'aided natural selection' what are you on about? Making fire is like making tools, making clothes, making weapons, making and setting traps, storing water in gourds, firing bows and throwing spears; as well as ability to use language, ability to trade, and to get on well with a group . People who weren't capable of doing these kinds of things would not have done very well at passing on their genes...
Tyler is talking specifically about natural selection for physical prowess.
Using fire, tools, weapons, clothes etc have allowed less physically able individuals to survive, yes... But it also favoured those who were better able to use these things - better mentally able. It was still natural selection, just for things more and more relating to the brain over the rest of the body.
Of course, civilisation allows people to survive who are neither physically nor mentally able, but that's a different matter.
No, I was not just talking about natural selection in terms of physical characteristics, but mental characteristics as well.
The above examples are dud, these days. Setting traps is a skill most people in the developed world would be hopeless at, for example. Modern technology allows one to circumvent the need to get along in a group - for example, those who have inherited wealth have no real need to "get along" with others as they can pay people to do what they want - the Internet also helps avoid interaction. Storing gourds, firing bows, throwing spears are also meaningless, nowadays. Indeed, one could argue that, even in ancient times, they did not help reproductive success. I mean, the chiefs of tribes generally did not fight or do manual labour, yet had far more wives/mistresses on average than other men, and so had more children than the latter, and were more likely to survive since they were non-combatants.
Besides, what you are talking about is technology, and to a lesser extent culture(re mention of clothes/fire/weapons etc.) which is, of course, quite separate from physical characteristics.
Indeed, culture also ruins natural selection, just like technology. For example, all political philosophies try to socially engineer humans to be different from what they naturally are. Egalitarianism is the worst example thereof in terms of ruining natural selection, but the other ideologies all are unnatural, too. Eyeglasses, a common aspect of technology, notoriously make peoples' eyesight worse. Watching TV notoriously makes small children unable to concentrate and learn properly. And so on and so forth...
Indeed, the clincher is that modern culture/technology does not just allow those to breed who in previous times would have been far too physically and mentally unfit to breed, but it also makes it more difficult for the more intelligent to breed. It is a notorious fact that the more intelligent a person is, nowadays, the fewer children he or she will have. Education also lowers reproductive success since people , as a result, put off having children until later, plus they are more likely to have been taught about birth-control. PHDs have the least number of children, for example.