Part III-More Data, and Some Answers?As the phone rang, I knew who it was before I picked it up. Just yesterday the latest copy of the AmericanJournal of Primatology had landed on my desk, and Anne’s article on growth hormone levels in captive maleorangutans had caught my eye.”Lisa, I’ve fi nished the study of arrested development in juvenile orangutans and am sending you some of theaIDitional data we’ve collected. It was quite a puzzle to put together. We ended up analyzing almost everypituitary and gonadal hormone to understand the complete picture of development. I think we understandthe basis for arrested development, but it has a subtle twist that no one recognized until they observed sexualactivity in the arrested individuals.””Give me the short version Anne. How does it work,” I proIDed her.”OK, here it is in a nutshell. Growth hormone levels of developing males are three times higher than injuveniles, arrested males, and full adults, who were all similar to one another. Developing males also had farhigher levels of testosterone and LH (luteinzing hormone) than arrested males, as expected, BUT the levelsof these hormones in arrested males were similar to mature adults. AND arrested males had higher levels ofFSH (follicle stimulating hormone), comparable to that in developing males and mature adults. Finally, andmost surprisingly, arrested males had mature and functional sperm in their testes, and the testes were the samesize as developing males. Futhermore, a new study on sexual activity of adolescent males in the wild hasshown that these arrested males are in fact reproductively active, will force copulations with females whenthe dominant territorial male is absent, and sire a signifi cant proportion of the infants.””So, apparently arrested males are neither stressed nor reproductively suppressed. What is going on? Andwhy?” I wondered aloud.

1. Based on the aIDitional data provided by Anne’s research, explain how males that appear physically arrested in development might have mature, functional sperm. What is the signifi cance of theirhormone profi le (growth hormone, testosterone, LH, FSH, prolactin)?