Category Archives: Biology

One gene can produce many different proteins

Veronique Greenwood writes: The millimeter-long roundworm Caenorhabditis elegans has about 20,000 genes — and so do you. Of course, only the human in this comparison is capable of creating either a circulatory system or a sonnet, a state of affairs that made this genetic equivalence one of the most confusing insights to come out of the Human Genome Project. But there are ways of accounting for some of our complexity beyond the level of genes, and as one new study shows, they may matter far more than people have assumed.

For a long time, one thing seemed fairly solid in biologists’ minds: Each gene in the genome made one protein. The gene’s code was the recipe for one molecule that would go forth into the cell and do the work that needed doing, whether that was generating energy, disposing of waste, or any other necessary task. The idea, which dates to a 1941 paper by two geneticists who later won the Nobel Prize in medicine for their work, even has a pithy name: “one gene, one protein.”

Over the years, biologists realized that the rules weren’t quite that simple. Some genes, it turned out, were being used to make multiple products. In the process of going from gene to protein, the recipe was not always interpreted the same way. Some of the resulting proteins looked a little different from others. And sometimes those changes mattered a great deal. There is one gene, famous in certain biologists’ circles, whose two proteins do completely opposite things. One will force a cell to commit suicide, while the other will stop the process. And in one of the most extreme examples known to science, a single fruit fly gene provides the recipe for more than 38,000 different proteins.

But these are dramatic cases. It was never clear just how common it is for genes to make multiple proteins and how much those differences matter to the daily functioning of the cell. Many researchers have assumed that the proteins made by a given gene probably do not differ greatly in their duties. It’s a reasonable assumption — many small-scale tests of sibling proteins haven’t suggested that they should be wildly different.

It is still an assumption, however, and testing it is quite an endeavor. Researchers would have to take a technically tricky inventory of the proteins in a cell and run numerous tests to see what each one does. In a recent paper in Cell, however, researchers at the Dana-Farber Cancer Institute in Boston and their collaborators reveal the results of just such an effort. They found that in many cases, proteins made by a single gene are no more alike in their behavior than proteins made by completely different genes. Sibling proteins often act like strangers. It’s an insight that opens up an interesting new set of possibilities for thinking about how the cell — and the human body — functions. [Continue reading…]

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Why are your gut microbes different from mine?

Ed Yong writes: There are tens of trillions of bacteria in my gut and they are different from those in yours. Why?

This is a really basic question about the human microbiome and, rather vexingly, we still don’t have a good answer. Sure, we know some of the things that influence the roll call of species — diet and antibiotics, to name a few — but their relative importance is unclear and the list is far from complete. That bodes poorly for any attempt to work out whether these microbes are involved in diseases, and whether they can be tweaked to improve our health.

Two new studies have tried to address the problem. They’re the largest microbiome studies thus far published, looking at 1,135 Dutch adults and 1,106 Belgians respectively. Both looked at how hundreds of factors affect the microbiome, including age, height, weight, sleep, medical history, smoking, allergies, blood levels of various molecules, and a long list of foods. Both found dozens of factors that affect either the overall diversity of microbial species, or the abundance of particular ones. And encouragingly, their respective lists overlap considerably.

But here’s the important thing: Collectively, the factors they identified explain a tiny proportion of the variation between people’s microbiomes — 19 percent in the Dutch study, and just 8 percent in the Belgian. Which means we’re still largely in the dark about what makes my microbiome different from yours, let alone whether one is healthier than the other. [Continue reading…]

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Why it’s impossible to actually be a vegetarian

By Andrew Smith, Drexel University

In case you’ve forgotten the section on the food web from high school biology, here’s a quick refresher.

Plants make up the base of every food chain of the food web (also called the food cycle). Plants use available sunlight to convert water from the soil and carbon dioxide from the air into glucose, which gives them the energy they need to live. Unlike plants, animals can’t synthesize their own food. They survive by eating plants or other animals.

