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Ricky
SFN Die Hard
USA
4907 Posts |
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R.Wreck
SFN Regular
USA
1191 Posts |
 Posted - 04/14/2004 : 15:55:58 [Permalink]
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Ricky:
I can't answer your question about the biological method for increasing the number of genes, but I can shed some light on the 2nd law.
First, the notion that the 2nd law implies that all things naturally go from order to disorder is not what the 2nd law is about. Although it is a way to visualize what is happening on the molecular level, you can't apply the disorder analogy any way you want. The 2nd law (and by definition, entropy) is really about determining if a thermodynamic process will occur spontaneously or if work must be applied to make the process happen.
The main point about the 2nd law that is always ignored by creationists is that is applies ONLY to a CLOSED SYSTEM. That is, a system where no work or energy cross the system boundary. In a closed system, a process will occur if the net effect is to increase the entropy of the system. Heat will spontaneously flow from a high temperature source to a lower temperature heat sink. You can get heat to flow from cold to hot (that's what air conditioners and refrigerators do) thus decreasing the entropy of the system, but you have to add work to the system, and it is no longer a closed system.
The earth is not a closed system. It is constantly absorbing energy from the sun, and radiating energy back into space. Biological entities are not closed systems. They constantly exhange work and energy with their surroundings. Since the 2nd law by definition only applies to closed systems, any attempt to apply it to evolution or genetics is, by definition, nonsense.
Hope that helps. |
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tomk80
SFN Regular
Netherlands
1278 Posts |
Posted - 04/14/2004 : 16:56:07 [Permalink]
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If I remember correctly, one of the mechanisms would be gene duplication followed by subsequent mutation.
So, one of the genes of an organism would be duplicated. After this the duplicated gene mutates, finally resulting in a new gene. This explains why genes for different functions can be so similar. Gotta run now, but I'll try to supply some more detailed explanation plus references somewhere during the week (if someone doesn't beat me to is). |
Tom
`Contrariwise,' continued Tweedledee, `if it was so, it might be; and if it were so, it would be; but as it isn't, it ain't. That's logic.'
-Through the Looking Glass by Lewis Caroll- |
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 04/14/2004 : 16:57:22 [Permalink]
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One way the number of genes can increase is through defects in the DNA-copying mechanisms. Some genes simply get copied twice when "building" an egg or sperm cell, and the extra copy winds up in a living child, if it doesn't code for something of which too much is a bad thing. Or, the copy may be non-functional, but turn into a functional gene for something other than its original purpose over many generations.
Down's Syndrome is an example of a duplication of genes which doesn't have a good effect (that we can tell right now).
Secondly, entire chromosomes can get duplicated. You've probably heard of XXY (Klinefelter Syndrome) or XYY (XYY Syndrone) humans. That's it happening. There's also Triple-X Syndrome. These are just examples, but like when a single gene gets duplicated, an extra chromosome can become mutated from the original, and perform new "tasks," over many generations.
Thirdly, in plants especially, the whole genome can get duplicated sometimes. One researcher discovered a new species of plant in his own lab. Seems one of his seedlings happened to have twice the number of chromosomes as the plants he'd been intending to grow. The two kinds of plants could not fertilize one another. This would provide a whole bunch of genetic material for mutation to "play with" over generations, as the original functions would still be intact on one set of chromosomes or another. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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tomk80
SFN Regular
Netherlands
1278 Posts |
Posted - 04/14/2004 : 22:22:14 [Permalink]
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These two links might be of some help:
http://www.talkorigins.org/faqs/faq-intro-to-biology.html
There is a whole part on mechanisms that increase genetic information here.
http://www.talkorigins.org/indexcc/CB/CB102.html
Especially this part:
quote:
A mechanism which is likely to be particularly common for adding information is gene duplication, where a long stretch of DNA is copied, followed by point mutations which change one or both of the copies. Genetic sequencing has revealed several instances where this is likely the origin of some proteins. For example:
Two enzymes in the histidine biosynthesis pathway that are barrel-shaped, structural and sequence evidence suggests, were formed via gene duplication and fusion of two half-barrel ancestors [Lang et al. 2000].
RNASE1, a gene for a pancreatic enzyme, was duplicated, and in langur monkeys one of the copies mutated into RNASE1B, which works better in the more acidic small intestine of the langur. [Zhang et al. 2002]
Yeast was put in a medium with very little sugar. After 450 generations, hexose transport genes had duplicated several times, and some of the duplicated versions had mutated further. [Brown et al. 1998]
A PubMed search (at http://www.ncbi.nlm.nih.gov/entrez/query.fcgi) on "gene duplication" gives more than 3000 references to the biological literature.
The root of this link has a whole list of claims made by creationists, so this might be a handy database to start your search if you've got a new claim coming up.
Let me know if these links were of some help. If not, I'll be happy to look a little further. I'll still try to look up some good examples, the examples given above might be a little hard to understand.
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Tom
`Contrariwise,' continued Tweedledee, `if it was so, it might be; and if it were so, it would be; but as it isn't, it ain't. That's logic.'
-Through the Looking Glass by Lewis Caroll- |
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LOGOS
New Member
USA
10 Posts |
Posted - 04/29/2004 : 13:30:38 [Permalink]
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quote:
Originally posted by Ricky
You always here Creationists argue that evolution defies 2nd Law of Thermodynamics, how things go from disorganized to organzied in a system. Normally the evolutionists attacks how it defies the 2nd Law. However, I have never heard of the biological mechanism which increases the number of genes. Humans have a differnet number of genes than say a sponge right? How does this happen?
'Doesn't matter how. It makes no sense to try to argue with creationists using material reasoning and knowledge. Instead claim no knowledge at all and ask them to supply ANY evidence that (a) "god" spoke the universe into existence, and/or (b) "god" breathed life into dirt. They will not be able to produce anything, of course.
If the creationist insists that you explain 'xyz'; say "dunno!; But again, can you support the notion that "god" breathed life into dirt with evidence?"
Creationists invalidly try to perform an indirect proof, attacking the merit of the BBT or Evolution Theory, etc but since there are a myriad of claimed 'origin' theories, myths, fokelore, etc then even if they were 100% successful in discrediting Evolution Theory, this would do nothing as far as bolstering the idea of "god" breathing life into dirt.
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LOGOS |
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Ricky
SFN Die Hard
USA
4907 Posts |
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