Category Archives: Life Science

Honeybees Warn Others of Risks

They trained honeybees to visit two artificial flowers containing the same amount and concentration of food. They left one flower untouched, making it a “safe” food source for the bees.

On the other flower, they placed the bodies of two dead bees, so they were visible to arriving insects, but would not interfere with their foraging. They then recorded whether and how the bees performed a waggle dance on their return to other members of the hive colony.

On average, bees returning from safe flowers performed 20 to 30 times more waggle runs that bees returning from dangerous flowers.

That shows that the bees recognise that certain flowers carry a higher risk of being killed or eaten by predators, such as crab spiders or other spider species that ambush visiting bees.

Roger Tsien Lecture On Green Florescent Protein

Nobel Laureate Roger Tsien discusses his research on green florescent protein. From the Nobel Prize web site:

n the 1960s, when the Japanese scientist Osamu Shimomura began to study the bioluminescent jelly-fish Aequorea victoria, he had no idea what a scientific revolution it would lead to. Thirty years later, Martin Chalfie used the jellyfish’s green fluorescent protein to help him study life’s smallest building block, the cell.
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when Anton van Leeuwenhoek invented the microscope in the 17th century a new world opened up. Scientists could suddenly see bacteria, sperm and blood cells. Things they previously did not know even existed. This year’s Nobel Prize in Chemistry rewards a similar effect on science. The green fluorescent protein, GFP, has functioned in the past decade as a guiding star for biochemists, biologists, medical scientists and other researchers.
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This is where the third Nobel Prize laureate Roger Tsien makes his entry. His greatest contribution to the GFP revolution was that he extended the researchers’ palette with many new colours that glowed longer and with higher intensity.

To begin with, Tsien charted how the GFP chromophore is formed chemically in the 238-amino-acid-long GFP protein. Researchers had previously shown that three amino acids in position 65–67 react chemically with each other to form the chromosphore. Tsien showed that this chemical reaction requires oxygen and explained how it can happen without the help of other proteins.

With the aid of DNA technology, Tsien took the next step and exchanged various amino acids in different parts of GFP. This led to the protein both absorbing and emitting light in other parts of the spectrum. By experimenting with the amino acid composition, Tsien was able to develop new variants of GFP that shine more strongly and in quite different colours such as cyan, blue and yellow. That is how researchers today can mark different proteins in different colours to see their interactions.

Crows Can Recognize People

Crows can recognize people and remember them for years. Listen to this interesting report from NPR. Researchers alienated a crow, and then were razzed and harassed by its family and neighbors wherever they go.

Bear Defeats Combination Bear Lock

Bear-Proof Can Is Pop-Top Picnic for a Crafty Thief

Yellow-Yellow, a 125-pound bear named for two yellow ear tags that help wildlife officials keep tabs on her, has managed to systematically decipher a complex locking system that confounds even some campers.
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“She’s quite talented,” said Jamie Hogan, owner of BearVault, based in San Diego. “I’m an engineer, and if one genius bear can do it, sooner or later there might be two genius bears. We’re trying to work on a new design that we can hopefully test on her.”

His company and New York’s Department of Environmental Conservation have cautioned campers in the Adirondacks against using the BearVault because of its vulnerability here. There have been no reports of the BearVault being regularly broken into anywhere else in the country.

So last year Mr. Hogan introduced the 450, a two-pound cylinder costing about $60, and a larger version, the 500, each with a second tab. On them, a camper must press in one tab, turn the lid partway, then press the second tab to remove the lid. “We thought, ‘O.K., well, one bump didn’t work so maybe two bumps will thwart her,'” he said.

But Yellow-Yellow figured that lid out, too.

The Calorie Delusion

The calorie delusion: Why food labels are wrong

Nutritionists are well aware that our bodies don’t incinerate food, they digest it. And digestion – from chewing food to moving it through the gut and chemically breaking it down along the way – takes a different amount of energy for different foods. According to Geoffrey Livesey, an independent nutritionist based in Norfolk, UK, this can lower the number of calories your body extracts from a meal by anywhere between 5 and 25 per cent depending on the food eaten.
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Dietary fibre is one example. As well as being more resistant to mechanical and chemical digestion than other forms of carbohydrate, dietary fibre provides energy for gut microbes, and they take their cut before we get our share. Livesey has calculated that all these factors reduce the energy derived from dietary fibre by 25 per cent
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“Cooking gives food energy,” says Wrangham. It alters the structure of the food at the molecular level, making it easier for our body to break it up and extract the nutrients.

