Irish scientists make 'out of this world' discovery
Published 06/09/2011 | 05:00
IT'S life -- but not as we know it. An international team of researchers, led by Irish-based scientists, has made a groundbreaking discovery on the origin and evolution of species.
And it's all down to a three-year probe into 'water bears', a little-known, microscopic animal commonplace on Earth but which can also thrive in space. The project has disproved previous commonly held beliefs on the relationship between some animals, and is set to rock the scientific world.
Led by Dr Davide Pisani -- an evolutionary biologist at NUI Maynooth who receives funding from the Science Foundation Ireland and NASA -- the project analysed the largest hereditary, or genome, data from 33 different species of water bears.
The so-called 'bears' can be found in almost every environment on Earth and have existed for more than 600 million years.
The Maynooth-led research team found that the bears were related to insects and crustaceans and not roundworms -- changing the way scientists classify groups of animals, their relationship with each other and understanding of how they evolved.
The research proved that past assumptions concerning the relationships between some key animal groups "have been flawed".
Water bears, also known as tardigrades, thrive in the harshest conditions on the globe -- from 6,000 metres above sea-level in the Himalayas, to the deep sea and 4,000 metres underwater. They can also be found on both poles and in murky lagoons of the sun-baked equator. Virtually indestructible, the tiny creatures are able to survive in extreme environments that would kill almost any other species.
Some can survive temperatures close to absolute zero, or -273C. They have barrel-shaped bodies with four pairs of stubby legs and most range from 0.3 to 0.5mm in size. In 2007, some water bears were taken into Earth's orbit on the FOTON-M3 mission and for 10 days were exposed to the vacuum of space. On their return to Earth, it was found that many of them survived and laid eggs that hatched normally.
In May 2011, studies involving tardigrades were included on STS-134, the final flight of Space Shuttle Endeavour.
Dr Pisani said: "The research has the potential to lead to a greater knowledge of how organisms can survive in space, the more effective combating of parasites, and better methods to protect useful animals such as lobsters or honeybees.
"We knew that by focusing on the tardigrades we would be studying the most challenging species possible in terms of their genomic characters and the most difficult to analyse and classify as they evolve very fast."
Dr Pisani added: "Their genetic make-up changes faster than those of other animals, which led to false assumptions in the past about where they came from. It has been a commonly held belief that tardigrades were related to nemotodes or roundworms but our research has conclusively proven this to be incorrect and that they are in fact the sister group of arthropods such as insects or crustaceans."
Lahcen Campbell, another NUI Maynooth scientist involved in the study, said the research would also have significant implications for scientiests in other fields such as synthetic biology, geology and the study of parasites.