Researchers Have Created The Most Reliable Evolutionary Tree Of Scorpion Species By Analyzing Their Venom
As far as most people are concerned, scorpion species generally look the same. They all have pincers and a stinger that is attached to the end of a menacing looking tail. The only variance between scorpion species may be body size and color, but beyond these two features, what other physical traits vary across scorpion species? As it happens, this question is still being asked by many entomologists and evolutionary biologists working today. This is because a reliable evolutionary tree detailing scorpion evolution has never been accurately mapped out. Creating a family tree of existing scorpion species is difficult because very little phenotypic variation exists between the more than 2,000 scorpion species that have been documented and described by scientists. This is surprising considering that scorpions have adapted to living in a variety of different types of environments in all continents in the world except for Antarctica. Most other arthropods that are species-rich and widely distributed have developed unique physical traits in order to adapt to new environments, but scorpions have maintained a similar physical appearance for the 300 to 400 million years in which they have existed. However, one determined researcher recently created the first accurate and comprehensive evolutionary tree of scorpion species by analyzing the molecular shape of different venoms.
A postdoctoral researcher at the University of Wisconsin in Madison created an evolutionary tree of scorpion species by using available genetic information. However, genetic data was not sufficient for creating a comprehensive family tree of scorpions. This inadequate first map led Lopez to analyze the 3D structure of the molecules in the venom of different scorpion species. Basically, Lopez created a second tree that mapped out different venoms and their relative similarities and differences to one another. By applying this second map to the first map of genetic relatedness between available scorpion DNA samples, Lopez succeeded in mapping out the evolutionary family tree of scorpions. The shape of different venom molecules also indicates the particular prey-animals that each scorpion species is adapted to hunt. This information could be used to geographically map-out various scorpion habitats around the world.
Did you know that scorpions are one of the oldest arachnid species known to humankind?