The “grotesque” baobab has long been known as the “tree of life” for its ability to create and maintain its own ecosystem in arid regions. Since the time of the ancient Egyptians, people have marveled at what researchers say are among “the most charismatic species on our planet,” but no one knew where they originated – until now.
Currently, there are eight species of tall, wide-trunked plants, also known as upside-down trees or “mother of the forest”. Of these groups, six species are found in Madagascar, one is found throughout continental Africa, and another is found only in northwestern Australia.
But only one of these locations is the true origin of them all.
Researchers say they have solved the mystery of the “spectacular trees” using the species’ DNA. In a new study published in Naturethey said all the trees came from the African island nation of Madagascar.
Baobabs “have captivated botanists, tourists, naturalists and passers-by for centuries,” the study says. “Probably the earliest record of humans marveling at these incredible trees dates back to the Ancient Egyptians, around 2,300 BC. With their grotesque appearance, enormous size, reputed longevity and diverse uses, baobabs have become one of the most charismatic species in our world world. planet.”
Defining this charisma was difficult. But researchers say that after picking the species’ leaves and analyzing their genomes, they were able to determine that their common ancestor was based in Madagascar. Over time, members of the species were radiated off the island, forming hybrid species that would evolve to have different flowers that attract various other animals.
“We were delighted to be involved in this project which reveals patterns of baobab speciation in Madagascar, followed by the surprising long-distance dispersal of two species, one to Africa and the other to Australia,” Queen Mary University of London said Professor Andrew Leitch. “This has been accompanied by the evolution of some fascinating pollination syndromes involving hawks, lemurs and bats.”
According to the San Diego Zoo Wildlife Alliance, baobabs are “like no other.”
“A thick, bottle-shaped trunk rises to support thin branches. Baobabs are deciduous, and during the dry season (which can last up to nine months), a baobab’s bare branches resemble a gnarled root system and make these trees appear as if they were uprooted and pushed upside down,” the organization says.
The alliance asserts that trees not only play a fundamental role in their ecosystems, but also create their own. In addition to helping the soil stay moist, recycling nutrients and preventing erosion, they also provide food, water and shelter for other species.
The smallest species of baobab grows up to 5 meters, while the largest of the trees can reach around 25 meters in height, with a circumference that measures the same or even more. For comparison, a semi-truck typically sits around 72 feet long.
But many of these trees face a conservation battle. All but one of the species are included on the IUCN Red List of Threatened Species, with three considered endangered, one considered critically endangered and one considered endangered, the study says. Only one species is classified as “least concern”, although its populations are decreasing.
The DNA findings show that some of the trees have low genetic diversity, a key component to species survival as it helps establish resilience to environmental change. Their findings also suggest that climate change will “pose serious threats” to one of the Madagascar-based species and could force it to become extinct before 2080. Based on this, the study’s researchers say their findings should be reason for a reassessment of conservation. situation of baobabs.
The San Diego Zoo Wildlife Alliance has also noted a “rapid increase” in tree deaths in southern Africa.
“Of the 13 largest baobab trees on the continent, 9 collapsed and died,” the group said. “The cause is unclear, but scientists suspect that global climate change may be playing a role in the extinction of these trees.”