Madagascar is one of the most biodiverse places on the planet, home to more than 15,000 species of plants, 300 bird species, 300 species of amphibians and around 400 reptile species. And that’s not all: up to 90% of these species are found nowhere else on Earth. But while this wildlife hotspot may be rich in life, it is poor in terms of economy, and inhabitants will do what they need to survive. Unfortunately, this means engaging in unsustainable practices like destroying vast amounts of the island’s forest to make way for agriculture or to produce firewood.
Although we already know how important it is to reduce deforestation in order to preserve these unique habitats, the message is even clearer now following a new study that revealed that one of the island’s charismatic reptiles, the panther chameleon, is not in fact one species but perhaps as many as 11 different species.
The discovery was made by a team of researchers, headed by the University of Geneva’s professor of genetics Michel Milinkovitch, who set out to examine the incredible color diversity displayed by the panther chameleon, Fucifer pardalis. Numerous different “color morphs” are observed across the island, ranging from turquoise and green to grey and red, depending on the geographic location in which they are found.
Image credit: Michel Milinkovitch
Milinkovitch’s primary research is actually focused on the physics of the chameleon’s color-changing ability, and his team’s work has already made headlines this year after they discovered that this trick is down to active tuning of tiny crystals in skin cells, rather than shifting pigments around. But after setting off to Madagascar to find out more about this intriguing process in the panther chameleon, the team decided to extend their work by examining the genetic clues to their striking color diversity and how the variability changed across different areas of the island.
Image credit: Michel Milinkovitch
As described in Molecular Ecology, their detailed investigation involved photographing and obtaining blood samples from more than 300 individuals sampled across the entire range of the species. DNA analyses revealed high levels of genetic structure among different groups, or lineages, that displayed different dominant colors and geographical restrictions. The existence of these distinct lineages, Milinkovitch tells IFLScience, means that there is restricted gene flow between these groups and therefore low levels of interbreeding. These isolated groups, he says, must have therefore existed for a long time.
Image credit: Michel Milinkovitch
Taking this one step further, the researchers began performing statistical and mathematical analyses on the photographs obtained for each of the animals, which revealed that their coloration can predict with a high degree of certainty to which lineage the chameleon belongs. From this, the researchers were able to develop a classification key that allows the identification of distinct lineages purely by the naked eye; a useful tool for those working in the pet trade to avoid overexploitation of any particular group.
All in all, these intriguing findings led the researchers to conclude that what was originally considered to be a single, highly variable species, is actually a set of between 4-11 species. Why is this important? Well, not only does it once again highlight the sheer biodiversity present on this island, but it also has important implications for species conservation, as one species would be managed very differently than 11.
