Scientists have sequenced the entire genome of the tardigrade, AKA the water bear, for the first time. And it turns out that this weird little creature has the most foreign genes of any animal studied so far – or to put it another way, roughly one-sixth of the tardigrade’s genome was stolen from other species. We have to admit, we’re kinda not surprised.
A little background here for those who aren’t familiar with the strangeness that is the tardigrade – the microscopic water creature grows to just over 1 mm on average, and is the only animal that can survive in the harsh environment of space. It can also withstand temperatures from just above absolute zero to well above the boiling point of water, can cope with ridiculous amounts of pressure and radiation, and can live for more than 10 years without food or water. Basically, it’s nearly impossible to kill, and now scientists have shown that its DNA is just as bizarre as it is.
So what’s foreign DNA and why does it matter that tardigrades have so much of it? The term refers to genes that have come from another organism via a process known as horizontal gene transfer, as opposed to being passed down through traditional reproduction.