Twins are a somewhat common occurrence: they make up about 1.9% of the global population, and the odds of a parent giving birth to twins is around 1 in every 285 pregnancies. While one may think the odds are universal around the world, this isn’t quite the case. Thanks to the phenomenon known as founder effect, certain genetically-isolated populations may by chance carry traits not typically seen in the at-large population. For example, if a very small group of people inaugurates a new colony, and some members just happen at random to carry the genetic trait for multiple birth, that trait may get passed on down to future generations. If little or no immigration into the colony occurs and colony members interbreed only with one another, then that genetic trait will be repeated much more frequently and disproportionately to the at-large population elsewhere. Such is the case in a small German-Brazilian community near the Argentine border.
Cândido Godói is known as the ‘Land of Twins’ (Terra dos Gêmeos in Portuguese) for good reason. Ten percent of the municipality’s population are of twin births, reaching an absurd level in the neighbourhood of Linha São Pedro (St. Peter’s Line), where 80 households are home to 44 pairs of twins. The explanation, as hinted at above, is rather simple: a smaller founder population that just happened to carry a slightly higher-than-average predisposition toward twin births (in the case, a group of eight families of German ancestry) settled in a somewhat isolated area (northwestern Rio Grande do Sul) and interbred with one another with little genetic contribution from outsiders, allowing the multiple birth trait to increase in frequency as it was shared among the offspring of the community.
Evidently, just having an abnormal amount of twin births wasn’t spectacular enough for some conspiracy theorists trying to find a more glamorous explanation. There is a rather pervasive myth that Cândido Godói was the site of a human genetics experiment conducted by the notorious World War II physician/war criminal Josef Mengele sometime after he escaped to South America in 1949. Indeed, a quick Google search for ‘”candido godoi” mengele’ produces an astonishing 38,000 results. The New York Times even picked up the story and ran with it, as did the Telegraph, all based on the research of an Argentine writer conveniently plugging a Mengele biography (‘They’re blond German twins! People kind of recognise Mengele from a picture! It must be him! Buy my book!’). Of course, this completely ignores the fact that baptismal records show the twin phenomenon occurring in Cândido Godói pretty much since the founding of the community, decades before the infamous doctor arrived in the area. National Geographic even went so far as to film an episode of its documentary series Explorer in the town in order to debunk the Mengele myth.
Regardless of the negative publicity of the past two years thanks to the Mengele debacle, the town embraces its twin predisposition with open arms; the city even lists the ‘Phenomenon of the Twins’ as its top attraction, holds a twin festival every year, and uses an image of two faces as a municipal marketing logo. Hopefully this community will be able to live down this recent media outburst and get back to life as normal (well, as normal as life is in a town full of twins).
Handwerk, B. (2009). “Nazi Twins” a Myth: Mengele Not Behind Brazil Boom? National Geographic News, 25 November 2009. Avaiable at http://news.nationalgeographic.com/news/2009/11/091125-nazi-twins-brazil-mengele.html. Accessed 29 July 2010.
Matte, U. et al. (1996). Study on possible increase in twinning rate at a small village in south Brazil. Acta geneticae medicae et gemellologiae 45(4): 431-437. Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/9181177.
Segal, N.L. (2009). The Birth of Octuplets: A Research Puzzle / Twin Research Reviews: Natural Twinning Rate; Survival at, or Before, Thirty Weeks Gestation; Unique Mirror-Imaging Effects / News Highlights: Twin Robbery at KaDeWe?; Twins Born Together and Apart; Twinning Rates in Candido Godoi. Twin Research and Human Genetics 12(3): 328-331. Available at http://www.atypon-link.com/AAP/doi/abs/10.1375/twin.12.3.328.