Dignity and Transhumanism

It would seem that transhumanism--roughly, the use of technology to fundamentally change our nature--poses some of the biggest current challenges to human dignity.  Whether it's the self-transformation of the person who calls himself "Cat Man" (Google him, it's rather disturbing) or suggestions about how to change human physiology and/or psychology to make us more adapted to a world facing rapid climate change, technology is being used or being proposed to be used in ways eerily similar to those anticipated nearly 100 years ago in Huxley's Brave New World.  To get discussion going on this issue, I propose the following scenario/question.  Suppose we developed the technology that would allow us to (d)evolve into seal-like creatures, similar to those in Kurt Vonnegut's novel Galapagos, and suppose the use of this technology were urged as a means to protect the environment from future human activities.  How should the resulting loss of human dignity figure in our decision-making about whether to proceed?