Clearly, animals eat plants. What’s not so clear from this picture is that plants also eat animals. They thrive on them, in fact (just Google “fish emulsion”). In my new book, “A Critique of the Moral Defense of Vegetarianism,” I call it the transitivity of eating. And I argue that this means one can’t be a vegetarian.

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Your lungs are full of microorganisms … and that’s a good thing

By Ian Hall, University of Nottingham

When we’re born, our lungs are thought to be sterile. But from the moment we take our first breath, our pristine lungs are exposed to all the bugs that are in the air. It has become clear in the last 10 years that the lungs rapidly acquire a population of many different microorganisms (mostly bacteria and viruses) that colonise the lungs and remain with us for the rest of our lives. This population of bugs is called the lung microbiome.

We now know more about the lung microbiome thanks to genetics. In the past, identifying the types of bugs present in the lungs depended on being able to grow them in a laboratory, and for many types of bug this was difficult. The big change that happened recently is our ability to recognise both the different bug species, and their relative abundance, by using DNA sequencing. This can be done either from a sample taken from the lungs or from sputum (the mucus we cough up when we have an infection).

Is the lung microbiome a good or a bad thing?

We all know that bacteria in the lungs can be harmful. When harmful bacteria multiply, they cause pneumonia which, despite the existence of antibiotics, can still be deadly. However, it seems that the lung microbiome usually exists in a balanced state, such that harmful types of bugs do not increase in number sufficiently to cause pneumonia. In fact, it’s possible that the very presence of such a diverse range of bugs in the lungs is one of the reasons it’s quite difficult for harmful bugs to multiply and cause disease.

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How animals think

Alison Gopnik writes: For 2,000 years, there was an intuitive, elegant, compelling picture of how the world worked. It was called “the ladder of nature.” In the canonical version, God was at the top, followed by angels, who were followed by humans. Then came the animals, starting with noble wild beasts and descending to domestic animals and insects. Human animals followed the scheme, too. Women ranked lower than men, and children were beneath them. The ladder of nature was a scientific picture, but it was also a moral and political one. It was only natural that creatures higher up would have dominion over those lower down.

Darwin’s theory of evolution by natural selection delivered a serious blow to this conception. Natural selection is a blind historical process, stripped of moral hierarchy. A cockroach is just as well adapted to its environment as I am to mine. In fact, the bug may be better adapted — cockroaches have been around a lot longer than humans have, and may well survive after we are gone. But the very word evolution can imply a progression — New Agers talk about becoming “more evolved” — and in the 19th century, it was still common to translate evolutionary ideas into ladder-of-nature terms.

Modern biological science has in principle rejected the ladder of nature. But the intuitive picture is still powerful. In particular, the idea that children and nonhuman animals are lesser beings has been surprisingly persistent. Even scientists often act as if children and animals are defective adult humans, defined by the abilities we have and they don’t. Neuroscientists, for example, sometimes compare brain-damaged adults to children and animals.

We always should have been suspicious of this picture, but now we have no excuse for continuing with it. In the past 30 years, research has explored the distinctive ways in which children as well as animals think, and the discoveries deal the coup de grâce to the ladder of nature. The primatologist Frans de Waal has been at the forefront of the animal research, and its most important public voice. In Are We Smart Enough to Know How Smart Animals Are?, he makes a passionate and convincing case for the sophistication of nonhuman minds. [Continue reading…]

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Will we know extraterrestrial life when we see it?

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Tina Hesman Saey writes: In a 1967 episode of Star Trek, Captain Kirk and crew investigated the mysterious murders of miners on the planet Janus VI. The killer, it turned out, was a rock monster called the Horta. But the Enterprise’s sensors hadn’t registered any signs of life in the creature. The Horta was a silicon-based life-form, rather than carbon-based like living things on Earth.

Still, it didn’t take long to determine that the Horta was alive. The first clue was that it skittered about. Spock closed the case with a mind meld, learning that the creature was the last of its kind, protecting its throng of eggs.

