I suspect, though, that genes and the absence of a father reinforce each other in this regard.

The problem is they’ve essentially selected the kids who’ve had sex early and biased their sample. When the kids who are currently virgins start to have sex, then the average age of first intercourse for kids in families where the father was always present will likely go up more than the others since they represent 79% of the individuals in that group. This could potentially produce the opposite conclusion.

So correct me if I’ve missed something, but I don’t think they can justifiably conclude from this that genes are more important than the presence of a father.

Then the second set of statistics found that the average age of first intercourse was 15.28, 15.36, and 16.11 for children whose fathers were absent, sometimes absent, and always present, respectively. You cannot use an unknown value when calculating averages. The second set of statistics therefore cannot include the children who did not have sex as measured by the first statistic, since one cannot assume when they will have sex.

I guess my secondary-school level sciences must be rusty, but I always understood that, evolutionarily speaking, monogamy was the optimum means a male human can employ to ensure that his genes are passed on.

As I understood it, that is why, in primitive, polyamorous/polyandrous societies, the avuncular relationship is so important. A man could not know for certain who his children are he is not the only one having intercourse with a woman. So, he latches on to his sister’s children, as the next best way to ensure his genes progress.

At any rate, the Christian theologian doesn’t necessarily need to disagree with modern science. Yes, some evolutionary advantages and genetic factors might be contradictory to Christian morality, but that doesn’t somehow “disprove” said morality. If anything, it further bolsters the idea that said morality developed independant of humans. It accentuates the divinity of said morality, rather than diminish it.

Of the seven deadly sins, there is a simple evolutionary explanation for why five of them would be of reprodutive advantage in a prehistoric civilisation. Humans may like to think of themselves sometimes as packages of logic without connections to primative nature, but they are still animals, loaded with all the instincts needed to be a skilled breeder in a tribe of apes.

The only reason sex is so popular is that humans, and every other sexual organism on this planet, come genetically programmed to want it and to seek it. That’s just basic secondry-school level natural selection: The more sex someone had (prior to reliable contraception), the more offspring they have to carry those sex-seeking genes.