Something a Creationist sent me about evolution. Not sure what he's getting at?

Pathofreason
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Something a Creationist sent me about evolution. Not sure what he's getting at?

He said: 

 

Species is define as "(biology) taxonomic group whose members can interbreed ", meaning members of different species cannot breed and produce viable offspring who can also reproduce (think horse + donkey = mule but a mule is sterile, so it is not a species) there has to be a difference major enough for the species to not be able to cross-breed. According to the theory of evolution, the way a new species comes about is by beneficial mutation, correct? This mutation is random, but since it is beneficial the individual survives better than the others, and reproduces. Eventually, the mutation becomes genetically prominent enough to be a dominant gene in the species gene pool, correct? This has never happened with any current species and the continuing experiment with fruit flies proves that it can't happen, because each time a mutation happens, it is not beneficial, and the offspring is usually sterile, eliminating the useless gene from the gene pool. Only minor variations have been observed and do not produce a new species because they are still able to mate with the original fruit fly specie, and create viable offspring. Darwin didn't know what happens inside cells to make them split, or he might have reconsidered his theory. The process is extremely complicated and scientists have still not figured out how it happens, all we know is data is stored in a quaternary double helix, we don't know how it can contain enough data to map out an entire organism. Until we know exactly how DNA works, I don't see the reason of thinking we know how individual species came about.

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Frankly, it sounds like he's

Frankly, it sounds like he's claiming that speciation happens in one generation, and thus can't happen because there'd be no others of its species to breed with - or can't breed with the previous species because it would produce sterile offspring.... I think.

Plus a fascinating assertion about there never having been a benificial mutation among the gadzillions of fruit flies bred. Clearly not so.

And another assertion that we're ignorant of cellular function. I think that'll come as a suprise to Deludedgod.

Eh. I'm not being a lot of help here. It just looks like another creationist demonstrating incredible ignorance of evolution and biology.

"Anyone can repress a woman, but you need 'dictated' scriptures to feel you're really right in repressing her. In the same way, homophobes thrive everywhere. But you must feel you've got scripture on your side to come up with the tedious 'Adam and Eve not Adam and Steve' style arguments instead of just recognising that some people are different." - Douglas Murray


Hambydammit
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Quote:Species is define as

Quote:
Species is define as "(biology) taxonomic group whose members can interbreed "

Not really.  First, the concept of a species was invented before we knew that all life was related.  It's not a very good classification system.  In fact, some species can interbreed but simply don't, due either to geographic isolation or some other factor.

Also, the term species breaks down rather significantly when we start talking about bacteria.  It's rather technical, and I'm not inclined to type it all out right now.  I'm sure deludedgod has covered it in one of his book pages.  The short version of it is that A) species is an outdated term, and B) it's not true that no species can interbreed.

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According to the theory of evolution, the way a new species comes about is by beneficial mutation, correct?

That is one way a new species comes about.

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This mutation is random, but since it is beneficial the individual survives better than the others, and reproduces.

Remember, there are other influences besides random mutation.  Changes in predation can make previously detrimental aberrations into beneficial traits.  Consider a population of brown beetles where one in a hundred turns out green.  While the desert is brown and dry, the brown beetles have the "best" genes.  When El Nino comes around and turns the desert into a lush plain, the greens suddenly have the good genes, and the browns suffer from bad genes.

Some of these variations in phenotype expression are due to normal recurring patterns in outcrossing.  That is, a certain combination of highly successful genes happen to form a "bad" combination when they get together in a particular way, which has a certain probability.

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This has never happened with any current species and the continuing experiment with fruit flies proves that it can't happen, because each time a mutation happens, it is not beneficial, and the offspring is usually sterile, eliminating the useless gene from the gene pool.

Horse shit.  First, every species is evolving right now.  Decent with variation.  That's all there is.  There is no such thing as a completely stable species because every offspring is a brand new combination of genes.  The species like sharks and roaches, that don't change much for millions of years, don't change much because there's no selection pressure moving them in any particular direction.  They are about as well adapted to their current environment as they can be.

Second, we have seen first hand empirical evidence of beneficial mutations.  Most recently, a strain of E coli learned how to eat a new kind of food and began reproducing much faster than its culture-mates.  The food a bacteria eats is one of the main thing that gives it a taxonomic classification.  We have even seen beneficial mutations in humans.  For instance, we are seeing a number of variations in a gene that deals with the digestion of lactose -- something that has only been necessary in humans since the domestication of cattle and other milk-giving creatures.

As a general rule, about 99 in 100 mutations are neutral.  There's a lot of junk DNA in most genes.  If they mutate, no biggie.  While it's true that beneficial mutations are substantially less common than harmful ones, there are several parts of the theory which explain how they are either corrected, weeded out of the gene pool, or reduced to recessiveness, which significantly reduces their impact on the population.  If you think about this, it's not to difficult to grasp.  Except in humans, babies with severe birth defects die soon after birth.  Even mild negative mutations will tend to weed themselves out much faster than beneficial ones, even if they are less numerous initially.

