The iconic baobabs, or upside-down trees, are culturally significant and have inspired various arts and traditions. An international research collaboration revealed species radiation in Madagascar, followed by the long-distance dispersal of two species to Africa and Australia. Analyzing genomes, scientists found patterns influenced by climate change over millions of years.
The mystery behind the origin, evolution, and dispersal around the world of iconic baobabs has been solved by scientists.
Also known as upside-down trees, or the tree of life, the iconic baobabs have much cultural significance, inspiring innumerable arts, folklore, and traditions. A research paper published in Nature reveals a remarkable example of species radiation in Madagascar followed by long-distance dispersal to Africa and Australia. With speciation, an astonishing divergence of pollination mechanisms evolved, that exploit hawkmoths, bats, and lemurs for a simple nectar reward.
Baobab landscape. Credit: Alex Antonelli (Royal Botanic Gardens, Kew)
The study involved international collaboration between Wuhan Botanical Garden (China), Royal Botanic Gardens (Kew, UK), University of Antananarivo (Madagascar), and Queen Mary University of London (UK).
Baobab fruit. Credit: Alex Antonelli (Royal Botanic Gardens, Kew)
Baobab fruit. Credit: Alex Antonelli (Royal Botanic Gardens, Kew)
Baobabs’ Unique Growth and Pollination
The charismatic baobabs have astonishing growth forms, reaching huge sizes with massive trunks, but apparently diminutive crowns, giving them their iconic appearance as upside-down trees. The team first assembled the genomes of the eight recognized species and worked out their patterns of speciation. They then analyzed the genomes themselves and discovered that the ancestor of all eight species most likely radiated in Madagascar, where they made hybrids, before two species underwent astonishing long-distance travels, one to Africa and another to Australia. In that radiation, the species evolved different flower structures to attract hawkmoths, lemurs, and bats.
Baobab flower. Credit: Alex Antonelli (Royal Botanic Gardens, Kew)
Insights From Leading Researchers
Professor Andrew Leitch at Queen Mary University of London said, “We were delighted to be involved in this project uncovering patterns of baobab speciation in Madagascar followed by the astonishing long-distance dispersal of two species, one to Africa and another to Australia. This was accompanied by the evolution of some fascinating pollination syndromes involving hawkmoths, lemurs, and bats.”
Origin of the baobabs. Credit: Queen Mary University of London
Dr. Ilia Leitch at Royal Botanic Garden Kew said, “This work has uncovered new insights into the patterns of speciation in baobabs and shows how climate change has influenced baobab distribution and speciation patterns over millions of years.”
Baobabs. Credit: Alex Antonelli (Royal Botanic Gardens, Kew)
Husband and Wife Research Team
Husband and wife team Andrew and Ilia Leitch at Queen Mary University of London and Royal Botanic Gardens Kew said. “We were delighted to be involved in this project uncovering patterns of baobab speciation in Madagascar before the astonishing long-distance dispersal of two species, one to Africa and another to Australia. The work also provides new insights into how climate change has influenced baobab distribution and speciation patterns over millions of years.”
For more on this research, see Decoding the Mysterious Origins of Baobab Trees.
Reference: “The rise of baobab trees in Madagascar” by Jun-Nan Wan, Sheng-Wei Wang, Andrew R. Leitch, Ilia J. Leitch, Jian-Bo Jian, Zhang-Yan Wu, Hai-Ping Xin, Mijoro Rakotoarinivo, Guy Eric Onjalalaina, Robert Wahiti Gituru, Can Dai, Geoffrey Mwachala, Ming-Zhou Bai, Chen-Xi Zhao, Hong-Qi Wang, Sheng-Lan Du, Neng Wei, Guang-Wan Hu, Si-Chong Chen, Xiao-Ya Chen, Tao Wan and Qing-Feng Wang, 15 May 2024, Nature.
DOI: 10.1038/s41586-024-07447-4