But recognizing life on different worlds isn’t likely to be this simple, especially if the recipe for life elsewhere doesn’t use familiar ingredients. There may even be things alive on Earth that have been overlooked because they don’t fit standard definitions of life, some scientists suspect. Astrobiologists need some ground rules — with some built-in wiggle room — for when they can confidently declare, “It’s alive!”

Among the researchers working out those rules is theoretical physicist Christoph Adami, who watches his own version of silicon-based life grow inside a computer at Michigan State University in East Lansing.

“It’s easy when it’s easy,” Adami says. “If you find something walking around and waving at you, it won’t be that hard to figure out that you’ve found life.” But chances are, the first aliens that humans encounter won’t be little green men. They will probably be tiny microbes of one color or another — or perhaps no color at all.

Trying to figure out how to recognize those alien microbes, especially if they are very strange, has led scientists to propose some basic criteria for distinguishing living from nonliving things. Many researchers insist that features such as active metabolism, reproduction and Darwinian evolution are de rigueur for any life, including extraterrestrials. Others add the requirement that life must have cells big enough to contain protein-building machines called ribosomes.

But such definitions can be overly restrictive. A list of specific criteria for life may give scientists tunnel vision, blinding them to the diversity of living things in the universe, especially in extreme environments, says philosopher of science Carol Cleland of the University of Colorado Boulder. Narrow definitions will “act as blinkers if you run into a form of life that’s very different.”

Some scientists, for instance, say viruses aren’t alive because they rely on their host cells to reproduce. But Adami disagrees. “There’s no doubt in my mind that biochemical viruses are alive,” he says. “They don’t carry with them everything they need to survive, but neither do we.” What’s important, Adami says, is that viruses transmit genetic information from one generation to another. Life, he says, is information that replicates.

Darwinian evolution should be off the table, too, Cleland says. Humans probably won’t be able to tell at a quick glance whether something is evolving, anyway. “Evolvability is hard to detect,” she says, “because you’ve got a snapshot and you don’t have time to hang around and watch it evolve.” [Continue reading…]

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Dolphins are helping us search for aliens

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Daniel Oberhaus writes: When twelve men gathered at the Green Bank Observatory in West Virginia to discuss the art and science of alien hunting in 1961, the Order of the Dolphin was born. A number of the brightest minds from a range of scientific disciplines, including three Nobel laureates, a young Carl Sagan, and an eccentric neuroscientist named John Lilly — who was best known for trying to talk to dolphins — were in attendance.

It was Lilly’s research that inspired the group’s name: If humans couldn’t even communicate with animals that shared most of our evolutionary history, he believed, they were a bit daft to think they could recognize signals from a distant planet. With that in mind, the Order of the Dolphin set out to determine what our ocean-going compatriots here on Earth might be able to teach us about talking to extraterrestrials.

Lilly’s work on interspecies communication has since gone in and out of vogue several times within the SETI (Search for Extraterrestrial Intelligence) community. Today, it’s back in fashion, thanks to new applications of information theory and to technological advancements, such as the Cetacean Hearing and Telemetry (CHAT) device, a submersible computer interface that establishes basic communication with dolphins. The return to dolphins as a model for alien intelligence came in 1999, when SETI Institute astronomer Laurance Doyle proposed using information theory to analyze animal communication systems, particularly the whistle repertoire of bottlenose dolphins. [Continue reading…]

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The combustion engines of life

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Alex Riley writes: For a large part of his life, Charles Darwin didn’t like peacocks. It wasn’t their loud vocalisations – a high-pitched, piercing combo of laughter and screaming. That he could deal with. What kept him up at night was the peacocks’ tails. As he wrote to a friend in 1860, the sight of those ornate feathers made him feel sick whenever he gazed at them. Why? Because he couldn’t explain them. The plumes of turquoise, blue and brown, trailing behind many times the bird’s body length or spread into a wide fan of flamboyancy, was an affront to his theory of evolution by natural selection, a process founded on efficiency and removal of extravagance.

