The research, which appears in the September issue of Current Biology, is expected to cause some controversy within the paleontological community.
"Scientists have always thought that because mammoths roamed such a huge territory—from Western Europe to Central North America—that North American woolly mammoths were a sideshow of no particular significance to the evolution of the species," said Hendrik Poinar, associate professor in the departments of Anthropology, and Pathology & Molecular Medicine at McMaster University.
Poinar and Régis Debruyne, a postdoctoral research fellow in Poinar's lab, spent the last three years collecting and sampling mammoths over much of their former range in Siberia and North America, extracting DNA and meticulously piecing together, comparing and overlapping hundreds of mammoth specimen using the second largest ancient DNA dataset available.
"Migrations over Beringia [the land bridge that once spanned the Bering Strait] were rare; it served as a filter to keep eastern and western groups or populations of woollies apart, says Poinar. "However, it now appears that mammoths established themselves in North America much earlier than presumed, then migrated back to Siberia, and eventually replaced all pre-existing haplotypes of mammoths."
"Small-scale population replacements, as we call them, are not a rare phenomenon within species, but ones occurring on a continental scale certainly are," says Ross MacPhee, curator of mammalogy at the American Museum of Natural History, and one of the researchers on the study. "We never expected that there might have been a complete overturn in woolly mammoths, but this is the sort of discoveries that are being made using ancient DNA. Bones and teeth are not always sensitive guides."
"Like paleontologists, molecular biologists have long been operating under a geographic bias," says Debruyne. "For more than a century, any discussion on the woolly mammoth has primarily focused on the well-studied Eurasian mammoths. Little attention was dedicated to the North American samples, and it was generally assumed their contribution to the evolutionary history of the species was negligible. This study certainly proves otherwise."
The origin of mammoths is controversial in itself. Some scientists believe that the first proto-mammoths arose in Africa about seven-million years ago in concert with ancestors of the Asian elephant. Around five to six million years ago, an early mammoth species migrated north into China, Siberia and, eventually, North America. This early dispersal into North America gave rise to a new mammoth known as the Columbian mammoth. Much later, back in Siberia, a cold-adapted form—the woolly mammoth—evolved and eventually crossed over the Beringian land bridge into present-day Alaska and the Yukon.
What happened next, says Poinar, is a mystery: The Siberian genetic forms began to disappear and were replaced by North American migrants.
"The study of evolution is an evolution in itself," says Poinar. "This latest research shows we're drilling down and getting a closer and better understanding of the origins of life on our planet."
Jane Christmas | EurekAlert!
Tag it EASI – a new method for accurate protein analysis
19.06.2018 | Max-Planck-Institut für Biochemie
How to track and trace a protein: Nanosensors monitor intracellular deliveries
19.06.2018 | Universität Basel
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
19.06.2018 | Physics and Astronomy
19.06.2018 | Life Sciences
19.06.2018 | Physics and Astronomy