Biology

Genetics or Evolution

In the article How the Butterflies got their Spots (2010), it talks about how scientists at Cambridge have found "hotspots" in butterflies' genes that they believe will explain one of the most extraordinary examples of mimicry in the natural world. They believe that their discovery will explain the phenomenon of how two butterfly species have evolved exactly the same striking wing color and pattern.

Heliconius, or passion-vine butterflies, live in the Americas and although they cannot interbreed, H. melpomene and H. erato have evolved to mimic one another perfectly. These butterflies have splashes of red and yellow on their black wings that signal to birds that they contain toxins and are extremely unpleasant. These two butterflies mimic one another's color and pattern in order to reinforce these warning signals.

A team of researchers from UK and U.S. universities led by experts from Cambridge, have been breeding the butterflies in Panama for the past decade, and have been searching for the genes responsible for the butterflies' wing patterns and the answer to the question of whether the same genes in two different species are responsible for the mimicry.

For many years, scientists have considered whether when different species evolve to look the same if they do indeed share a common genetic mechanism. The researchers have found it interesting because it tells about how flexible evolution is. If the same wing pattern evolves independently in different populations then it is expected that the same genes are not involved.

Due to the fact that butterflies have thousands of genes in their genome, most scientists felt it was unlikely that the same genes would be involved, but the results of this study have shown that they are in fact the same. This proves that one of these butterflies has evolved itself over the years to look exactly like the other so that their chances of being attacked by birds would decrease.

References

How the Butterflies Got Their Spots. (2010). Retrieved February 9, 2010, from Science Daily

Web site: http://www.sciencedaily.com/releases/2010/02/100205213102.htm