Not only is such a train of feathers metabolically costly, it is also readily visible to any carnivore looking for an easy meal. With all the predation, pathogens and diseases that living things need to overcome, Darwin wondered, how could such self-destructive beauty evolve? Why would an animal go to such extremes to make life harder, and death more likely? He finally hit on a plausible answer in 1871. In the second part of his book The Descent of Man, he explained that there is more to life than mere survival. Animals need to have sex, too. And because females are often more heavily invested than males in egg production and parental care, they are more likely to take the lead in choosing mates, too. As Darwin wrote: ‘It’s not a struggle for existence, but a struggle between the males for the possession of the females.’

Female choice takes many forms. In some species, courting males fight each other, and the female’s decision is made for her. But in many others, males win mates by showing off through ornaments and display. Females choose those males with superior appearance or antics, and over many millennia the selected traits become amplified; nature is red in tooth and claw, but it is also no place for the ugly. In the oceans, male fish flirt using elongated dorsal fins. In the air, male butterflies glisten with iridescent tints of colour. Even ancient dinosaurs weren’t just fighters but flaunters, too. Take triceratops, an iconic dinosaur known for its three-horned face. Some studies suggest that this species’ large, bony frill, long regarded as a form of protection against predators, was actually a flashy come-hither sign to the opposite sex.

No males go to greater lengths of seduction than do the dinosaurs’ modern-day feathered descendants. As Darwin noted, birds are the most aesthetically elaborate of all animal groups: ‘They are ornamented by all sorts of combs, wattles, protuberances, horns, air-distended sacks, top-knots, naked shafts, plumes, and lengthened feathers gracefully springing from all parts of the body.’ And they don’t stop with physical display. Birds of paradise – a group of 42 species from deep within the rainforests of New Guinea – augment their gaudy plumage with carefully choreographed rituals of courtship. In Australia, bowerbirds construct gardens of locally collected objects, each categorised by colour, texture and shape. Songbirds sing for love.

If you want to understand male ornamentation, then, birds are the animals to study. And there is a lot left to understand, because Darwin merely scraped the surface. He never fully answered his own question about the value of sexual displays. When a peahen chooses a particular peacock with beautiful outspread feathers, what exactly is it that she is choosing? What is the peacock displaying? [Continue reading…]

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In order for our minds to go beyond syntax to semantics, we need feelings

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Stephen T Asma writes: After you spend time with wild animals in the primal ecosystem where our big brains first grew, you have to chuckle a bit at the reigning view of the mind as a computer. Most cognitive scientists, from the logician Alan Turing to the psychologist James Lloyd McClelland, have been narrowly focused on linguistic thought, ignoring the whole embodied organism. They see the mind as a Boolean algebra binary system of 1 or 0, ‘on’ or ‘off’. This has been methodologically useful, and certainly productive for the artifical intelligence we use in our digital technology, but it merely mimics the biological mind. Computer ‘intelligence’ might be impressive, but it is an impersonation of biological intelligence. The ‘wet’ biological mind is embodied in the squishy, organic machinery of our emotional systems — where action-patterns are triggered when chemical cascades cross volumetric tipping points.

Neuroscience has begun to correct the computational model by showing how our rational, linguistic mind depends on the ancient limbic brain, where emotions hold sway and social skills dominate. In fact, the cognitive mind works only when emotions preferentially tilt our deliberations. The neuroscientist Antonio Damasio worked with patients who had damage in the communication system between the cognitive and emotional brain. The subjects could compute all the informational aspects of a decision in detail, but they couldn’t actually commit to anything. Without clear limbic values (that is, feelings), Damasio’s patients couldn’t decide their own social calendars, prioritise jobs at work, or even make decisions in their own best interest. Our rational mind is truly embodied, and without this emotional embodiment we have no preferences. In order for our minds to go beyond syntax to semantics, we need feelings. And our ancestral minds were rich in feelings before they were adept in computations.

