Don't reply to your own post, blah blah. BBC News covered this in a far less misleading manner and the numbers they quote are in line with my calculations.
I'm no expert in this *biology* or *math* thing (anymore), but the poster is misleading, if not wrong. Regardless, they failed at their math. If you observe 12 changes in a sequence 10,149,085 nucleotides in length, then your mutation rate is 12/10149085. Follow? Ok, now here is the big leap: The size of the human genome is 3.25x10^9. That is
3,250,000,000 which the observant will notice is a larger number than 10,149,085. At this point we should be thinking, are we really comparing 12 to 150? It's not as straightforward as all that, and I suppose you can't blame the poster for not mentioning a couple nuances...
If you project the mutation rate on the size of the human genome, sort of like this guy we know (Haldane), you might notice that we expect that maybe there would be 3840 changes. Forgive the massive oversimplification, but trust that this is totally in the spirit of the original. Now, there has been about 7.3 generations. So if we take the "distance" you have to travel from each to get back to the common ancestor, that's roughly 15 (7.3 x 2 and round up for some padding). So with 3840 mutations / 15 generations we end up with about 260 expected mutations per generation. This is about twice the 150 Haldane expected, but considering the tech they had in 1935, that's not too far off is it? So, are we talking 260 vs 150, or 12 vs 150?
Moral: Whenever you read stories where math and biology overlap, do the math yourself before you start. Chances are that they didn't.
By the way, I used Wolfram Alpha for the definition of "size of the human genome" and "average length of a generation".
Just change your DNS servers to OpenDNS (http://www.opendns.com/) and register your IP with them. You can use their category-based filtering to block the pr0n. Block adware, malware, and phishing while you're at it. Oh, and enjoy a faster DNS service and extensive stats pages. If you are worried about a dynamic IP from your ISP, don't be: most ISP's preferentially reassign IPs to customers instead of switching it up. Happy censoring!
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Don't reply to your own post, blah blah. BBC News covered this in a far less misleading manner and the numbers they quote are in line with my calculations.
I'm no expert in this *biology* or *math* thing (anymore), but the poster is misleading, if not wrong. Regardless, they failed at their math. If you observe 12 changes in a sequence 10,149,085 nucleotides in length, then your mutation rate is 12/10149085. Follow? Ok, now here is the big leap: The size of the human genome is 3.25x10^9. That is 3,250,000,000 which the observant will notice is a larger number than 10,149,085. At this point we should be thinking, are we really comparing 12 to 150? It's not as straightforward as all that, and I suppose you can't blame the poster for not mentioning a couple nuances...
If you project the mutation rate on the size of the human genome, sort of like this guy we know (Haldane), you might notice that we expect that maybe there would be 3840 changes. Forgive the massive oversimplification, but trust that this is totally in the spirit of the original. Now, there has been about 7.3 generations. So if we take the "distance" you have to travel from each to get back to the common ancestor, that's roughly 15 (7.3 x 2 and round up for some padding). So with 3840 mutations / 15 generations we end up with about 260 expected mutations per generation. This is about twice the 150 Haldane expected, but considering the tech they had in 1935, that's not too far off is it? So, are we talking 260 vs 150, or 12 vs 150?
Moral: Whenever you read stories where math and biology overlap, do the math yourself before you start. Chances are that they didn't.
By the way, I used Wolfram Alpha for the definition of "size of the human genome" and "average length of a generation".
Just change your DNS servers to OpenDNS (http://www.opendns.com/) and register your IP with them. You can use their category-based filtering to block the pr0n. Block adware, malware, and phishing while you're at it. Oh, and enjoy a faster DNS service and extensive stats pages. If you are worried about a dynamic IP from your ISP, don't be: most ISP's preferentially reassign IPs to customers instead of switching it up. Happy censoring!