Humans can be up to 10% different genetically?

Dustin Kesselberg

Illuminator
D
Joined
Nov 30, 2004
Messages
4,669
I read an article that stated that new studies into the human genome have found that the variability can be as much as 10% between some humans. 10% difference? How can this be possible if humans and chimps are 98% similar?

Any ideas?


http://www.scenta.co.uk/scenta/news.cfm?cit_id=1315659&FAArea1=widgets.content_view_1

http://www.innovations-report.de/html/berichte/biowissenschaften_chemie/bericht-74704.html

http://www.boston.com/news/nation/articles/2006/11/23/new_dna_map_shows_more_gene_variations/
 
I think some facts may be getting mixed up here, but the same recent articles have pointed out that humans and non-human chimps are more genetically different than each other than previously thought.
 
My ignorance may be showing but isn't there a difference between the genes that decide the color of your eyes and the genes that decide if you have two legs and two arms? I mean, there are many, many different eye colors out there but very, very few variations on the number of arms and legs.
 
Well, I make twenty million divided by three billion 0.66%, but then I'm just a mathematician and not a bleedin' journalist.
 
Dustin said:
I read an article that stated that new studies into the human genome have found that the variability can be as much as 10% between some humans. 10% difference? How can this be possible if humans and chimps are 98% similar?

Any ideas?
Click to expand...

Here's a DNA sequence

ACTGTGACAG

Here's another

ATTGTGACAG


Let's say that a 'gene' is represented by 5 letters i.e. ACTGT is a 'gene'. so each sequence here is made up of two genes.[In reality, there are several hundred bases per gene, but the principle's the same.]

At the base (letter) level the two sequences are 90% identical; only one of the ten letters is different.

At the gene level the first gene is different between the sequences, the second is the same in both sequences, so they're 50% identical.

The measure of similarity you get depends on what resolution you use to examine the sequence. The human-chimp comparison is normally quoted at the letter-level, and intra-species comparisons at the gene level.

The new research indicates that gene duplication is a more important source of variation than previously thought.

So a sequence like

ATTGTATTGTGACAG

can crop up, where a gene is repeated. It's not always obvious how to find these duplications or count how 'different' they are from a non-duplicated version; but however they've done it, the 10% figure isn't directly comparable with the human-chimp value.

[This is obviously highly simplified, but I hope it helps.]
 
There appears to be a difference in the number of copies of certain genes, perhaps as many as 10% of them.

~~ Paul

Edited to add: What Sphenisc said.
 
sphenisc said:
The measure of similarity you get depends on what resolution you use to examine the sequence. The human-chimp comparison is normally quoted at the letter-level, and intra-species comparisons at the gene level.
Click to expand...
Good point from sphenisc. It depends what you're counting: nucleotides, amino acids, codons, proteins, or genes. (I think I've arranged that list in decreasing order of proportion of similarity, but I have a headache coming on.)

If you're looking at genes which are absolutely identical, then the difference between chimps and humans is 71% (with a mean difference of 2 nucleotides per gene). If that's what they're counting, then 10% difference between humans and other humans isn't so silly.

If you count nucleotides, then from the figures given, the difference betwen humans and other humans is 0.6%, and between humans and chimps is 4%.
 
Last edited:
Dave1001 said:
Dubya jokes aside, there are arguably about 6 billion.
Click to expand...

would those making that argument (you?) suggest changing the definitions of both human and chimp? It seems strange to make an argument for the reclassification of chimp under the homo genus in a thread which suggests a greater genetic diversity between the species (H sapiens and Pan paniscus/troglodytes)than previously thought. Even then, i'm not sure why someone would want to use the term "human chimp" - if chimps were homo, and "humans" taken to mean members of the homo genus (rather than as is often the case, of the species H.sapiens), then there would be no merit in using the label "human chimp" when talking about H. sap sapiens.
 
Last edited:
andyandy said:
would those making that argument (you?) suggest changing the definitions of both human and chimp? It seems strange to make an argument for the reclassification of chimp under the homo genus in a thread which suggests a greater genetic diversity between the species (H sapiens and Pan paniscus/troglodytes)than previously thought. Even then, i'm not sure why someone would want to use the term "human chimp" - if chimps were homo, and "humans" taken to mean members of the homo genus (rather than as is often the case, of the species H.sapiens), then there would be no merit in using the label "human chimp" when talking about H. sap sapiens.
Click to expand...

under tis approach one could as easily consider the genus homo to = chimp, of which there would be three taxanomic groupings, one which would be humans (sapiens), and the others troglodytes (common chimps) and bonobos.

http://news.bbc.co.uk/2/hi/science/nature/3042781.stm
 
Dave1001 said:
under tis approach one could as easily consider the genus homo to = chimp, of which there would be three taxanomic groupings, one which would be humans (sapiens), and the others troglodytes (common chimps) and bonobos.

http://news.bbc.co.uk/2/hi/science/nature/3042781.stm
Click to expand...



Your suggesting that the term "chimp" (used for the two species Pan troglodytes and Pan paniscus) should be redefined as a genus description and used interchangably with "homo"???

The linked article (refering to a 99.4% similarity that this new reseach challenges) states that some researchers believe that the chimp species should be moved under the homo genus - not that they believe that "chimp" should be the new genus term.....

for a guy who purports to have a bio-medical degree you seem a little rusty on your biological classifications.....
 
andyandy said:
Your suggesting that the term "chimp" (used for the two species Pan troglodytes and Pan paniscus) should be redefined as a genus description and used interchangably with "homo"???