Our neo-cortex mushroomed to its current size less than one million years ago. That’s a very recent development when we remember that the human clade or group broke off from the great apes in Africa 7 million years ago. That future-looking, tool-wielding, symbol-juggling cortex grew on top of the limbic system. Older still is the reptile brain — the storehouse of innate motivational instincts such as pain-avoidance, exploration, hunger, lust, aggression and so on. Walking around (very carefully) on the Serengeti is like visiting the nursery of our own mind. [Continue reading…]

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Junk food is bad for plants, too

Anne Biklé and David R. Montgomery write: Most of us are familiar with the much-maligned Western diet and its mainstay of processed food products found in the middle aisles of the grocery store. Some of us beeline for the salty chips and others for the sugar-packed cereals. But we are not the only ones eating junk food. An awful lot of crops grown in the developed world eat a botanical version of this diet—main courses of conventional fertilizers with pesticide sides.

It’s undeniable that crops raised on fertilizers have produced historical yields. After all, the key ingredients of most fertilizers — nitrogen (N), phosphorus (P), and potassium (K) — make plants grow faster and bigger. And popular insecticides and herbicides knock back plant enemies. From 1960 to 2000, a time when the world’s population doubled, global grain production rose even more quickly. It tripled.

But there is a trade-off. High-yielding crops raised on a steady diet of fertilizers appear to have lower levels of certain minerals and nutrients. The diet our crops eat influences what gets into our food, and what we get — or don’t get — out of these foods when we eat them. [Continue reading…]

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The microbes that make us who we are

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Most people, however strongly they might hold to what they regard as a scientific view of life — that we are biological organisms, products of evolution, not destined for a supernatural afterlife — nevertheless most likely have a sense of identity that does not easily accommodate the idea that our thoughts and feelings are influenced by bacteria. Indeed, such an idea might sound delusional.

Yet this is what is increasingly clearly understood: that the body is not the abode of an elusive self; nor that human experience can be reduced to the aggregation of cascades of action potentials producing a neural symphony; but that this seemingly unitary being is in fact a community in which what we are and what lives inside our body cannot be separated.

Science magazine reports: The 22 men took the same pill for four weeks. When interviewed, they said they felt less daily stress and their memories were sharper. The brain benefits were subtle, but the results, reported at last year’s annual meeting of the Society for Neuroscience, got attention. That’s because the pills were not a precise chemical formula synthesized by the pharmaceutical industry.

The capsules were brimming with bacteria.

In the ultimate PR turnaround, once-dreaded bacteria are being welcomed as health heroes. People gobble them up in probiotic yogurts, swallow pills packed with billions of bugs and recoil from hand sanitizers. Helping us nurture the microbial gardens in and on our bodies has become big business, judging by grocery store shelves.

These bacteria are possibly working at more than just keeping our bodies healthy: They may be changing our minds. Recent studies have begun turning up tantalizing hints about how the bacteria living in the gut can alter the way the brain works. These findings raise a question with profound implications for mental health: Can we soothe our brains by cultivating our bacteria?

By tinkering with the gut’s bacterial residents, scientists have changed the behavior of lab animals and small numbers of people. Microbial meddling has turned anxious mice bold and shy mice social. Rats inoculated with bacteria from depressed people develop signs of depression themselves. And small studies of people suggest that eating specific kinds of bacteria may change brain activity and ease anxiety. Because gut bacteria can make the very chemicals that brain cells use to communicate, the idea makes a certain amount of sense.

Though preliminary, such results suggest that the right bacteria in your gut could brighten mood and perhaps even combat pernicious mental disorders including anxiety and depression. The wrong microbes, however, might lead in a darker direction.

This perspective might sound a little too much like our minds are being controlled by our bacterial overlords. But consider this: Microbes have been with us since even before we were humans. Human and bacterial cells evolved together, like a pair of entwined trees, growing and adapting into a (mostly) harmonious ecosystem.

