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Dinosaurs Sat on their Hatching Eggs Like Birds.
New evidence might help settle a scientific argument over whether dinosaurs sat on their eggs like birds, or took a more reptilian approach and left them in the ground to hatch, as do crocodiles. After studying numerous fossilized dinosaur clutches of eggs, as well as determining the porosity of the egg shells, University of Calgary dinosaur researcher Darla Zelenitsky and Montana State University paleontologist David Varricchio have concluded that in at least one dinosaur species, the eggs were half-buried in the soil and the upper half was incubated by the warmth of the sitting dinosaur parent.
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Leatherback Turtles Get a Protected Home.
The leatherback turtle is the largest existing turtle; at maturity, they weigh in at around 200 pounds. An area of Puerto Rico known as the Northeast Ecological Corridor, which contains beaches and vegetation, has recently been named a federally protected area because it is a nesting grounds for the leatherback. Last summer, developers using heavy machinery crushed thousands of leatherback turtle eggs and hatchlings in the process of moving sand. This latest round in a political fight between building developers and environmentalists has gone to the environmentalists, but developers have not given up on projects such as golf courses and hotels that would severely threaten the leatherbacks.
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Rat-sized Snails Invade Florida.
Whether or not you enjoy escargot, this gigantic invasive snail species that is becoming a new threat to south Florida is not on your menu. The snails are from eastern Africa and have arrived in Florida by the exotic pet trade route and accidentally in shipments of produce. Experts call them a “trifecta” threat. Not only do they eat enormous volumes of agricultural produce, but they also chomp down on plaster and stucco thereby threatening property, and they carry a form of meningitis virus, that is a public health threat. An aggressive campaign to root out the snails is underway in the hope that they can be controlled before they invade further north.
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How to Listen to a Thirsty Tree.
Drought conditions in the United States have threatened forests as well as agriculture. When trees are in distress because of insufficient groundwater, the mechanism by which they move water up from the ground can make sounds that can alert experts that emergency measures are needed. Water molecules attract each other and it is this fundamental law that permits trees to coax water up in columns against gravity into the highest portions of the treetops. However, when the groundwater becomes inadequate, the columns of connected water inside the trees become disturbed and air bubbles form. The air bubbles give off a distinct noise pattern, called cavitations, which can be picked up with a microphone. This discovery may be the face of future forest service protections microphoned trees that will tell officials when the effects of drought are beginning to do actual harm to a forest.
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Meet the “Lion Whisperer,” Kevin Richardson.
South African Kevin Richardson has reared 27 adult lions from young animals. In this interview, he explains his philosophy of raising and living among lions as if he were a member of the pride. In 15 years of doing this work, he has suffered only minor injuries. Richardson would never attempt an interaction with a dangerous wild animal and he insists that you must give lions a wide berth when they are having a “bad day.” Words to live by.
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Cold Climates Demonstrate an Evolutionary “Rule.”
Around 150 years ago, a zoologist named Joel Allen proposed a rule of evolution. He postulated that when species adapt to cold climates, there are changes not only in the thickness of their fur, their rate of blood circulation and their metabolism, but also in their morphology, or body shape. According to Allen’s theory, cold climate species develop short limbs and thick bodies (think polar bears). This is an example of evolution complying with the laws of physics—a larger mass to surface ratio means that less energy must be expended to keep that body warm. Interestingly, the effect is not only genetic. In a single generation, mice exposed to artificially low ambient temperatures developed more stunted limbs than their counterparts who were given warmer environs.
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What Coelacanth DNA Tells Us About Our History.
Not long ago, the coelacanth was thought to have gone extinct until a live specimen was found in a South African fish market in 1938. The coelacanth is believed to be an ancient pioneering species that hundreds of millions of years ago grew limbs and made the transition from the sea to the land, thus harkening the beginning of complex land-based animals, including humans. Coelacanth DNA has been sequenced and reveals more similarity to human DNA than does other fish DNA, with the exception of the lungfish, which DNA is even closer. In a new experiment, coelacanth genes that exist in animals but not in other fish were isolated. When those genes were implanted into mouse DNA, the affected mice began to grow new limbs.
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Dogs Share their Germs with their Human Companions.
A research team from the University of Colorado at Boulder, studied the bacterial colonies on human skin and dog fur of 159 people who live in families with a dog. What surprised scientists was just how much dog bacteria is shared with the humans in their families. Associate Professor Rob Knight noted, “In fact, the microbial connection seems to be stronger between parents and family dogs than between parents and their children.” But it seems that this inter-species sharing may actually be healthful.
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Sequencing the Zebrafish Genome to Assist Medical Research.
If you were to ask the average person what people have in common with the zebrafish, the most common response would be “very little.” However, that is not the case. Two studies from the Wellcome Trust Sanger Institute reveal that sequencing the zebrafish DNA has taught us that 70% of human proteincoding genes are also found in the zebrafish genome, as well as 84% of genes implicated in human disease. In addition, by deliberately creating genetic errors in zebrafish, scientists have already isolated the genes involved in several human diseases, including cancers.
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Strange Fish Heads.
When it comes to nature, function trumps fashion. Take a look at some of the strangest looking headgear that you’ll ever see on a living creature. From banana-nosed protrusions that are used to detect electromagnetic fields to fish that wear their own fishing rod and lure on their heads, this edition of the fishery blog is both entertaining and educational.
“The Dirt: This Week in Nature” curated and written by Robert Raciti.