Scientists, carrying out a study on eastern and western monarch butterflies, tried to prove that despite having different flying patterns, the two species are genetically the same.
Eastern monarch butterflies migrate from the US-Canadian border to central Mexico, covering nearly 3,000 miles. On the other hand, western monarchs fly to the Pacific Coast in winters, moving around 300 miles.
The study, led by biologists at Emory University, was published in the journal Molecular Ecology.
Senior author of the study Jaap de Roode found the results of the research surprising.
He added that it’s expected that organisms with different behaviors and ecologies would exhibit some genetic differences, but this did not turn out to be the case with eastern and western monarch butterflies.
Venkat Talla, the first author of the current study, investigated more than 20 million DNA mutations in 43 monarch genomes. He observed no genomic differences between the two species.
"Our work shows that the eastern and western monarchs are mating together and exchanging genetic material to a much greater extent than was previously realized," Talla stated.
He added that differences in their patterns of migration are likely due to the environment they live in.
The study revealed that after leaving their overwintering sites, monarchs travel north and lay eggs. The caterpillars develop into butterflies and move further. In this process, they mate and lay another generation of eggs.
The process continues until the days grow shorter and the temperature starts dipping. During this time, monarchs start their journey south.