Our microbes (known collectively as the microbiome) are “so innate in who we are,” says gastroenterologist Kirsten Tillisch of UCLA. It’s easy to imagine that “they’re controlling us, or we’re controlling them.” But it’s becoming increasingly clear that no one is in charge. Instead, “it’s a conversation that our bodies are having with our microbiome,” Tillisch says. [Continue reading…]

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In warm, greasy puddles, the spark of life?

Emily Singer writes: For the past 40 years, David Deamer has been obsessed with membranes. Specifically, he is fascinated by cell membranes, the fatty envelopes that encase our cells. They may seem unremarkable, but Deamer, a biochemist at the University of California, Santa Cruz, is convinced that membranes like these sparked the emergence of life. As he envisions it, they corralled the chemicals of the early Earth, serving as an incubator for the reactions that created the first biological molecules.

One of the great initial challenges in the emergence of life was for simple, common molecules to develop greater complexity. This process resulted, most notably, in the appearance of RNA, long theorized to have been the first biological molecule. RNA is a polymer — a chemical chain made up of repeating subunits — that has proved extremely difficult to make under conditions similar to those on the early Earth.

Deamer’s team has shown not only that a membrane would serve as a cocoon for this chemical metamorphosis, but that it might also actively push the process along. Membranes are made up of lipids, fatty molecules that don’t dissolve in water and can spontaneously form tiny packages. In the 1980s, Deamer showed that the ingredients for making these packages would have been readily available on the early Earth; he isolated membrane-forming compounds from the Murchison meteorite, which exploded over Australia in 1969. Later, he found that lipids can help form RNA polymers and then enclose them in a protective coating, creating a primitive cell. [Continue reading…]

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What it feels like to be an octopus

Regan Penaluna writes: In a recent Sunday, at my local Italian market, I considered the octopus. To eat the tentacle would be, in a way, like eating a brain — the eight arms of an octopus contain two-thirds of its half billion neurons. Delicious for some, yes — but for others, a jumping off point for the philosophical question of other minds.

“I do think it feels like something to be an octopus,” says Peter Godfrey-Smith, a professor of philosophy at CUNY Graduate Center, who has spent almost a decade considering the idea. Stories of octopuses’ remarkable ability to solve puzzles, open bottles, and interact with aquarium caretakers, suggest an affinity between their intelligence and our own. He wonders: What, if anything, is going on in its head — or as may be the case, its arms? The rest of its neurons are contained in lobes wrapping around its esophagus and sitting behind its eyes. This alien-like physiology is the result of almost 600 million years of evolution that separate us.

Since a 2008 dive off the coast of Sydney, Australia, where Godfrey-Smith encountered curious, 3-foot long cuttlefish, he’s been fascinated by the minds of cephalopods, which have the largest nervous systems of all the invertebrates. He’s teamed up with scientists to uncover their secret lives and behaviors, publishing in scientific journals and also a blog, where you can follow his adventures with posts that blend “natural history and philosophy.” He has a book coming out at the end of the year called Other Minds, which digs into how the octopus helps us understand the evolution of subjective experience. “I think cephalopods have a special kind of otherness, because they are organized so differently from us and diverged evolutionarily from our line so long ago,” he says. “If they do have minds, theirs are the most other minds of all.” [Continue reading…]

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Mysterious chimpanzee behaviour may be evidence of ‘sacred’ rituals

By Laura Kehoe, Humboldt University of Berlin

I trampled clumsily through the dense undergrowth, attempting in vain to go a full five minutes without getting snarled in the thorns that threatened my every move. It was my first field mission in the savannahs of the Republic of Guinea. The aim was to record and understand a group of wild chimpanzees who had never been studied before. These chimps are not lucky enough to enjoy the comforts of a protected area, but instead carve out their existence in the patches of forests between farms and villages.