The linked article (refering to a 99.4% similarity that this new reseach challenges) states that some researchers believe that the chimp species should be moved under the homo genus - not that they believe that "chimp" should be the new genus term.....

for a guy who purports to have a bio-medical degree you seem a little rusty on your biological classifications.....
Click to expand...

I replying on good faith that you're not just arguing to argue here. My point in response to your earlier post is if common troglodytes, sapiens, and bonobos were to all be classified in the same genus, as some advocate, it's rather arbitrary if the informal name someone uses for the genus is "chimp" or "human". If the informal name one chooses is chimp, then it's reasonable to say in an informal way that there are about 6 billion human chimps.

As for the ad hominem you ended with, rather than racing you to the bottom with personal attacks, I'm reporting your post.
 
The human genome has ~3 billion base pairs.

We differ from each other by ~ 3 million base pairs.

Any two people on the planet except identical twins have the same average number of differences in our DNA base pairs regardless of how closely or distant we are related including those that appear to be of a different race or those that are directly related to us.

~85% of the variation (IE 85% of the base pairs that are unique to a person) can be found within a small group of people. In other words, while we all differ a little, if you put a small group of people together you will find 85% of all the variations in base pairs between humans are going to be in that group.

My source is a lecture given by Mary-Claire King a genetic researcher at the U of W. If you have an hour, it is an excellent discussion on the nature of the one human race we all belong to.

http://www.uwtv.org/programs/displayevent.aspx?rID=2493&fID=1473
Genomic Views of Human History
New tools of genomic analysis are being used to shed light on historical puzzles. Migrations of ancient peoples, the effects of geographic boundaries on human movements, origins of ethnic groups, and racial differences are now the focus of integrated analysis by historians, anthropologists and geneticists. "When people move, they take their genes along and pass them on to their descendants in their new homes," Dr. Mary-Claire King states. "Thus, every present-day population retains clues to its ancient roots. Common ancestries can be confirmed and human migrations traced by comparing DNA sequences of present-day populations."
Click to expand...
 
Dustin said:
I read an article that stated that new studies into the human genome have found that the variability can be as much as 10% between some humans. 10% difference? How can this be possible if humans and chimps are 98% similar?

Any ideas?


http://www.scenta.co.uk/scenta/news.cfm?cit_id=1315659&FAArea1=widgets.content_view_1

http://www.innovations-report.de/html/berichte/biowissenschaften_chemie/bericht-74704.html

http://www.boston.com/news/nation/articles/2006/11/23/new_dna_map_shows_more_gene_variations/
Click to expand...

I'll wait for confirmation and a better understanding of what these findings mean and the significance of CNVs before changing my previous information. It seems to contradict a lot of previous research and the summaries in these news reports are inadequate. They don't say enough about the quality of the differences nor how the previous conclusions were obtained and why these findings differ so much.
 
Last edited:
andyandy said:
for a guy who purports to have a bio-medical degree you seem a little rusty on your biological classifications.....
Click to expand...

Actually, in my time that would have been true because a lot of time was spent on classification (Bio B.S. in '68) BUT, by then the move was already towards cellular and genes as the primary emphasis and that continued apace. At this point , only specialists are heavily into classification - bio-medical would be emphasizing genetics/cellular physiology.:) :)
 
Dave1001 said:
I replying on good faith that you're not just arguing to argue here. My point in response to your earlier post is if common troglodytes, sapiens, and bonobos were to all be classified in the same genus, as some advocate, it's rather arbitrary if the informal name someone uses for the genus is "chimp" or "human". If the informal name one chooses is chimp, then it's reasonable to say in an informal way that there are about 6 billion human chimps.
Click to expand...

so we should ensure that "humans" is understood as refering solely to the species H.sapiens and not the homo genus, shift Pan troglodytes and Pan paniscus to under the same genus as H.sapiens, and call that genus "chimp," rather than "homo" ......and do all this so that we can use the term "human chimp"

ok........:D

As for the ad hominem you ended with, rather than racing you to the bottom with personal attacks, I'm reporting your post.
Click to expand...

You do seem to report a lot of people for incivility - maybe give the mods a break sometime.......or maybe you could just try to stop being quite so thin skinned :)
 
andyandy said:
You do seem to report a lot of people for incivility - maybe give the mods a break sometime.......or maybe you could just try to stop being quite so thin skinned :)
Click to expand...

Also reported. I'd rather report uncivil posts by you than exchange insults or ad hominems.
 
fuelair said:
Actually, in my time that would have been true because a lot of time was spent on classification (Bio B.S. in '68) BUT, by then the move was already towards cellular and genes as the primary emphasis and that continued apace. At this point , only specialists are heavily into classification - bio-medical would be emphasizing genetics/cellular physiology.:) :)
Click to expand...
I have to agree with this. I conduct "biomedical research" and by all accounts could be considered a biomedical engineer as much as a chemical engineer. But I have NO CLUE about the proper classification of species. Just not something I ever had to do.

But it is good to have those who are knowledgable about this keep those of us who aren't in line. But please, be gentle.:o :)
 
You must log in or register to reply here.

Back
Top Bottom