Kromosomfel

Malcolm: How do you know they can't breed? 

Wu: Well, because all the animals in Jurassic Park are female. We've engineered them that way. 

Malcolm: But again, how do you know they're all female? Does somebody go out into the park and pull up the dinosaurs' skirts?

Wu: We control their chromosomes. It's really not that difficult. All vertebrate embryos are inherently female anyway, they just require an extra hormone given at the right developmental stage to make them male. We simply deny them that.

- Jurassic Park (1993)

Inte för att filmer behöver vara vetenskapligt korrekta. Och inte för att JP hör till den hyperrealistiska genren alla gånger... Men den får mycket annat rätt som inte alls var självklart när den gjordes, som dinosauriernas släktskap med fåglar eller att de framställs som varmblodiga. Därför var det var lite jobbigt att konstatera att filmen förmedlade en felaktig uppgift i den här stilen.

... The fact that all vertebrate embryos are NOT inherently female at all. Many vertebrates do indeed have an XY sex determination system – H. sapiens among them – wherein the female is the homogamete (XX) and the male the heterogamete (XY). Briefly, “maleness” is conferred by the Y-chromosome (in therian mammals, there is a specific sex-determining region), and its absence results in female offspring; as embryos, they are “inherently female”, if you like. However, there are also vertebrates that have a ZW sex determination system, wherein the male is homogametic (ZZ), and the female heterogametic (ZW). This arrangement is found in a variety of vertebrates: some insects, amphibians and reptiles – and in all birds.

Elizabeth A. Kingsley på hemsidan (bloggen?) And you call yourself a scientist! levererar Jurassic Park (1993),  en lång beskrivning där filmens vetenskaplighet med mera dissekeras på längden och tvären.