Life’s Building Blocks.
The scientific quest to determine how life began on earth is ongoing. It is likely that the more complex DNA was preceded by the simpler RNA. However, the precursor to RNA has been a matter of speculation. A new discovery may point to the answer. Cyanobacteria are among the most primitive forms of extant life. They exist virtually everywhere on the planet and can tolerate climate extremes. They also universally produce an interesting compound called aminoethylglycine (AEG). What is fascinating about AEG is that its simple structure seems to hint at a blueprint for the more complex RNA and DNA. Further study is needed to answer the question whether AEG was an early step on the road to life on earth.
Nature produces a startling array of multi-colored creatures, so a hot-pink angelfish should not surprise. However, this is not a nature’s design. Instead, it is the result of genetic engineering undertaken by Taiwanese scientists. The method involves infusing angelfish eggs with a protein that produces hot-pink offspring. These fluorescent angelfish join zebrafish as the two most brightly colored genetically engineered fish.
Human Ancestors Were Grazers.
Maybe there’s more to our love for lush green lawns then we think. Anthropologists have studied the fossils of Australopithecus bahrelghazali, among our earliest ancestors, which lived 3 to 3.5 million years ago. From the amount of carbon-13 isotopes found in these fossils, scientists believe that these hominin ancestors derived around half of their nutrition from eating grass-like plants including roots and tubers. Rather than a beginning, this seems to be a stage in human evolution that may have permitted hominin migration from East Africa into the grasslands near Lake Chad. Interestingly, still earlier hominins ate fruit and insects, not grass.
Birds Have Built-in Storm Survival Skills.
Amidst the loss and chaos that Hurricane Sandy caused east coast residents, one may wonder how the area’s birds survived. An article by Natalie Angier of the New York Times explores that ways that birds manage to anticipate and then cope with high winds and driving rain. While it is believed that hurricane related deaths among birds is minimal, a storm this size causes the forced relocation of many species not normally seen in this area. This may be a treat for bird watchers but it doesn’t last long because most bird species pack up and ship out again once the weather has calmed down.
The Missing Bats of the Caribbean.
The fossil record tells us that there was a time when there were far more bats and different bat species in the islands of the Caribbean. What drove many of these species to extinction has implications for today. 25,000 years ago, as the world warmed up following the last glacial age, ocean levels rose and rose rapidly. Scientists believe that the loss of cave habitats to ocean water happened so quickly, at least in geological terms, that many of the bat species on the islands could not adapt quickly enough and disappeared.
Crocodiles and Alligators Are Sensitive Creatures.
The many bumps on a crocodile’s or alligator’s body and around its jaws have interested scientists for some time. Among the many theories that have been proposed are that they secrete oils or detect electrical disturbances. Now, a study published in the Journal of Experimental Biology reveals that these bumps are more akin to touch sensors. In particular, they are perfectly tuned to detect even the slightest ripples in the water. The bumps, called “integumentary sensor organs,” are more sensitive than a human fingertip. This probably means that these predators not only see, hear and smell their prey, they can “feel” them in the water as well. In addition, their jaws are so sensitive that they can pick up and carry their young with delicate care.
California Millipede Re-discovered.
In 1928, a millipede found in California was described by scientists. It was rare and difficult to locate in the small area of Northern California that it called home. In 2006, the creature was “rediscovered,” and now a more detailed account of its life and habitat has been compiled. With 750 legs, the tiny millipede has more legs than any other known animal. It lives underground and looks like a thin white thread, but electron microscope scanning reveals that it has an amazingly complex body structure, especially for its small size. Perhaps most interesting, lllacme plenipes has its closest relative in South Africa. This leads to the speculation that the species was present in what is now California and South Africa, before the supercontinent Pangaea broke up 200 million years ago.
A Gene That Helps Make Us Human.
Humans share the vast majority of their DNA with their ape cousins. A new genetic discovery has shed light on one gene that evolved millions of years ago and contributed to a difference that continues to separate humans from other primates. Called miR-941, the gene cannot be found in chimpanzees, gorillas or other primates. It is unique to humans and evolved quickly, relative to evolutionary time frames. Exactly how miR-941 affects human brain function will be the focus of future research.
Flatworms’ Ability to Regrow Body Parts Under Genetic Study.
Cut off part of a flatworm and the animal re-grows the missing part — or even its entire body. The trick is in its genetics, and scientists are attempting to unravel just which genes are responsible for this impressive feat. People share quite a few genes with flatworms, so there is hope that sometime in the future, perhaps from insights learned from flatworm genetics, human genetic manipulation will allow us to re-grow diseased or damaged organs such as kidneys.
Elephants Show They Are Team Players.
Some tasks require teamwork and human intelligence excels in the area of social cooperation. But people are not the only animals who can learn to cooperate to achieve results. An experiment carried out at a Thai elephant sanctuary shows how quickly elephants can learn to work together. The experiment involved a contraption that allowed the elephants to obtain a treat only if two of them pulled on each end of a rope simultaneously. After a brief lesson on how the device worked, each elephant in the pair would wait for its partner to pull on its end of the rope. The experiment demonstrated not only that elephants understood the principle of cooperation, but that they were aware of their partner’s position with respect to the other end of the rope.
“The Dirt: This Week in Nature” curated and written by Robert Raciti.
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