Seems to me that this is the standard communication problem that results fom two different worldviews. The philosophical one doesn't really care about 'how' but wants to answer 'why' and the scientific one keeps explaining 'how' but doesn't really care so much about 'why' .
S&R has put together a superb scientific response (how) while Perry seems to be saying that the 'how' cannot explain the 'why' and is therefore deficient. The 'why' is of course speculative and so we get opinion but no substance as the 'why' has no explanatory power as to 'how' (the bible doesn't contain information on genetics for example.) Those seeking 'how' answers normally detest opinion based 'why' answers and those seeking 'why' answers cannot always fathom what is so special with 'how' answers and get frustrated when a 'how' contradicts an expected evidence for a 'why'. This paragraph will now explode as it is too horrible to read again.
Philosophers and lovers of why - you would do well to ask yourself if the how answers given here are really at odds with your decided why and then a lot of misguided attacks on the world of how knowledge can be avoided.
Scientists and lovers of how - thank you.