In the past, aging was caused by free radicals in the human body, and antioxidants can destroy these free radicals, thereby preventing aging. However, a recent study compared the genetically modified nematodes that can "kill" free radicals with normal nematodes It is found that there is no difference in aging and life span between the two. Therefore, it can be considered that antioxidants have no effect on human health. Which of the following cannot weaken this conclusion? ['The aging mechanism of nematodes is essentially different from the aging mechanism of humans.', 'Nematodes have many of the same genes as humans.', 'The effect of genetic modification on nematode lifespan offsets the effect of "eliminating" excess free radicals on nematode lifespan.', 'Another study found that although antioxidants can not resist aging, they can speed up the recovery of damaged cells.']