Baobab trees are culturally significant and have inspired a variety of arts and traditions. An international research collaboration revealed species radiation in Madagascar, followed by two species that spread long distances to Africa and Australia. By analyzing the genome, scientists have uncovered patterns that have been affected by millions of years of climate change.
Scientists have unveiled the mystery of the iconic baobab tree's origin, evolution, and spread around the world.
Also known as the upside-down tree or tree of life, the baobab tree is culturally significant and has inspired countless arts, folklore, and traditions. A research paper published in the journal Nature reveals a striking example of species radiating in Madagascar and then spreading over long distances to Africa and Australia. As species have evolved, so have the pollination mechanisms, which use eagle moths, bats, and lemurs to obtain simple nectar.
Baobab landscape. Source: Alex Antonelli (Royal Botanic Gardens, Kew)
The study involved an international collaboration between Wuhan Botanical Gardens (China), Kew Gardens, Antananarivo University (Madagascar) and Queen Mary University of London (UK).
Baobab fruit. Photo Credit: Alex Antonelli (Royal Botanic Gardens, Kew)
The charismatic baobab tree has an amazing growth pattern, with a thick and huge trunk but a noticeably short crown, hence their signature appearance as an upside-down tree. The research team first pooled the genomes of eight recognized species and studied their evolutionary patterns. They then analyzed the genome itself and found that the ancestors of all eight species were likely to have radiated in Madagascar, where they interbred, and then two species underwent amazing long journeys, one to Africa and the other to Australia. During the radiation process, these species evolved different flower structures to attract eagle moths, lemurs, and bats.
Baobab flowers. Source: Alex Antonelli (Royal Botanic Gardens, Kew)
Professor Andrew Leitch of Queen Mary, University of London, said: "We are delighted to be part of this project to uncover patterns of species differentiation in Madagascar baobab trees, followed by the discovery of two species that spread surprisingly long distances, one to Africa and the other to Australia. At the same time, eagle moths, lemurs, and bats have also been involved in the evolution of some fascinating pollination syndromes. "
The origin of the baobab tree
Dr Elijah Leitch of Kew Gardens, Kew, UK, said: "This work sheds new light on the pattern of species differentiation in baobab trees and shows how climate change has affected the distribution and species differentiation patterns of baobabs over millions of years. "
Queen Mary University of London and Royal Botanic Gardens, Kew said, Andrew and Ilia Leitch. "We are delighted to be part of this project to uncover the pattern of species differentiation of the Madagascar baobab tree before the astonishing long-distance spread of two species, one to Africa and the other to Australia. This work also sheds new light on how climate change has affected the distribution and species patterns of baobabs over millions of years. "
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DOI: 10.1038/s41586-024-07447-4
编译自/scitechdaily