Saturday, November 20, 2010

Desert Adaptation: Kangaroo Rat

No matter how uninhabitable an environment might seem, chances are there is something living there. Even a place like Death Valley, which is known as the driest and hottest part of North America, plays host to a few creatures, including the Kangaroo Rat shown above. Death Valley averages less than 2 inches of precipitation per year, yet moisture evaporates at rates of up to 150 inches per year. The Kangaroo Rat can go without drinking for months to survive this dryness. So just how do they manage? They have developed behavioral and anatomical adaptations to prevent water loss during gas exchange.

Since they spend plenty of time underground to escape the daytime heat, their burrows become quite humid. When gathering seeds, rather than eating them immediately, they store them in the burrows, which allows the seeds to reabsorb the moisture in the air. The Kangaroo Rat then regains this water when they consume the seeds.

Probably the most important adaptation is the animal's efficient kidneys. Due to the rodent's lengthened loop of Henle they can produce urine which is 5 times more concentrated than maximally concentrated human urine. Because of this ability, these Kangaroo Rats never actually have to drink. The water produced within its cells during oxidation of food is sufficient for their body. Furthermore, its nasal passages can reabsorb water vapor from its own breath. To top it off, Kangaroo Rats have no sweat glands, so they can't lose water by perspiring. With all of that figured out, these little guys can focus their attention on avoiding snakes.

GM Mosquito To Stop Dengue

The human death toll caused by disease-carrying mosquitoes has risen. Currently over 2 million of the 700 million people infected by mosquitoes die annually. Scientists have attempted to control these mosquito populations using a range of methods including chemicals, lasers and radiation. Now the results have been released from a new experiment that some have called "birth control for insects", which involves the first ever release of genetically modified mosquitoes into the wild.

Due to the fact that the female mosquitoes are responsible for biting and transmitting diseases like the untreatable dengue fever, scientists considered introducing males sterilized by a genetic mutation as a tool to dramatically decrease the population.

From May to October of this year Oxitec, the Oxford-based research firm, released sterilized male mosquitoes 3 times per week in a 40-acre region of The Cayman Islands. Upon mating with a sterile male, the female would produce no offspring, in turn shrinking the next generation's population. This Sterile Insect Technique (SIT) has been used in the past, but the insects have always been rendered sterile using radiation, rather than by a genetic modification. Using this new method, by August there was an 80% drop in the mosquito population within that region.

Releasing transgenic animals into the wild is cause for concern to many environmentalists who fear that killing off an entire mosquito population could harm dependent species higher on the food chain. Oxitic insists the method is safe and will not have any permanent ecological impact since the sterilizing gene can't be passed on to future generations. The introduction of competitive species has gone awry in the past, like the disaster after Cane Toads were brought to Australia.

Wednesday, November 10, 2010

Solazyme's Algae Fuel

The United States is on the hunt for a way to lower their dependency on foreign oil. Now they appear to be closer than ever by using genetically modified algae as a new source for domestically produced fuels. The company, Solazyme, has managed to condense the naturally occurring algae-to-oil process down to just three days. They place their bioengineered algae into massive tanks and feed them with sugar cane, switch grass, and other plants. The algae's energy is transformed into a versatile oil that can be refined and used as jet fuel, diesel, cooking oil, and more.

Just how much attention is Solazyme getting for this? Well in September the US Navy ordered more than 150,000 gallons of jet fuel for testing purposes. Furthermore, they received a $21.8 million grant from the US Department of Energy to build a new refinery. The US military hopes to run 50 percent of its fleet on a mixture of renewable fuels and nuclear power by 2020. The US Navy has already tested the fuel on part of its fleet and have released promising results. They plan to test their entire non-nuclear fleet by the end of 2012. Below you can view some of the companies recent news coverage on MSNBC: