Starvation Can Affect Future Generation Through Parental RNA

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Evidence from human famines and animal studies suggests that starvation can affect the health of descendants of famished individuals.

A new study, involving roundworms, shows that starvation induces specific changes in so-called small RNAs and that these changes are inherited through at least three consecutive generations, apparently without any DNA involvement.

Yet again, modern science hands Jean-Baptiste Lamarck a (partial) posthumous victory. File under: “Science is Weird”.

Image via Columbia University Medical Center.
From the journal Cell via Science Daily for extensive quotations from the original Columbia University Medical Center article.

The Amoeba That Eats Human Eyeballs

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Taiwanese student Lian Kao, 23, reportedly did not remove her limited-wear, disposable contact lenses for six months straight and even wore them while swimming.

As a result, amoeba got under her lenses and tunnelled through her corneas, causing permanent damage that led to blindness in both eyes. The single-cell bug, called Acanthamoeba, can survive in tap water, swimming pools and hot tubs.

Other bacteria are actually more common, it should be noted, and complete loss of sight is fairly extreme, and scarring that impairs vision partially is not uncommon in situations like this.

Via CBC News for the full article.

Carnivorous Kangaroos

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[F]ootage of a kangaroo eating a bird on the beach.

Captured by Sam from Rustic Pathways Travel in March 2013, this footage challenges current beliefs that kangaroos are strict herbivores.

Shit, Australia, are there any animals in your country that won’t murder me? I mean, I get the spiders and the snakes, but really…kangaroos, too? Today it’s just birds, but tomorrow…people. Just saying.

Still planning on going there in a year or two, though. Now I just have carnivorous kangaroos to look out for, too.

Via Sam Murray on YouTube

Firefly Communication in the Language of Light

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Light production in fireflies is due to a type of chemical reaction called bioluminescence. This process occurs in specialized light-emitting organs, usually on a firefly’s lower abdomen.

The enzyme luciferase acts on the luciferin, in the presence of magnesium ions, ATP, and oxygen to produce light.

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Light in adult beetles was originally thought to be used for similar warning purposes, but now its primary purpose is thought to be used in mate selection. Fireflies are a classic example of an organism that uses bioluminescence for sexual selection.

They have a variety of ways to communicate with mates in courtships: steady glows, flashing, and the use of chemical signals unrelated to photic systems.

Tropical fireflies, in particular, in Southeast Asia, routinely synchronise their flashes among large groups. This phenomenon is explained as phase synchronization. Current hypotheses about the causes of this behavior involve diet, social interaction, and altitude.

Video via Science Friday..
Quoted text via Wikipedia.

Madagascar Stick Bug

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The [A fallax] males are a bright electric blue and have two rows of reddish orange spines along the edges of the femur.

Females have a duller outlook. They are a light brown with red spines covering the entire thorax and the top of the head.

The male grows up to 13 cm in length while the female is much bigger and can grow up to 18, 5 cm in length.

The wings are non-functional for flight.

Thankfully, they’re vegetarians.

Or tree-etarians, as in captivity they will survive happily on bramble, raspberry, eucalyptus, or oak; it’s not entirely clear what their primary source of food is in the wild.

Via Wikipedia.

The Shrimp That Kills with Bubble Bullets

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When in colonies, the snapping shrimp can interfere with sonar and underwater communication. The shrimp are a major source of noise in the ocean.

The snapping shrimp grows to only 1–2 inches (3–5 cm) long. It is distinctive for its remarkably disproportionate large claw, larger than half the shrimp’s body.

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The claw can be on either arm of the body, and unlike most shrimp claws does not have typical pincers at the end. Rather, it has a pistol-like feature made of two parts. A joint allows the “hammer” part to move backward into a right-angled position.

When released, it snaps into the other part of the claw, emitting an enormously powerful wave of bubbles capable of stunning larger fish and breaking small glass jars.

Top image by Arthur Anker on Flickr.
Via Wikipedia.

Why Are Astronauts Weightless? Hint: It’s Not Because of Lack of Gravity

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Although the Earth’s gravity has a lesser effect on an astronaut orbiting the Earth in a spaceship than on a person on the surface of the Earth, this is not the reason why an astronaut experiences weightlessness.

The space shuttle, International Space Station and most other manned vehicles don’t get that far from the Earth. The Earth’s gravitational attraction at those altitudes is only about 11% less than it is at the Earth’s surface.

The astronaut, the spaceship and everything inside it are falling towards the Earth. The reason why the astronaut doesn’t go splat is because the Earth is curved and the astronaut, the spaceship and everything inside it are moving “sideways” fast enough that, as they fall towards the Earth, the surface of the Earth curves away from them. They are always falling towards the Earth, but they never get there.

Quoted text by Steve Gagnon via Jefferson Lab.