In plants, for example, much of the energy from starch is stored as amylopectin, which is semi-crystalline, does not dissolve in water, and cannot be easily digested. Heat starchy foods with water, though, and the crystalline forms begin to melt. The starch granules absorb water, swell, and eventually burst. The amylopectin is shattered into short starch molecules called amylose, which are easily digested by the enzyme amylase.

It seems pretty obvious, just looking around, as you walk around in any city that people are much fatter, on average, than we were 20 years ago. And the data shows people were much larger (taller, but also fatter) 20 years ago than they were 100 years ago. And we know obesity causes many human health issues. The failure to address the obesity problem in the USA is another example of the failed “health care” system. Instead of a working health care system we just manage diseases that result for unhealthy living. We should be do better at providing information to people on healthy eating (including more accurate calorie counts as it concerns food we eat) and healthy lifestyle choices.

Invasive Species: Camels

Wild camels overrun resources in Outback

It’s being described as a plague. More than 1 million wild camels are wreaking havoc in huge parts of Australia, eating the vegetation, destroying property, fouling and consuming water sources, desecrating indigenous sites and causing road accidents.

About 170 years after being introduced to the continent as a pack animal to open its arid interior, Australia’s feral camel population is the biggest in the world. The camels double their numbers every nine years and continually expand their domain.
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There are proposals to build a halal abattoir in Australia and send packaged camel meat to Muslim countries. Another proposal is to turn camel meat into pet food. Although most people who have tried the meat pronounce it as tasty, similar to beef but leaner, attempts to get the Aussies to add camel to their precious “barbie” have gone nowhere.

“Australians are pretty conservative in their choice of meat,” Mr. Edwards said. “Kangaroo meat hasn’t penetrated the market; camel meat is in the same basket.” Everyone agrees that the solution should be as humane as possible.

“In their natural habitat they are wonderful,” Mr. Burrows said. “But they don’t belong here and they are causing great damage. We want to reduce their number, not eradicate them.”

The problems caused by invasive species are often much less obvious (and the species much smaller) but invasive species are a serious problem worldwide.

Pigeon Solves Box and Banana Problem

Laboratory footage showing a pigeon solving Wolfgang Kohler’s famous box-and-banana problem, which he studied with chimpanzees in the early 1900s. Depending on their previous experience, pigeons could solve this problem in a human-like fashion in as little as a minute. This pigeon has learned to push boxes and to climb, and it has been rewarded with grain for pecking at a small toy banana.

In this situation, the banana is out of reach and the box is not beneath it. At first the pigeon looks confused, then it begins pushing the box – sighting the toy banana as it pushes – and then stops pushing when the box is beneath the banana, then climbs and pecks. This and related studies were summarized in Dr. Epstein‘s 1996 book, Cognition, Creativity, & Behavior.

This is another example of interesting thoughtful bird behavior.

Ant mega-colony

Ant mega-colony takes over world

Argentine ants living in vast numbers across Europe, the US and Japan belong to the same interrelated colony, and will refuse to fight one another. The colony may be the largest of its type ever known for any insect species, and could rival humans in the scale of its world domination.
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In Europe, one vast colony of Argentine ants is thought to stretch for 6,000km (3,700 miles) along the Mediterranean coast, while another in the US, known as the ‘Californian large’, extends over 900km (560 miles) along the coast of California. A third huge colony exists on the west coast of Japan.
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While ants are usually highly territorial, those living within each super-colony are tolerant of one another, even if they live tens or hundreds of kilometres apart. Each super-colony, however, was thought to be quite distinct. But it now appears that billions of Argentine ants around the world all actually belong to one single global mega-colony.
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The team selected wild ants from the main European super-colony, from another smaller one called the Catalonian super-colony which lives on the Iberian coast, the Californian super-colony and from the super-colony in west Japan, as well as another in Kobe, Japan.

