Kyo

Actually, I've been over the Prisoner's Dilemma quite a number of times - but always in a purely game theory context. I suppose this would be a case of me not being able to put two seemingly unrelated concepts together.

There are several points to make, however.
1) TIT FOR TAT does not take advantage of unresponsive strategies. For instance, if paired against a strategy that always cooperates, TIT FOR TAT will always score 3 points, when it could always defect and score 5. In real-world terms, I see this as being able to reliably 'dupe' the other party - something which corporations and governments are quite good at.
2) TIT FOR TAT also doesn't do very well against random strategies, because it inherently assumes that the other strategy is attempting to earn the most points. Humans are far from perfectly logical and are prone to indecision and random action.
3) TIT FOR TAT is also a victim of echo strategies. If you are paired with another TIT FOR TAT, except that it throws in a random defection, they will alternate between cooperate and defect forever - earning a lower average than the cooperation payoff (by alternating the 'sucker' payoff and the 'temptation' payoff)

To demonstrate a different point, however, consider Shubik's dollar auction. I have little doubt you've heard of it, but just in case, here are the rules:
a) A dollar bill is being auctioned, and will go to the highest bidder. Bids start at one cent, and each new bid must be higher than the previous one.
b) The second-highest bidder still has to pay - but for nothing!

This is obviously an extremely bad situtation to be caught in. Someone will obviously bid 1 cent. If you can get 99 cents of the deal, why not? But then, someone else thinks, "I could have that dollar for 2 cents." They bid 2 cents. But now the first bidder is in the unhappy position of paying 1 cent for nothing, so he bids 3 cents, etc. We keep going until the bid hits $1.00 even. But the previous bid was 99 cents. If he doesn't make a new bid, he will lose 99 cents. So he bids $1.01. And the game continues. Regardless of how high the number, the second-highest bidder will always be able to improve his position by almost a dollar by topping the current high bid.

This experiment was conducted at MIT, and it was found that a dollar could routinely be 'sold' for amounts much larger than a dollar - people were buying a dollar bill for $5!

Cooperation, in this case, would be to just let the first bidder take the dollar - for 1 cent. But that never happened.

The real-life analogy is 'investing too much to pull out.' Like waiting for hours in line for an amusement park ride, only to find out that part of the line was hidden and is actually twice as long as you thought it was. Or watching a movie that's terrible, but thinking you might as well finish it because you're almost done anyway. Television companies know about this syndrome, and tend to put more commercials near the end than at the beginning, because they know people are likely to want to finish the movie even if commercials are appearing at a rate of one after every scene.

On a different note, about spreading your seed rampantly - wild animals do it, and it seems to work for them. I don't know enough biology to form a more complex formulation, so if you can explain why it wouldn't have worked for humans, I'll take it at face value.