The Tardigrade, a Microscopic ‘Alien’
The so called tardigrade or aka water bear is a tiny little-microscopic water dweller which can reach an average size of about one millimeter. This little fella can withstand temperature near absolute zero and temperature well above the boiling point of water. As if that wasn’t enough, the tardigrade can withstand huge amounts of radiation and can live without the consumption of water or food for TEN years. Strangely, it is the only known animal that can survive in space. This makes it the ultimate creature that is nearly indestructible and if you aren’t amazed by all of the above mentioned facts, than read on. According to scientific analysis, researchers have determined that this little fella boasts the most foreign genes of any animal that has been mapped until now, it has the ultimate Alien DNA which means that 1/6 of its genome was stolen from other species. This mysterious ‘alien-like’ creature can in fact dry out until its body is made up of about 3% of water, and can bounce back to its normal body weight, another survival mechanism not found in any other living species.
The process by which genes are taken from another organism, opposed to traditional reproduction is referred to as horizontal gene transfer.
“We had no idea that an animal genome could be composed of so much foreign DNA,” said study co-author Bob Goldstein from the University of North Carolina at Chapel Hill. “We knew many animals acquire foreign genes, but we had no idea that it happens to this degree.”
While most animals contain 1% of foreign DNA, scientific analysis has proven that about 6000 of its genes or 17%, originated directly from foreign species.
“Animals that can survive extreme stresses may be particularly prone to acquiring foreign genes – and bacterial genes might be better able to withstand stresses than animal ones,” said researcher Thomas Boothby.
All of the above mentioned raises a number of questions like, where to its genes come from? Researchers primary believe that it is very likely that the tardigrade ‘borrowed’ some of the genomes from bacteria, plants and fungi which is why this mysterious little fella can withstand conditions that no other known animal on Earth can. This also opens up a lot of debate among astronomers and researchers about the necessary conditions of life elsewhere in the solar system and universe.
“We think of the tree of life, with genetic material passing vertically from mom and dad. But with horizontal gene transfer becoming more widely accepted and more well known, at least in certain organisms, it is beginning to change the way we think about evolution and inheritance of genetic material,” said Boothby. “Instead of thinking of the tree of life, we can think about the web of life and genetic material crossing from branch to branch … it’s exciting. We are beginning to adjust our understanding of how evolution works.”