Genetic work has split a Madagascar baobab into a new, endangered species
University of Wisconsin researchers showed that trees long filed as Adansonia za are a separate northern species, Adansonia bozy. Naming it may unlock conservation money. It also makes the old species smaller than anyone thought.
Until this week, biologists counted eight baobab species: one in Australia, one on the African mainland, and six in Madagascar. A paper in the journal Taxon, released on 14 August, adds a ninth.
Nisa Karimi, who did the work for her PhD at the University of Wisconsin-Madison, and David Baum, who has studied baobabs for more than 40 years, looked again at trees that had been lumped into Adansonia za. The northern ones look similar. Genetically they are closer to other northern Malagasy baobabs than to A. za. The team, with colleagues at the Missouri Botanical Garden and Iowa State, used targeted sequence capture on hundreds of genes and, Baum said, the split was crystal clear. They have restored the name Adansonia bozy.
Getting the DNA was the hard part. Karimi had to find the trees in remote Madagascar, then climb trunks that flower for about a month, after dusk, sometimes more than 30 metres up, because the species are hard to tell apart from leaves alone. The tissue is so rich in polysaccharides that grinding it turns slimy and breaks DNA. She had to invent a way to keep the strands long enough to read.
This is a taxonomy paper that changes a conservation budget. Karimi and Baum think A. bozy is endangered on the range they can see. In Madagascar, money often follows a threatened or endangered listing, so a named species can attract funds that a mislabelled population cannot. The flip side is A. za. Once the northern trees are removed from its count, the old species is smaller, and its own status may need to be looked at again.
You cannot conserve anything if you do not know how to describe and name them, Karimi said, and understand how they are related to other things on the landscape. That is the whole point of the paper, and it is a better kind of good news than a press-release miracle. Someone went up a tree at night, got the genes right, and a forest that was one species on paper is now two, each of which can be protected on its own terms.
The same dataset hints that another widespread species, A. rubropstipa, may also need to be split. Karimi and Baum plan to keep working in the parts of Madagascar that are still thinly sampled. The next useful step is a formal conservation assessment for A. bozy, and a recount of A. za, so the money and the fences go to the right groves.