Eciton army ants are a type of ant that can only travel on dry ground, due to their lack of wings. The study was conducted by sequencing DNA from different ants from Brazil to southern Mexico. This was done across nine different species of Eciton army ants. The similarities in their DNA sequencing proves that the ants crosses the region earlier than originally thought. This evidence was found by Moreau, an associate curator at the Field Museum in Chicago, by complete accident. The study was originally conducted to understand the diversity of army ants.
There is also geologic evidence that complements the evidence found by Moreau. Montes, a geologist of the University of the Andes in Bogota, Colombia. He has found the isthmus emerged around the same time by dating uranium preserved in rocks surrounding the connection.
Although it is thought that genetics helps us understand the future, like possible diseases and mutations, it can also help us understand the past, when combined with other research.