By better kind of human, in my mind this is a human who's life has been lived out long from enhanced medicines and many of medical advancements. Not that age is the only factor, as we learn more about the brain, we could help children develop at a young age to be more active and well rounded human beings. The world requires forward thinking and positive people.
Progress requires creating a new and better kind of human in the case of each individual person. For humanity to progress, we need to give people a chance to be better on their own level. This cannot happen in group form. It involves changes in goal-setting, lifestyle, nutrition, and exercise.
Progress will happen, no matter what kind of humans there are. Each generation takes discoveries, inventions and ideas from previous generations and builds on them. Time does not stand still or go backward. Let the evolutionary process take care of creating a new and better kind of human. If we tried it, we don't know what we would get.
Progress does not require a new and better type of human. I think progress just means accepting when we were wrong in the past and moving on to a better future. It does not mean we have to change, just be sure to not cause future problems and learn from mistakes.
I do not believe progress requires the creating of a new and better kind of human. Doing this would probably cause us to back slide in many areas and would more than likely not lead to progress. Progress can be measured in many different ways and is, to some degree, subjective.