What's the difference between you and me?

[Mentat]

What is the exact percentage (in terms of genes? alleles? traits? ...I don't know) by which one human differs from another?

[Phobos]

Compared to each other, humans have a 99.9% similarity in genes of nuclear DNA.

[Njorl]

Originally posted by Phobos
Compared to each other, humans have a 99.9% similarity in genes of nuclear DNA.

Is that a little or a lot?

If I made 99.9% of my current salary I would be just as satisfied as I am now. If I detune my FM radio by 0.1%, I get no signal.

Njorl

[nautica]

Originally posted by Phobos
Compared to each other, humans have a 99.9% similarity in genes of nuclear DNA.

Compared with fruit flies we are 68%. Amazing.

Nautica

[iansmith]

Originally posted by Njorl
Is that a little or a lot?


0.1% is a lot because there is thousand of base pair per gene and we have between 40 000 to 60 000 genes. We got about 1 millions signigican base pair

0.1% of 1 million is 1 000 base pair that are different. The number migth not be high but one base pair change can change a whole gene.

[Monique]

Originally posted by Phobos
Compared to each other, humans have a 99.9% similarity in genes of nuclear DNA. Let's make that 99.998 percent or so. According to these (http://news.bbc.co.uk/1/hi/sci/tech/3042781.stm) scientists (they were my collegues :D) we share 99.4% of gene sequence with the chimp.

[Phobos]

Originally posted by Monique
Let's make that 99.998 percent or so. According to these (http://news.bbc.co.uk/1/hi/sci/tech/3042781.stm) scientists (they were my collegues :D) we share 99.4% of gene sequence with the chimp.

There seems to be a lot of variation in such estimates. From the articles I've seen over the past 8 years (I'm a data pack rat I guess), estimates for genetic similarities for humans to chimps have ranged from 95 to 99.4%.


I found 99.9% for human-to-human similarities cited from the Human Genome Project.
http://www.ornl.gov/sci/techresources/Human_Genome/project/info.shtml

[Phobos]

Originally posted by nautica
Compared with fruit flies we are 68%. Amazing.


Truly. Here are some other #'s I've collected from various sources...

human-chimp = 95 to 99.4%
human-African ape = 98%
human-gorilla = 97.7%
mice = 70 to 90% (I assume this wide range reflects old & new research)
fruit fly = 60%
nematode worm = over 33%
round worm = 20%

[Monique]

How about plants? :P

The reason that there is so much variation in the numbers, is the areas you are looking at. Coding region make proteins, which are very conserved. Non coding regions just in front of genes are regulatory and they will hold the secret of the difference between chimps and humans. Definition of such regulatory regions is very difficult, they are very ambiguous to predict, so researchers have focused on either analyzing the complete genomes or random collection of genes (like the one I cited).