竟然从一篇发表在PNAS上的文章中挑出错误

I can't belive myself that I have found a mistake in a paper published in PNAS[ Proceedings of the National Academy of Sciences ] ! The following is the correspondent author's reply after I send a email to him:

Dear Qian,
Many thanks for your email - you are correct, we have mentioned the wrong diet in the text. We should have said the 19:33 diet not the 30:22 diet. Focus on the diamond symbols (both open and closed) and see how they shift to the left along the x-axis from generation 4-8. The square symbols (30:22) move down from generations 1-4 but not from 4 to 8. However, the general point is the same (the statistical test mentioned was based on all diets) - there is a decline in consumption which is unrelated to selection regime.Well spotted!Yours ever,Steve This indicates a decline in consumption of the 30:22 diet, but since the decline was similar for both selection regimes (high-carb and high-protein), it is unrelated to At 21:56 11/10/2006, you wrote:
Dear Prof. **,
I'm a graduate student majored in Plant protection from Nanjing Agricultural University, Nanjing, Jiangsu Province, PR of China. I apologize for my disturbing you, because when I read your paper "***" published in PNAS ,September 19, 2006 ** I find myself can't follow with you about the result of Shift in Lipid Deposition on Artificial Diet Regimes in the last two sentences--" In particular, there was a pronounced reduction from generation four to eight in the amount eaten of the P/C of 30:22 diet (Fig. 1 B vs.C). However, this pattern occurred in both selection regimes:hence, it apparently was unrelated to changes in lipid accumulation in response to dietary regime (interaction term regime by test diet: F4,60 = 2.16, P = 0.085; regime by generation by test diet: F8,60= 1.30, P= 0.261)."
I'm confused about the pronounced reduction: if it refers to the amount eaten of the P/C of 30:22 diet (Fig. 1 B vs.C), but there seems to be a slight increase of the high-protein selected regime (open square) inconsistent with the description; however, if it can be regarded as the pupal lipid content (intuitively from the figure 1C, dashed lines) there is also conflict with high-protein regime(solid line). Would you explain it to me in your convenient time? I will appreciate your reply and assistant!
Yours,
Qian,**