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Only minor variations have been observed and do not produce a new species because they are still able to mate with the original fruit fly specie, and create viable offspring.

Ok, I don't have the desire to look this up right now, but in the bacteria, it took tens of thousands of generations of isolating one strain before a beneficial mutation turned up.  Evolution doesn't predict large immediate changes.  It predicts minor variations which, over a long period of time, add up cumulatively into large changes. 

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Darwin didn't know what happens inside cells to make them split, or he might have reconsidered his theory.

If he had known about DNA, he could have made much more accurate predictions than he did, but all things considered, he nailed it pretty much square on the head.

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The process is extremely complicated and scientists have still not figured out how it happens, all we know is data is stored in a quaternary double helix, we don't know how it can contain enough data to map out an entire organism.

Ok, this is utter horseshit.  First of all, you need to understand something about information theory.  Much of what "builds" an organism is actually repeated information.  In a centipede, you don't have a gene that says, "Build section 2, with one leg on each side," and another that says, "Build section 3, with one leg on each side," and so on for each of thirty or so sections.  You don't really have one gene that "says" anything of the sort, but for the sake of simplicity, we can imagine that one gene says something like, "Build a segment to such and such specifications, with legs."  Another gene says, "Build all appendages in pairs, one on each side of the body," and still another says, "Build thirty segments in a row."

So, to get a centipede with a head section, a tail section, and say, thirty torso sections, you need about five or six genes.  Of course, I'm oversimplifying to the point of absurdity, but I'm doing it to show you that each part of an animal can be broken down into "rules" which translate very well from other parts.  A lot of the information is actually not unique.

Furthermore, you must understand that there is a great deal of variation built into even a single gene.  To put it simply, in many genes, there are "alternate spellings" of various proteins which can create incredibly large numbers of variations through gene splicing.  Consider that in the fruit fly, there's a single gene that, in theory, can express somewhere near 20,000 proteins just from one set of alternate spellings!

Now, consider 25,000 genes or so, and then consider that a significant portion of them can express ridiculously large numbers of alternate proteins.  Now, remember that these genes are going to experience recombination and outcrossing, where they will mix with another set of 25,000 genes.  No, this guy is just completely wrong.  Not only is there enough DNA to make complex creatures, there's enough left over for us to have tons of junk just sitting around in our genes.

Of course, you can go all anthropic, too.  I mean... duh... we're here, and we are certainly built by genes.  Therefore, the genes have enough complexity to make us.

Quote:
]Until we know exactly how DNA works, I don't see the reason of thinking we know how individual species came about.

A better way of saying this would be, "Until people like me know more about how DNA works, I don't see any reason to think anyone should take my opinions seriously."

 

 

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Pathofreason
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His additional response

The extra data in DNA aren't "useless junk genes", they are used when natural selection is needed. Natural selection is not evolution. A white rabbit and a brown rabbit are the same species, Black people and white people are the same species. They are different because they had to adapt to their surroundings. White rabbits are more common in the tundra and areas where it snows a lot. Black people are prominent where it is hot and sunny. Natural selection does no create new species. A finch with a rounded beak is the same species as a finch with a sharp beak.

Of course we can go backwards and say "since we exist and we were built by DNA, obviously the DNA contains enough data to 'write' us into existence"
That is obvious, but we have no idea what those formulas are, or how they are stored, or how stem cells "know" which cell to reproduce. If we knew the secrets of DNA then they would be able to create life in a lab, and who has done that? We know what makes up life, so why can't we create an artificial bacteria that reproduces itself? If this has been done, please let me know, because my searches are coming up empty.

You still haven't given me a logical explanation for macro-evolution, or cross-special evolution. You have described micro-evolution, and suggested that evolution occurs in asexually reproducing organisms, which I can agree with since there is no clear species in asexual organisms and mutations do not render them sterile. And, they don't need a mate with the same mutation(s) to propagate the mutation in the gene pool.

My entire argument is based on sexually reproducing organisms, even something relatively simple like a gnat.
btw, my definition of species is from Princeton, you can't really argue with that. (well you can but i wont believe you)
http://wordnet.princeton.edu/perl/webwn?s=species

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Hambydammit
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Quote:The extra data in DNA

Quote:
The extra data in DNA aren't "useless junk genes", they are used when natural selection is needed.

At this point, you can stop talking to him.  He's completely ignorant.

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. A white rabbit and a brown rabbit are the same species,

Didn't I cover species earlier?  Let me say it again:  Species is an outdated term that was invented before we knew about DNA and that all life is related.  Brown and green beetles are the same as octopus and human.  They're just separated by millions and millions of years.

