found that the generations which conjugated more often usually did better, and more of its offspring lived to divide further. Any genetic components which encouraged more frequent conjugation would thrive, with ever more copies present.

Over time, it became an organism that would virtually ALWAYS mate before splitting, and finally, one that could not split without first mating.

Sex organs may have arisen as an expedient to conjugation; any mechanical advantage that might simplify the alignment of two paramecia's oral grooves would improve the odds of successful conjugation.

 

[dlloyd]

Here is a pretty good picture of a paramecium: http://micro.magnet.fsu.edu/primer/techniques/phasegallery/paramecium.html
And a diagram: http://science.kennesaw.edu/biophys/biodiversity/protista/protpix.htm#paramecium

Over time, it became an organism that would virtually ALWAYS mate before splitting, and finally, one that could not split without first mating.

Except for those which, like the snail, retained the ability to do it either way

I think the theory of evolution itself is probably accepted by everyone (it has to be). For example, if there is a litter of pigs born in the wild, and one is born with a genetical defect which means it has no eyes, this runt will almost certainly not live, because it isn't as 'well developed' as it's brothers and sisters, and will not be able to avoid danger properly. Now, if it did live, its offspring would quite possibly have the same defect as its parent. Since the runt won't live, you have an example of natural selection.
On the other hand, if this same litter of pigs was born with one member that possessed four eyes, two in the back of the head, this member would have a marked advantage to its siblings. It would (we're assuming it's otherwise healthy) almost certainly live, because of its greater ability to avoid danger. When it reproduces, you'll have a change of some of its offspring also having four eyes, and, with time, you might have a new species. This is also an example of natural selection.
I believe this is an example of the beginnings of evolution.
The only problem I can see with this is some people might say "well, what proof is there that it will turn out a new species?" To go back to the canine example, 'dogs' are actually quite young; only a few thousand years old. A very short time period in the process of evolution. They haven't had enough time to develop into a new species, but I think that with time a Chihuahua could very easily lose the ability to mate with a wolf. Obviously at the beginning of the split of two species, they will remain 'inter-mate-able,' at least for a while.
Which brings up another question. To my knowledge, a wolf and a fox cannot mate and produce offspring. How do you then account for the fact that the wolf and the fox look similar, have similar genetics, and in general, seem to share many things? Do you believe that all these were created separately?
Anyway, to go back to my previous statement, I think almost everyone has to believe in evolution to some point (how can you possibly dismiss proven evidence, unless you are totally mad?), but it appears that at least one group of people chose to believe that there can be no 'long term' evolution.

And I think we need to get some fresh blood in here to help MDLarson . Three against one isn't exactly a fair debate.