In 1533, Bom Jesus – a Portuguese merchant ship carrying 40 tons of cargo, including gold, silver, copper, and more than 100 ivory teeth – sank off the coast of Africa near present-day Namibia. The wreckage was discovered in 2008, and scientists say they have now identified the source of most of the ivory removed from the ship.
The study was reported in the journal Available Biology, used a variety of techniques, including a genomic analysis DNA were removed from well-preserved teeth to determine elephant species, geographical origin, and the types of landscapes they inhabited before they were killed.
The ivory was collected under the load of a heavy copper and lead ingot at the lower level of Bom Jesus, said Alida de Flamingh, a post-doctoral student at the University of Illinois at Urbana-Champaign, who led the study with the U. animal. Professor of Sciences Alfred Roca and Professor of Anthropology Ripan Malhi.
“When the ship sank, the ingots clenched their teeth into the seabed and caused a great deal of physical wear and tear of the sea currents, causing the shipwreck to collapse and collapse,” Flamingh said. “There is also an extremely cold sea current off the coast of Namibia, which has probably helped protect the DNA in the ship’s sunken teeth.”
The team extracted DNA from 44 teeth.
By analyzing the genetic sequence known to distinguish between the African forest and the savannah elephant, the scientists determined that all the teeth they analyzed belonged to the forest elephant. Another examination of mitochondrial DNA, passed from mother to offspring only, suggested a more precise geographical origin of ivory than elsewhere.
“Elephants live in matriarchal family groups and tend to stay in the same geographic area for the rest of their lives,” Flamingh said. “By comparing the ship’s wrecked ivory with mitochondrial DNA and the DNA of elephants of known African origin, we were able to pinpoint specific areas and species of elephants whose teeth were found at the site of the shipwreck.”
All 44 teeth were from elephants living in West Africa. None of them originated in Central Africa.
“This is consistent with the creation of Portuguese shopping malls along the West African coast at this time in history,” Flamingh said.
The team used Languages to 17 generations of families known to have only four of the elephants remaining in Africa.
“Other generations have become extinct because West Africa has lost more than 95% of its elephants in the following centuries due to the destruction of hunting and habitat,” he said.
The team adds a new DNA sequence to Loxodonta Localizer, an open access tool developed in the United States, that allows users to compare the mitochondrial DNA sequences they collect from hunted ivory with those in online databases collected from elephants. The African continent.
To learn more about the environment in which elephants live, Ashley Coutu, a researcher and co-author of the Pitt Rivers Museum at Oxford University, analyzed stable carbon and nitrogen isotopes in 97 teeth. The proportion of these isotopes varies depending on the plant species consumed by the elephants and the amount of rainfall around them.
This analysis revealed that elephants live in mixed habitats, migrating from forested areas to savannas in different seasons, most likely in response to water availability.
“Our taxes help us understand the ecology associated with the conservation of modern wildlife in the historic landscape of the West African forest elephant,” he said.
“Our study analyzed the largest archaeological load ever found on an African ivory,” Flamingh said. “By combining complementary analytical approaches from many scientific fields, we have been able to clarify the origin of ivory with a resolution that cannot be used without any approach. The study provides a framework for exploring the vast collections of historical and archaeological ivory in museums around the world. ”
de Flamingh, IU Carl R. Woese conducted DNA analysis at the Malhi Molecular Anthropology Laboratory at the Institute of Genomic Biology. The project was a very institutional effort involving collaborators from Namibia, South Africa, the United Kingdom and the United Kingdom. USA
Reference: December 17, 2020, Available Biology.
DOI: 10.1016 / j.cub.2020.10.086
The study was supported by the US Fish and Wildlife Fund, the African Elephant Conservation Foundation, the US Department of Agriculture, the South African National Research Foundation, the South African Ministry of Science and Technology, and the Claude Leon Foundation.