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That is obvious, but we have no idea what those formulas are, or how they are stored, or how stem cells "know" which cell to reproduce

Please, kind interlocutor, never make the mistake of thinking that because you, or your pastor, don't know how something works, that nobody knows.  We have very specific knowledge of how a great deal of the DNA code works.  I'd expound, but unless you understand the very fundamentals of evolution, (you clearly don't) it would be like trying to teach calculus to someone who doesn't understand algebra.

Here's a website for you:

http://www.dnaftb.org/dnaftb/1/concept/

It's got pictures.  Should be on your level.

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If we knew the secrets of DNA then they would be able to create life in a lab

We know the secrets of lots of things that we can't just create at will, dude.  You're talking about several things at once.  First, understanding how DNA works is NOT the same as knowing what the first replicator was.  It was most assuredly not DNA.  The thing is, it could have been any number of possible configurations of any number of possible chemicals.  Microscopic chemicals don't leave fossils, so we're having to make educated guesses as to what preceded RNA and DNA.  These are two very different topics.  Even so, we have come very, very close to creating replicators (life) in the lab.  I wouldn't be a bit surprised if we created a self sustaining replicator in the next few decades.

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We know what makes up life, so why can't we create an artificial bacteria that reproduces itself?

Because a bacteria represents the MIDDLE of the chain.  The first replicator wasn't DNA or even RNA.  Besides that, natural selection is very, very fickle, and is dependent on the environment, so we would have to know the exact conditions, and the exact series of environments that facilitated millions of years of change.  We wouldn't be able to create bacteria from scratch.  We'd have to create something that would evolve into bacteria in a few million years.  This isn't that hard to understand.

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You still haven't given me a logical explanation for macro-evolution, or cross-special evolution.

That's because there's no such thing.  There is only evolution.  When there's a tiny mutation, we don't bother saying something is a new species.  Once a thing has accumulated fifty thousand or a hundred thousand new genotypic variations, and has been separated geographically, or otherwise isolated such that it shows enough genotypic variation to call it something else, we do.

I get what you're asking, though.  You want to know how a two animals can be able to reproduce together, and then suddenly, they can't, right?  Ok.  Here's a general idea of how it happens.  Imagine a frog.  Any old frog.  Doesn't matter.  This frog lives in trees and eats moths.  Everything's fine, until one day, there's a huge flood, and half of the forest becomes submerged.  The trees die, and in a few decades, there's a marsh now instead of a forest.  In those few decades, there have been a thousand or so generations of frogs, and their population has been decimated.  However, like the brown and green beetles, a few of the frogs were lucky enough to be able to eat water spiders.  They survive quite well, and within a decade or two of the marsh taking hold, this slight variation has allowed water spider eaters to proliferate, while the moth eating variety has died out.  (Remember, they're still fine in the forest that didn't turn into marsh.

As centuries pass, a few of the frogs develop a neat little mutation.  Their toes, which were thin and sticky to grasp branches, become slightly wider.  This gives them a slight advantage when they have to jump in the water to catch their spiders.  It turns out to be a big advantage, and soon, only frogs with wider toes are around.  This process repeats for a few thousand years until all of the frogs have huge feet that are no longer sticky... after all, they haven't climbed trees for food in thousands of years!  There was no reason for that trait to continue to proliferate.

Now, at this point in their evolution, the two types of frog -- tree and water -- might well be able to reproduce, but they're not going to.  That's because neither goes to visit the other anymore.  The two populations have become isolated.  Now, give this another million years, and other mutations are likely to develop.  Suppose the overall size of the water frog increases such that its genitals are no longer compatible with the tree frog's.  Just one little mutation, a little runaway selection, and whammo... huge frog genital.

Runaway selection, by the way, is when a new mutation works really well, females dig it, and suddenly it spreads through the whole population like wildfire.  Anyway, that's one example of how a speciation event can occur.   

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You have described micro-evolution, and suggested that evolution occurs in asexually reproducing organisms, which I can agree with since there is no clear species in asexual organisms and mutations do not render them sterile.

Was that me?  I don't recall mentioning anything about asexual reproduction in this thread, but if I did, so be it.  Here's a neat article I wrote about sexual vs. asexual reproduction.  What's So Great About Sex?

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btw, my definition of species is from Princeton, you can't really argue with that. (well you can but i wont believe you)
http://wordnet.princeton.edu/perl/webwn?s=species

That's a fine definition.  For most purposes, it works fine, but that doesn't change the fact that THE WORD WAS INVENTED AND DEFINED BEFORE WE KNEW ABOUT GENES.

Do you get that?  The definition is correct.  It's absolutely and wonderfully correct.  Species is pretty much defunct in evolutionary biology.  It's still used loosely as a descriptor, but the main way organisms are classified now is cladistics, which reflects genetic relation instead of morphology.

 

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