Board Thread:Movie discussion/@comment-27198647-20151129152941/@comment-1259419-20170206234926

Mattwo wrote: Wouldn't that be more along the lines of hermaphroditism or [XY gonadal dysgenesis]? I was more thinkingof women with Androgen insensitivity syndrome (AIS). They are but have a Y-chromosome.

I think we should bring this discussion back to the main question: Why did InGen create female dinosaurs instead of males (which would never be able to lay eggs) to prevent reproduction? I'll summarize again.

Answer from film and novel:

In Michael Crichton's novel Henry Wu explains that animals start out as females and only one hormone causes it to become male. The hormone can be easily blocked. Part of this dialog is kept in the movie.

Is that scientifically correct?

In Nature (world-famous scientific journal) News I found this:

''For many years, scientists believed that female development was the default programme, and that male development was actively switched on by the presence of a particular gene on the Y chromosome. By the turn of the millennium, however, the idea of femaleness being a passive default option had been toppled by the discovery of...'' - Nature News: Sex redefined

In the 1980s, when Crichton wrote the Jurassic novel, it was not a strange idea. However, a few decades of scientific progress has invalidated this idea.

Even if the female gender was the default setting in humans, dinosaurs are not humans. It is unknown how sex was determined in dinosaurs. In cold blooded dinosaurs gender might have been determined by nest temperature (as in crocodiles) and in the warm blooded theropods it might have been genetic (as in birds),or a mix between the two.