Holly Lutz shows local villagers ectoparasites on the wing of an African Black-headed Oriole. This camp was at the base of Mount Gorongosa, in Gorongosa National Park, Mozambique. Photo by Federico Pardo.
Holly Lutz is out for blood. Crawling through a cramped cave to find bats, she can feel the tickle of antennae from cave crickets coating the walls, inches away. The smell of guano guides her to the cavernous roost site, where sleepy bats hang like fruit from the walls. This young Cornell Lab of Ornithology researcher has spent years collecting blood samples from birds, bats, and small mammals across five East African countries. Her goal is to clarify the evolution of a single-celled organism that originated at least half a billion years ago.
Malaria. Despite all our medical advances, the Centers for Disease Control (originally created to fight malaria in the United States) reports that about half-a-million people die of the disease each year and many more are sickened, mostly in poor, undeveloped countries. Malaria was eradicated in the U.S. in the 1950s. The cases reported now are found in people who travel here from the more than 100 countries where malaria is still a big problem. Children and pregnant women are especially vulnerable.
In a paper published in the journal Molecular Phylogenetics and Evolution, Lutz and co-authors present their analyses of DNA for 170 lineages of malaria parasites found in collected blood samples, shedding light on the little-known malarial family tree. She says the evidence strongly supports their hypothesis about the origin of malarial parasites and which mammal was infected first.
“Malaria parasites first infected reptiles and birds millions of years ago,” Lutz explains. “Our analyses show that over a long period of time and many genetic mutations later, a parasite jumped from birds into the small Miniopterus bat, which as far as we now know was the first mammal to be infected by malaria. Once established in this group of bats, the parasite was able to switch hosts again, infecting other bats and mammals, including rodents and primates.”