DNA length

Louis van de Zande ZANDELPW at biol.rug.nl
Fri Jun 10 02:32:49 EST 1994


> Hi, 
> 
> I was wondering if anyone can shed light on some things for me.
> Apologies if this is the wrong place to ask.
> 
> Q1. Is the length of the DNA the same among all members of the 
>     same species?
> 
> Q2. Are the lengths of DNA in different species all different?
> 
> Q3. Can offspring of a species have different length DNA from
>     their parents and survive?
> 
> Q4. If Q2=Yes, how do evolutionists explain how the DNA length
>     changes during evolution into a new species?
> 
> Thanks for any replies.
> 
> Alan Wong (atc.wong at ic.ac.uk)
> 

As usual, it all ends up as a matter of scale. Are you talking 
chromosomes, megabases, kilobases or even smaller. At the nucleotide 
level even different individuals have different numbers of them 
(funny enough this allows different individuals from differen species 
to have exactly the same number of nucleotides in their genomes).
Generally, I think the answer to the first two questions is: no.
The third question has consequently to be answered by: yes (Down's 
syndrome?)
As to the 4th question: DNA is a flexible and adaptive molecule. It 
will not sit back and relax after a good period of strenuous 
evolution. So it will recombine and shuffle and...well anything that 
causes change and hence length polymorphism.
I realize the basic simplicity of this answer.
Cheers
Louis v.d. Zande







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