Scientific American February 2010: On Newsstands Now
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Evolution: The Naked Truth (p 42)
Humans are the only primates whose bodies are covered by mostly naked skin, not by fur. The evolution of our oddly bare bodies has been crucial in the development of other human traits. In this month’s Scientific American, Nina G. Jablonski writes about the evolutionary origins of human hairlessness.
Mammals possess ample body fur for insulation, protection from external elements, and social signaling. Though various underground or aquatic mammals have also evolved hairlessness, human hairlessness is unique because it evolved to help our bodies stay cool. As Jablonski explains, the changing environment our ancestors faced 1.6 million years ago necessitated more trekking in search of food and fresh water. To help regulate body temperature during elevated levels of activity, early humans shed their fur.
Our furless evolution has had “profound consequences for subsequent phases of human evolution” – such as the enlargement and development of our most temperature-sensitive organ, the brain.
Life Science: The Prolific Afterlife of Whales (p 78)
What happens to the massive bodies of whales when they die? Those that don’t end up beached, sink down to the deep seafloor providing a unique ecosystem for various communities of organisms. As Crispin T.S. Little writes in this month’s Scientific American, a single whale carcass can support these specialized ecosystems for decades.
By studying whale-falls from offshore California, Japan and Sweden, researchers have documented over 400 species that live in and around the whale carcasses, feeding off the bubbler, meat, and exposed bones. These include bacteria that form symbiotic relationships with clams and the bizarre gutless worm called Osedax, also known as the ‘zombie’ worm.
There are an estimated 690,000 whale skeletons rotting in the world’s oceans at any time, though this is not a new phenomenon. “In fact, ever since the discovery of whale-fall communities, researchers have suspected that similar communities may have existed even earlier than the first whales, on the sunken carcasses of ancient marine reptiles, among them plesiosaurs, ichthyosaurs, and mosasaurs,” writes Little. The ecology and evolutionary history of whale-falls are crucial in understanding past oceanic reptile ecosystems as well as how present deep sea animals move between widely separated hydrothermal vents and methane seep environments.
Perspective: Comparatively Easy (p 26A)
With all the political back and forth surrounding the health care bill, it is easy to forget about some important medical initiatives that the bill would, and should, put in place. As the editors note in this month’s Scientific American, comparative effectiveness research (CER) is one such initiative. It would strengthen existing efforts, funded by last year's economic stimulus package, to collect data evaluating diverse medical procedures.
Though some politicians and pundits allege that CER’s agenda is to “ration care,” this is a damaging misconception. As the editors note, “[t]o make informed decisions, any individual and his or her doctor need evidence, so comparative effectiveness research should, in principle, make more personalized medicine possible.” It is not about cost or spending, but about weighing risks and benefits of tests and therapies, so that people receive the best available treatment.
Medicine: The Art of Bacterial Warfare (p 56)
The second leading cause of death worldwide is from the microscopic sized pathogens that lead to infectious diseases. As B. Brett Finlay discusses in this month’s Scientific American, of the tens of thousands to known bacterial species, there are only about 100 that lead to these infectious diseases.
Bacteria that make us sick have evolved to dodge our body’s immune system, and actually use our own cellular machinery to propagate. “Some of the most sophisticated mechanisms that bacteria are known to deploy are devoted to evading host defenses and even enlisting immune cells to help the microbes thrive,” writes Finlay. Our best approach for battling these microbes is to better understand the tools and tactics used to co-opt our cells and evade the body's defenses. By countering the microbes’ tactics, scientists might be able to design new ways of preventing and treating infectious disease.
Critical Mass: The Real Promise of Synthetic Biology (p 32)
The era of synthetic genomics and biology has opened up the possibility of making life from scratch. Lawrence M. Krauss writes in this month’s Scientific American, “as Spiderman would say, with great power comes great responsibility.” But this does not mean fearing the future, but instead anticipating and embracing it so that we are prepared to keep up with new technologies.
In the past decade innovation has taken researchers from sequencing the human genome, in 2001, to synthetically creating a bacteriophage in 2003, to just three years ago, turning one type of bacteria into another by genome transplantation. The fast pace of synthetic biology may alarm some and lead to apocalyptic thoughts. But we should not be governed by fear, says Krauss, because as science progresses it also sets in place voluntary systems of restrictions. Moreover, the leaps made by synthetic biology will potentially open up new avenues to benefit humankind.
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