Historical Mammal Extinction on Christmas Island (Indian Ocean) Correlates with Introduced Infectious Disease
2008

Extinction of the Christmas Island Rat Linked to Disease

Sample size: 21 publication Evidence: high

Author Information

Author(s): Wyatt Kelly B., Campos Paula F., Gilbert M. Thomas P., Kolokotronis Sergios-Orestis, Hynes Wayne H., DeSalle Rob, Daszak Peter, MacPhee Ross D. E., Greenwood Alex D.

Primary Institution: Old Dominion University

Hypothesis

Did introduced infectious diseases contribute to the extinction of the Christmas Island rat?

Conclusion

The study provides molecular evidence that a pathogen, Trypanosoma lewisi, emerged in the Christmas Island rat population just before their extinction.

Supporting Evidence

  • The study found trypanosome DNA in both endemic and invasive rat species.
  • Endemic rats collected before the introduction of black rats showed no signs of trypanosome infection.
  • Hybridization between endemic and black rats was not supported by genetic evidence.

Takeaway

Scientists found that a disease from introduced rats likely made the native Christmas Island rats sick, leading to their extinction.

Methodology

The study used ancient DNA methods to analyze museum specimens of rats collected during the extinction period.

Limitations

The study was limited by the small number of available specimens and historical records.

Digital Object Identifier (DOI)

10.1371/journal.pone.0003602

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