Other opponents of directed evolution extend the argument further. They acknowledge that post-humans may be capable of claiming the same natural rights as humans by virtue of their capacities, but argue that creating such a species would challenge the notion that being human is sufficient for claiming those rights, in the same ways that discovering rational extraterrestrials would. This, in turn, would potentially disenfranchise the humans, like infants or the mentally disabled, who cannot show adequate functional capacities to qualify for equivalent species-neutral moral status. At the same time, they argue, if the post-humans actually have expanded capacities, they may claim natural rights to a proportionately expanded range of opportunities and freedoms, beyond those to which normal humans are entitled. This runs the risk of creating the kinds of oppressive hierarchical society against which human rights are supposed to be the antidote, and, potentially, to the return of coercive eugenic programs aimed at the eventual extinction of the human species (Fukuyama, 2002; Mehlman, 2012). 