Scientists Discover Reasons Behind Snakes’ ‘Shrinking Heads’
An international team of scientists led by Dr Kate Sanders from the University of Adelaide, and including Dr Mike Lee from the South Australian Museum, has uncovered how some sea snakes have developed ‘shrunken heads’ – or smaller physical features than their related species.
Their research is published today in the journal Molecular Ecology (doi: 10.1111/mec.12291).
A large head – “all the better to eat you with” - would seem to be indispensable to sea snakes, which typically have to swallow large spiny fish. However, there are some circumstances where it wouldn’t be very useful: sea snakes that feed by probing their front ends into narrow, sand eel burrows have evolved comically small heads.
The team has shown normal-shaped sea snakes can evolve such “shrunken heads” very rapidly. This process can rapidly lead to speciation (one species splitting into two).
The small-headed populations are also much smaller in absolute size than their ancestors, and these shape and size differences mean they tend to avoid interbreeding with their large-headed ancestors.
Dr Lee says, “A team led by my colleague Dr Kate Sanders at the University of Adelaide has been investigating genetic differences across all sea snakes, and we noticed that the blue-banded sea snake (Hydrophis cyanocinctus) and the slender-necked sea snake (Hydrophis melanocephalus) were almost indistinguishable genetically, despite being drastically different in size and shape.
“The slender-necked sea snake is half the size, and has a much smaller head, than the blue-banded sea snake.
“This suggested they separated very recently from a common ancestral species and had rapidly evolved their different appearances. One way this could have happened is if the ancestral species was large-headed, and a population rapidly evolved small heads to probe eel burrows - and subsequently stopped interbreeding with the large-headed forms.”
Dr Sanders says the research could have wider implications in other scientific studies: “Our results highlight the viviparous sea snakes as a promising system for studies of speciation and adaptive radiation in marine environments.”
Caption: A small-headed sea snake foraging in waters off the Ryuku Islands. Photo by Yoshitaka Tahara
Dr Michael Lee, Associate Professor
South Australian Museum and University of Adelaide
Mike.Lee@samuseum.sa.gov.au or Michael.S.Lee@adelaide.edu.au
Phone + 61 8 8207 7568)
Dr Michael Lee | Newswise
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...