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Author Topic:   PROOF against evolution
sfs
Member (Idle past 2533 days)
Posts: 464
From: Cambridge, MA USA
Joined: 08-27-2003


Message 150 of 562 (78770)
01-15-2004 10:33 PM
Reply to: Message 149 by :æ:
01-15-2004 7:00 PM


quote:
The scientific method required repeatability of observations, not necessarily repeatability of the events observed.
Strictly speaking, science doesn't even need repeatability of observations, just that the observations be objective (i.e. visions and hunches do not count). Neutrinos coming from a supernova were observed in 1987, and have not been seen since (because there haven't been any supernovas close enough). Even without anyone being able to repeat those observations, they're still perfectly valid scientific data.
In general, telling scientists that they're not following the scientific method is likely to be a losing effort, since the practice of scientists is what defines the scientific method (which may only bear a loose resemblance to what's taught in ninth grade as the scientific method).

This message is a reply to:
 Message 149 by :æ:, posted 01-15-2004 7:00 PM :æ: has replied

Replies to this message:
 Message 160 by :æ:, posted 01-16-2004 11:53 AM sfs has not replied

sfs
Member (Idle past 2533 days)
Posts: 464
From: Cambridge, MA USA
Joined: 08-27-2003


Message 164 of 562 (79163)
01-17-2004 9:49 PM
Reply to: Message 163 by DNAunion
01-17-2004 11:00 AM


quote:
Also, technically, introns and exons related to RNA, not DNA.
I don't know how they were originally defined (since I have no formal training in genetics), but intron and exon are routinely used to describe DNA in current genetics literature.
quote:
However, I would like to ask a question. You seem to be claiming that the "98%" similarity between chimp and human DNA includes ALL of the DNA, including so-called junk DNA. I am not sure that is correct. For example, the value "98%" was quoted way before the HGP had completed, and I don't believe the chimp genome has been determined yet. I think the "98%" value is based primarily on protein-coding regions, and on a large number of genes, not all of them. For an explanatory example of the general method I think the number is based on...suppose scientists determined the sequences of just 1,000 protein-coding genes in humans and also the seqeuences of the same 1,000 genes in chimps, then compared them, finding that large sample of protein-coding genes to be "98%" identical in sequence. If this is the case, the junk DNA would not be involved in the calculation.
Anyone know the actual method?
The original measurement was done by hybridizing DNA from the two species and seeing how easily they annealed. More recently it has been confirmed by sequencing, first of ~1 Mb segments of genomic sequence (i.e. including everything, junk and all) and now of both entire genomes. The measured value from comparing the full human and chimp genomes is about 98.7% identity. (The chimp genome has been fully sequenced, and a draft is publicly available, but the paper hasn't been written yet, so that measurement isn't published yet.) So yes, the quoted value includes junk DNA. Identity is significantly higher in coding regions, although I don't know by how much.
These numbers can be a little misleading, however, since they describe only single-base-pair differences in homologous sequence. If you include insertions and deletions, the fraction of divergent bases will be much higher (perhaps 5%, but it hasn't been well measured yet).

This message is a reply to:
 Message 163 by DNAunion, posted 01-17-2004 11:00 AM DNAunion has not replied

sfs
Member (Idle past 2533 days)
Posts: 464
From: Cambridge, MA USA
Joined: 08-27-2003


Message 168 of 562 (79517)
01-19-2004 10:00 PM
Reply to: Message 166 by Mammuthus
01-19-2004 10:28 AM


quote:
re chimp-human sequence divergence, there was a recent paper that suggested a much higher divergence in sequences when indels are taken into account. This will have to be factored in once the chimp genome sequence is completed.
Proc Natl Acad Sci U S A. 2002 Oct 15; 99(21): 13633-5. Epub 2002 Oct 04. Related Articles, Links
Divergence between samples of chimpanzee and human DNA sequences is 5%, counting indels.
Yeah, that was the paper I was referring to when I mentioned indels. I was just too lazy to look it up.

This message is a reply to:
 Message 166 by Mammuthus, posted 01-19-2004 10:28 AM Mammuthus has not replied

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