Ants from the smaller super-colonies were always aggressive to one another. So ants from the west coast of Japan fought their rivals from Kobe, while ants from the European super-colony didn’t get on with those from the Iberian colony.
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But whenever ants from the main European and Californian super-colonies and those from the largest colony in Japan came into contact, they acted as if they were old friends.

The Evolution of House Cats

Photo shows Fritz the Cat – see photos Fritz took.

Scientific American has a long and interesting article on: The Evolution of House Cats

It is by turns aloof and affectionate, serene and savage, endearing and exasperating. Despite its mercurial nature, however, the house cat is the most popular pet in the world. A third of American households have feline members, and more than 600 million cats live among humans worldwide.
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Together the transport of cats to the island and the burial of the human with a cat indicate that people had a special, intentional relationship with cats nearly 10,000 years ago in the Middle East. This locale is consistent with the geographic origin we arrived at through our genetic analyses. It appears, then, that cats were being tamed just as humankind was establishing the first settlements in the part of the Middle East known as the Fertile Crescent.
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Over time, wildcats more tolerant of living in human-dominated environments began to proliferate in villages throughout the Fertile Crescent. Selection in this new niche would have been principally for tameness, but competition among cats would also have continued to influence their evolution and limit how pliant they became. Because these proto–domestic cats were undoubtedly mostly left to fend for themselves, their hunting and scavenging skills remained sharp. Even today most domesticated cats are free agents that can easily survive independently of humans, as evinced by the plethora of feral cats in cities, towns and countrysides the world over.
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So are today’s cats truly domesticated? Well, yes—but perhaps only just. Although they satisfy the criterion of tolerating people, most domestic cats are feral and do not rely on people to feed them or to find them mates. And whereas other domesticates, like dogs, look quite distinct from their wild ancestors, the average domestic cat largely retains the wild body plan. It does exhibit a few morphological differences, however—namely, slightly shorter legs, a smaller brain and, as Charles Darwin noted, a longer intestine, which may have been an adaptation to scavenging kitchen scraps.

Cats are Cool 🙂

Sustainable Aquaculture

Located on an island in the Guadalquivir river, 10 miles (16km) inland from the Atlantic, Veta la Palma produces 1,200 tons of sea bass, bream, red mullet and shrimp each year. Yet unlike most of the world’s fish farms, it does so not by interfering with nature, but by improving upon it. “Veta la Palma raises fish sustainably and promotes the conservation of birdlife at the same time,” says Daniel Lee, best practices director for the U.S.-based Global Aquaculture Alliance. “I’ve never seen anything quite like it.”

With wild fish stocks declining precipitously around the globe, thanks to overfishing and climate change, aquaculture has emerged as perhaps the only viable way to satisfy the world’s appetite for fish fingers and maki rolls. In the next few years, consumption of farm-raised fish will surpass that caught in the wild for the first time, according to the United Nations Food and Agriculture Organization. But most fish farms — even ones heralded as “sustainable” — create as many problems as they solve, from fecal contamination to the threat that escaped cultivated fish pose to the gene pool of their wild cousins.

Veta la Palama is different. In 1982, the family that owns the Spanish food conglomerate Hisaparroz bought wetlands that had been drained for cattle-farming and reflooded them. “They used the same channels built originally to empty water into the Atlantic,” explains Medialdea. “Just reversed the flow.” Today, that neat little feat of engineering allows the tides to sweep in estuary water, which a pumping station distributes throughout the farm’s 45 ponds. Because it comes directly from the ocean, that water teems with microalgae and tiny translucent shrimp, which provide natural food for the fish that Veta la Palma raises.

By hewing as closely as possible to nature, the farm avoids many of the problems that that plague other aquaculture projects. Low density — roughly 9 lb. (4 kg) of fish to every 35 cu. ft. (1 cu m) of water — helps keep the fish free of parasites (the farm loses only 0.5% of its annual yield to them). And the abundant plant life circling each pond acts as a filter, cleansing the water of nitrogen and phosphates.