The Australian Lazarus Project.
A species of Australian frog known as a “gastric-brooding frog” had a strange method of bearing its offspring. It swallowed its fertilized eggs, hatched them in its stomach, and finally gave birth by spitting the newborns out of its mouth. The frog became extinct in 1983. Now the “lazarus project,” led by a team of University of New South Wales scientists, is attempting a de-extinction event. Although so far unsuccessful, scientists are using stored DNA from the extinct frog and placing it into the emptied nucleus of an egg from a related frog species. They expect that the obstacles to cloning the extinct frog are more “technical” than biological and that a living cloned gastricbrooding frog will be resurrected soon.
New Book on Animal Thoughts and Emotions.
Author Virginia Morell’s new book entitled, “Animal Wise: The Thoughts and Emotions of Our Fellow Creatures,” captures some of the many ways that animal behavior parallels human behavior. The book covers the surprisingly large vocabulary of dogs, the slapstick humor of rats and the amazing verbal intelligence of many birds. Even insects get their due, as Morell describes ants building their precisely measured colonies like miniature carpenters who measure twice and cut once.
Microbial Life Found in the Marianas Trench.
In the Marianas Trench in the Pacific Ocean, the deepest spot on the earth’s surface at a depth of some 36,000 feet, microbial life flourishes. At this depth, there is no sunlight and the water pressure is 1,100 times what it is at the surface. Nevertheless, these conditions are ideal for the countless bacteria and other microbes that make this “extreme” environment their home. Ronnie Glud of the University of Southern Denmark led a team of scientists who found that dead plant and animal matter that drifted down into the trench formed a perfect food source for bacteria and other microbes.
Jungle Cats in the English Countryside.
Darren Naish recounts his investigation into an “old world” cat—a feline species extant in Egypt and Asia but today largely disappeared from Europe. The jungle cat or swamp cat is an undomesticated feline that is larger than a domestic cat. In England, escaped specimens can be rarely found in the countryside where they prey on rabbits and rodents. They also can breed with domestic cats and hybrid species are known to exist, which are fertile. The last time the jungle cat was endemic to Britain was in the Pleistocene Epoch which lasted about 2 and a half million years, ending around 11,500 years ago.
How Roosters Know When to Crow.
An experiment with roosters conducted at Nagoya University in Japan has found that a rooster’s predawn crowing is based on its internal clock rather than external stimuli. In the experiment, roosters were exposed to 12 daylight hours and 12 dim light hours in one experiment and to 24 hours of dim light in another. In both cases, the roosters crowed at dawn or two hours before dawn. When the scientists added external stimuli such as light and sound, the roosters still responded predominantly to their own internal clock, which tells them when it is dawn. Interestingly, hierarchy plays a role in which roosters crows the earliest, with the highest ranking roosters getting that honor while the lower ranking members wait their turn.
Cholesterol Lowering Tomatoes.
A new genetically modified food comes in the form of tomatoes that have been engineered to produce a peptide that acts like a “good” cholesterol. Simply eating the tomatoes releases the peptide into the small intestine where it it takes on the functional characteristics of high-density lipoprotein or good cholesterol. One of the hopes of the research is that the antii-nflammatory effect of the peptides will alleviate conditions such as Alzheimer’s disease, as well as other chronic inflammatory diseases.
Shrunken Sea Snake Heads.
If you are a sea snake and consume large spiny fish, a big head with a large mouth would seem the correct evolutionary choice. Why, then, are some sea snake’s heads getting smaller and smaller? Dr Kate Sanders from the University of Adelaide along with other researchers have been studying this riddle and they may have an answer. When the local food choice involves pushing a snake’s head into a narrow burrow to find a tasty treat, then it pays to have a small head in fact, the smaller the better. Two sea snakes, “the bluebanded sea snake (Hydrophis cyanocinctus) and the slender-necked sea snake (Hydrophis melanocephalus) were almost indistinguishable genetically,” but the latter had developed a much smaller head. Evolutionarily speaking, this suggests an example of ongoing speciation in which two members of the same species change over time to become separate species.
More at Science Daily.
Swimming with the Stingrays.
In the Cayman Islands a burgeoning tourist attraction is swimming alongside the stingrays in the blue waters of the Caribbean. It is estimated that each stingray produces some $500,000 in annual tourism revenue for the island. The tourists also enjoy feeding the stingrays, which is where the story gets complicated. Scientists have compared stingray populations that have become habituated to human interaction and feeding with separate populations that have had little human contact. They found pronounced behavioral differences between the two groups. The tourist-acclimated stingrays changed from night hunters to day feeders and also lost their natural sense of individualism, learning to swim “fin to fin” together to enjoy the bounty provided by the tourists. Scientists warn that these kind of rapid behavioral changes can be detrimental to the stingrays in the long run and urge moderation of the feeding routines.
The Expanding Hominid DNA Tree.
Dr. Svante Pääbo and colleagues have presented a draft version of the Neanderthal genome this one the most complete to date. The highquality genome sequencing was completed using a small toe bone found in a cave in Southern Siberia in 2010. The cave where the fossils were found borders Russia, China, Mongolia and Kazakhstan and was occupied not only by our Neanderthal cousins but also by Denisovans, still another cousin on the growing list of ancient human relatives.
Sniffing for a Mate.
A new experiment seems to bolster evidence that mammals, including humans, use scent as a means of choosing a mate. Immune systems between individuals differ and it makes genetic sense to choose a mate with an immune system different from your own so as to increase the odds that your offspring will have a fuller immune arsenal. Researchers from the University of Tübingen’s Immunology department and the Proteome Center have found that mice can detect MHC (major histocompatibility complex) genes, which inform about an individual’s immune system. Different MHC peptides on cell surfaces of mice give off distinct scents and mice have special smell sensor cells that can distinguish among them. In the experiment, high concentrations of synthetic MHC peptides actually influenced the behavior of the test mice. So far, a similar system for humans has not been detected, but experimenters think it likely exists in some form.
“The Dirt: This Week in Nature” curated and written by Robert Raciti.
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