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03.21.2013

the eerie genetic similarity of giant squid

Giant Squid

The giant squid is one of Nature’s most elusive animals. In fact, the first video of the animal in it’s natural habitat was only captured this January. Now a new study of the DNA in squids from around the world shows that they are all the same species. The study appears in PNAS. It looks at the DNA from dead squid that had washed ashore around the world and compared the sequences. It turns out that they are all eerily similar. The species has very little genetic diversity. From Scientific American:

When the researchers looked closely at the mitochondrial DNA of the creatures, they noticed something remarkable. Irrespective of where they came from — be it be it California, Japan, South Africa, New Zealand or somewhere else — the squid were genetically very similar.

In fact, the diversity of Architeuthis is lower than that for any other marine animal, except one — the basking shark Cetorhinus maximus, whose current population is thought to have rebounded from a small number of individuals. At first, says Thomas Gilbert, a geneticist at the University of Copenhagen and an author of the study, “When we found that the global genetic diversity of the giant squid was this low, we figured we had made an error.” But then the team checked their numbers again and saw that they were correct.

The findings not only make it clear that all giant squid around the world are the same species, but they also hint that, like the basking shark, the animals came close to extinction at some point in the not too distant past. The results are published inProceedings of the Royal Society B.

03.20.2013

coming back from extinction

(Image: Mike Tyler/ANT Photo Library/Science Source)

Researchers are working to bring a frog that gives birth through its mouth back from extinction. The New Scientist reports:

Habitat destruction drove the gastric-brooding frog (Rheobatrachus silus) to extinction in 1983, but researchers have now created an early frog embryo from frozen specimens with the goal of bringing it back to life.

The gastric brooding frog was the only animal known to give birth through its mouth. It swallows its eggs after laying them, lets them grow for about six weeks, and then dribbles out tadpoles.

To clone the frog, Michael Archer and colleagues at the University of New South Wales in Sydney, Australia, isolated the nuclei from the cells of frogs that had been frozen for 40 years. They transferred them into the eggs of a modern frog, Mixophyes fasciolatus, which then divided several times as if to form an early embryo. The research, which has not yet been published, was presented at a TED^x conference on “de-extinction” in Washington DC last week.

03.19.2013

graphene desalination

Graphene

We’ve mentioned the wonders of graphene a number of times on this blog. Lockheed Martin is now trying to add another: large scale desalination of sea water. They are in the process of developing a prototype to produce drinking water from sea water using a graphene filter. From NBC News:

A defense contractor better known for building jet fighters and lethal missiles says it has found a way to slash the amount of energy needed to remove salt from seawater, potentially making it vastly cheaper to produce clean water at a time when scarcity has become a global security issue.

The process, officials and engineers at Lockheed Martin say, would enable filter manufacturers to produce thin carbon membranes with regular holes about a nanometer in size that are large enough to allow water to pass through but small enough to block the molecules of salt in seawater. A nanometer is a billionth of a meter.

Because the sheets of pure carbon known as graphene are so thin — just one atom in thickness — it takes much less energy to push the seawater through the filter with the force required to separate the salt from the water, they said.

The prototype is expected to be completed by the end of this year. Lockheed Martin hopes to be able to commercialize the product sometime in 2014 or 2015.