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Evolution and Chromosomes


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I read this somewhere...

 

"Natural selection is a scientific fact but the trouble with darwinian evolution is that you have creatures turning into other creatures such as a dog turning into a whale which is beyond ridiculous. There is no scientific evidence that a species can change the number of chromosomes within the DNA. The chromosome count within each species is fixed. This is the reason a male from one species cannot mate and evolve successfully with a female of another species. Man could not evolve from apes. Each species is locked into its chromosome count that cannot change. If an animal developed an extra chromosome or lost a chromosome because of some deformity, it could not successfully mate and evolve a new species. The defect could not be passed along to the next generation. Evolving a new species is scientifically impossible. "

 

Is this true? How is evolution possible then?

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the trouble with darwinian evolution is that you have creatures turning into other creatures such as a dog turning into a whale

 

Evolution doesn't suggest that such a thing is possible. It is beyond ridiculous for someone to claim it does.

 

There is no scientific evidence that a species can change the number of chromosomes within the DNA.

 

There are lots of examples of this.

 

Evolving a new species is scientifically impossible.

 

And yet it happens.

 

Some examples (of both changes in chromosome number and new species) here: http://www.talkorigins.org/faqs/faq-speciation.html

 

That site also has answer to pretty much all these creationist lies. Worth browsing.

Edited by Strange
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Lots of smoke and mirrors there. Dogs don't turn into whales, but they can certainly evolve that way. And we didn't evolve from apes, we evolved alongside apes from an ancestor we both shared. Big difference, don't trust the weasel words.

 

And there IS scientific evidence that the number of chromosomes can change. But if they get you to believe it isn't possible before you check the facts, it's much more likely you'll believe the lies.

 

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Natural selection is a scientific fact but the trouble with darwinian evolution is that you have creatures turning into other creatures such as a dog turning into a whale which is beyond ridiculous.

 

It is ridiculous. It's also a strawman argument I often find difficult to understand why people repeat. The claim of evolutionary theory is that vertebrates have a common ancestor. You and your second cousins have a common ancestor in your great grandparents. That is a totally different claim than your child turned into your second cousin. Shared ancestry is not equivalent to one thing turning into another.

 

There is no scientific evidence that a species can change the number of chromosomes within the DNA. The chromosome count within each species is fixed.

 

This simply wrong. See polyploidy. I would suggest whoever devised the argument is ignorant of basic biology.

 

 

Man could not evolve from apes. Each species is locked into its chromosome count that cannot change.

 

Again, simply false. See Roberstonian translocation. Mouse populations can have between 40 and 60 chromosome pairs and are not reproductively isolated http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8312.2005.00454.x/abstract

 

If an animal developed an extra chromosome or lost a chromosome because of some deformity, it could not successfully mate and evolve a new species. The defect could not be passed along to the next generation. Evolving a new species is scientifically impossible. "

 

 

Again, simply false. See chromosomal speciation.

 

The explanation is for all intents an purposes, completely wrong.

Edited by Arete
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The main thing I want to know about is how to disprove "If an animal developed an extra chromosome or lost a chromosome because of some deformity, it could not successfully mate and evolve a new species."

 

As I mentioned, it's easy because of the numerous examples of intraspecific karyotypic variation which disprove it.

 

The most notable example is Mus musculus domesticus - the house mouse, which has 97 known chromosomal arrangements distributed across its distribution, ranging from 2n=22 to 2n=40 chromosomes, with between 2 and 25 chromosomal rearrangements. http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8312.2005.00454.x/abstractThis comprehensively dismisses the claim that chromosome number is fixed within a species, and that a chromosomal rearrangement renders an individual sterile.

 

It's also not just mice - here's examples in bats, mosquitoes, sponges, lizards, frogs, gophers ... you get the idea. Chromosomal variation is also quite common in plants - more so than vertebrates - the famous biologist George Stebbins did a lot of work on karyotypic evolution in plants.

 

​Ultimately the claim is simply wrong. Chromosome number isn't fixed within every species, and chromosomal rearrangement doesn't result in sterility - approximately 1 in 1,000 people have a robertsonian fusion, and thus 45 or even 44 chromosomes instead of 46. The majority are perfectly healthy. http://en.wikipedia.org/wiki/Robertsonian_translocation

Edited by Arete
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​Ultimately the claim is simply wrong. Chromosome number isn't fixed within every species, and chromosomal rearrangement doesn't result in sterility - approximately 1 in 1,000 people have a robertsonian fusion, and thus 45 or even 44 chromosomes instead of 46. The majority are perfectly healthy. http://en.wikipedia.org/wiki/Robertsonian_translocation

 

And since the creationist site that made this claim had access to all this information, it's left to the reader to decide whether they made a bad, uneducated guess about chromosomes and reproduction, or they deliberately lied to sneak their arguments past those who trusted them to be using actual facts.

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And since the creationist site that made this claim had access to all this information, it's left to the reader to decide whether they made a bad, uneducated guess about chromosomes and reproduction, or they deliberately lied to sneak their arguments past those who trusted them to be using actual facts.

In the world at large, when things are wrong, I generally favour incompetence over intent. (Although when I used that excuse with the magistrate as an explanation for non-payment of a speeding ticket she fined me an extra £50.)

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In the world at large, when things are wrong, I generally favour incompetence over intent.

 

Misrepresentations like the OP sort of straddle the fence, imo. I think it's intentionally deceptive to offer an assertion extracted from one's posterior, but that sort of behavio(u)r is a hallmark of the incompetent.

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Plants are actually the ultimate example. Polyploidy, both auto (genome doubling) and allo (hybridization between species) is extremely widespread and has occurred numerous times, even in the course of modern man. Many of our most prominant crops species (wheat, barley, brassicas, etc) have undergone polyploidization...especially allopolyploidization....during the course of domestication. Bread wheat is a hexaploid resulting from two seperate hybridization events during the course of domestication by humans leading to a species that now contains three genomes.

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