European colonisation of South America resulted in a dramatic shift from a native American population to a largely mixed one, a genetic study has shown.
It suggests male European settlers mated with native and African women, and slaughtered the men.
But it adds that areas like Mexico City “still preserve the genetic heritage” because these areas had a high number of natives at the time of colonisation.
The findings appear in the journal Public Library of Science Genetics.
The international team of researchers wrote: “The history of Latin America has entailed a complex process of population mixture between natives and recent immigrants across a vast geographic region.
“Few details are known about this process or about how it shaped the genetic make-up of Latin American populations.”
The study examined 249 unrelated individuals from 13 Mestizo populations (people from a mixed European/native American origin) in seven countries, ranging from Chile in the south to Mexico in the north.
“There is a clear genetic signature,” explained lead author Andres Luiz-Linares from University College London.
“The initial mixing occurred predominately between immigrant and European men and native and African women.”
He said that the study showed that it was a pattern that was uniform across Latin America.
“We see it in all the populations we examined, so it is clearly a historical fact that the ancestors of these populations can be traced to matings between immigrant men and native and African women.”
The researchers found that within the genetic landscape of Latin America, there were variations.
“The Mestizo with the highest native ancestry are in areas which historically have had relatively large native populations,” they reported.
This included Andean regions and cities such as Mexico City, where major civilisations were already established by the time Europeans reached the continent in the late 15th Century.
“By contrast, the Mestizo with the highest European ancestry are from areas with relatively low pre-Columbian native population density and where the current native population is sparse,” they added.
Explaining the fate of native males when the Europeans arrived, Professor Luiz-Linares said: “It is a very sad and terrible historical fact, they were basically annihilated.
“Not only did the European settlers take away land and property, they also took away the women and, as much as possible, they exterminated the men.”
He said the findings could help people change their perception of Latin American history.
“It is very important in terms of rescuing the past and recognising the roots of the population, and the living presence of natives within the current population,” Professor Luiz-Linares explained.
As well as providing an insight into the past, the team hopes that the findings will also help shape studies aimed at identifying and analysing diseases.