Of course there’s an explanation (sperm like to develop at lower temperatures). But really: What intelligent designer could have come up with this?
It sounds as though Lents has never heard of the concept of “optimal”: best possible solution in given environment, as opposed to best theoretical solution as an abstraction.
The fact is that there is no good reason that sperm development has to work best at lower temperatures. It’s just a fluke, an example of poor design. If nature had an intelligent designer, he or she would have a lot to answer for. But since natural selection and other evolutionary forces are the true designers of our bodies, there is no one to question about this. We must interrogate ourselves: Why are we like this?
Oddly, in making such a dramatic claim (“there is no good reason that sperm development has to work best at lower temperatures”), Lents does not quote any expert on the subject of temperature and sperm development.
In addition to the obvious danger of designing such important organs without any protection or even padding, external testicles introduce additional problems for mammals. One in four men will develop a hernia in their groin, 10 times the rate of women, precisely because of a weakness in the abdominal wall left from the migration of the testicles out of the abdomen. Surgical repair is relatively straightforward, but surgery is a relatively new invention in the history of our species. While only a small percentage of these hernias become life-threatening, given how common they are, hernias have killed untold millions over the ages. More.
No wonder there is a mass panic about the worldwide shortage of births over the last century, resulting in mass depopulation, especially in the Third World…
Note: According to an online medical site re hernias, “In men, the incidence rises from 11 per 10,000 person-years, aged 16-24 years, to 200 per 10,000 person-years, aged 75 years or above.” (Jenkins JT, O’Dwyer PJ; Inguinal hernias. BMJ. 2008 Feb 2336(7638):269-72.) In short, hernias tend to be a problem for older men, as do heart attacks, strokes, and prostate cancer.
Everything starts to break down as we age… If we are going to talk about design at all, we can’t compare mortality in this world to immortality somewhere that can sustain it.
See also: At Skeptic: Five Questions about Human Errors for Proponents of Intelligent Design
Jonathan Wells on Lents’s claim that the human eye is wired backwards