Costa Rica: First Crocodile 'Virgin Birth' Recorded

Facts

• A crocodile has produced eggs despite the lack of a male mate in a very rare reproductive strategy known as facultative parthenogenesis (FP). The discovery by scientists was published Wednesday in the journal Biology Letters.¹
• The first recorded instance of a "virgin birth" among crocodiles occurred at a Costa Rican zoo, where a fully formed fetus was found inside one of several eggs laid in 2018 by an 18-year-old female — it was 99.9% genetically identical to its mother.²
• Although seven of the eggs were incubated by the park, none of them hatched. One, however, developed and contained a stillborn crocodile fetus.³
• Despite parthenogenesis previously being recorded in birds, lizards, snakes, and fish, it hasn't before been documented in crocodiles. FP research specialists behind the study said it suggested virgin births could be occurring in crocodiles without anyone noticing.³
• The discovery, according to researchers, suggests that evolutionary ancestors, including dinosaurs, might have been able to reproduce through FP, which happens under challenging conditions, such as when environmental stress or an absence of mating partners threatens a species.⁴
• Dr. Warren Booth of Virginia Tech in the US has said that the commonality of FP across "so many different species" points to the reproductive mechanism being "a very ancient trait that has been inherited throughout the ages."⁵

Sources: ¹Independent, ²The Telegraph, ³Sky News, ⁴Guardian, and ⁵BBC News.

Narratives

• Narrative A, as provided by Economist. This is a huge step forward for scientific discovery. Thanks to the research conducted in a Costa Rican zoo, more evidence has come to light for the commonality of FP across a broad range of species descended from dinosaurs. This development is an exciting moment for evolutionary biologists that could precipitate further documentation of the reproductive mechanism in reptiles such as turtles or chameleons.
• Narrative B, as provided by New York Times. Despite the orthodox perception of zoos as protecting and preserving exotic and under-threat species, the observation of FP in a crocodile kept in isolation for so many years demonstrates the stresses artificially confining animals can provoke. It's unnatural for animals to spend their lives in captivity, and this latest discovery should raise the question of whether these types of institutions should even exist.