sure, sounds reasonable enough to me.I kind of agree with that, but couldn't the pre-hominid who sharpened the first rock to make a cutting tool could be considered a trans-pre-hominid??
We evolved into humans and modern society because we figured out harness the resources around us. I think the author is getting more into changing our actual DNA structure and internal assimilation of man and machine. I think it's an evolutionary step beyond hominid into something else and that's why there is the "transhuman" title associated with this evolutionary step.
Trans-human is likened to the transitional phase into posthuman, from the way I read it.
protohuman --> human --> transhuman --> posthuman