Researchers at Lund University have studied the common bluetail damselfly for over 20 years and have observed the genetic variance in females. These variations include three different color forms, one of which gives male-like features that protect them from mating harassment.
In a new study, an international team of researchers found that this genetic variation is a shared trait among several species of damselfly. The genetic variation stemmed from changes in a specific genomic region at least five million years ago. This study is important to evolutionary biology, population genetics, and conservation biology as understanding how and why genetic variation arises and is maintained for long periods is crucial. Since all populations, of a limited size, experience genetic variation that is lost over time, it is important to understand both the mechanisms behind the emergence and persistence of genetic variation.
In a new study that was published in Nature Ecology and Evolution, researchers meticulously mapped the extensive color variation among the females of the bluetail damselfly. Of the three genetically determined color variations, one of them makes them look like males. The study clarifies how and why the color variation arose and reveals that the variation was maintained for a long period of time due to balanced natural selection. Researchers sequenced the DNA of the three color forms in bluetail damselfly females and compared it to its closely related tropical relative Ischnura senegalensis. This analysis revealed that the genetic color variation in females traces back at least five million years and involved several mutations in a specific genetic region on the thirteenth chromosome.
With the identification of the gene behind the female color variation, researchers can now further explore and identify different genotypes in the males and in the aquatic larval stage of damselflies. Researchers now have a solid foundation to investigate the color variation over longer evolutionary time scales in other damselfly species that are found globally.
This study raises questions about color signals and their function and evolutionary consequences for partner choice and conflicts between sexes. This study offers insight into conservation efforts and promotes further investigation into the ecological impacts of these genetic traits. It is also interesting to see how important the mechanism responsible for the emergence of new genetic diversity is and how it could result from different processes like mutation or genetic recombination.