We paused at a clearing in the bush. I let out a sigh of relief that no thorns appeared to be within reach, but why had we stopped? I made my way to the front of the group to ask the chief of the village and our legendary guide, Mamadou Alioh Bah. He told me he had found something interesting – some innocuous markings on a tree trunk. Something that most of us wouldn’t have even noticed in the complex and messy environment of a savannah had stopped him in his tracks. Some in our group of six suggested that wild pigs had made these marks, while scratching up against the tree trunk, others suggested it was teenagers messing around.

But Alioh had a hunch – and when a man that can find a single fallen chimp hair on the forest floor and can spot chimps kilometres away with his naked eye better than you can (with expensive binoculars) as a hunch, you listen to that hunch. We set up a camera trap in the hope that whatever made these marks would come back and do it again, but this time we would catch it all on film.

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Half of the Earth’s surface and seas must be preserved for nature, or humanity will have no future

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Edward O. Wilson writes: Unstanched haemorrhaging has only one end in all biological systems: death for an organism, extinction for a species. Researchers who study the trajectory of biodiversity loss are alarmed that, within the century, an exponentially rising extinction rate might easily wipe out most of the species still surviving at the present time.

The crucial factor in the life and death of species is the amount of suitable habitat left to them. When, for example, 90 per cent of the area is removed, the number that can persist sustainably will descend to about a half. Such is the actual condition of many of the most species-rich localities around the world, including Madagascar, the Mediterranean perimeter, parts of continental southwestern Asia, Polynesia, and many of the islands of the Philippines and the West Indies. If 10 per cent of the remaining natural habitat were then also removed – a team of lumbermen might do it in a month – most or all of the surviving resident species would disappear.

Today, every sovereign nation in the world has a protected-area system of some kind. All together the reserves number about 161,000 on land and 6,500 over marine waters. According to the World Database on Protected Areas, a joint project of the United Nations Environmental Program and the International Union for Conservation of Nature, they occupied by 2015 a little less than 15 per cent of Earth’s land area and 2.8 per cent of Earth’s ocean area. The coverage is increasing gradually. This trend is encouraging. To have reached the existing level is a tribute to those who have led and participated in the global conservation effort.

But is the level enough to halt the acceleration of species extinction? Unfortunately, it is in fact nowhere close to enough. The declining world of biodiversity cannot be saved by the piecemeal operations in current use alone. The extinction rate our behaviour is now imposing on the rest of life, and seems destined to continue, is more correctly viewed as the equivalent of a Chicxulub-sized asteroid strike played out over several human generations.

The only hope for the species still living is a human effort commensurate with the magnitude of the problem. The ongoing mass extinction of species, and with it the extinction of genes and ecosystems, ranks with pandemics, world war, and climate change as among the deadliest threats that humanity has imposed on itself. To those who feel content to let the Anthropocene evolve toward whatever destiny it mindlessly drifts, I say please take time to reconsider. To those who are steering the growth of reserves worldwide, let me make an earnest request: don’t stop, just aim a lot higher. [Continue reading…]

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Do the Hadza give their honeyguides a fair wage?

Cara Giaimo writes: In the tree-strewn savannah of northern Tanzania, near the salty shores of Lake Eyasi, live some of the planet’s few remaining hunter-gatherers. Known as the Hadza, they live in Hadzaland, which stretches for about 4,000 square kilometers around the lake. No one is sure how long they’ve been there, but it could be since humans became human. As one anthropologist put it in a recent book, “their oral history contains no stories suggesting they came from some other place.”

Anthropologists have been scrutinizing the Hadza for centuries, seeking in their stories and behavior windows to the past. The Hadza themselves, at least at times, subscribe to a food-based method of self-understanding: they describe their predecessors based on what, and how, they ate. The first Hadza, the Akakaanebe, or “ancestors,” ate raw game, plentiful and easily slain–as one ethnographer relays, “they simply had to stare at an animal and it fell dead.” The second, the Tlaatlaanebe, ate fire-roasted meat, hunted with dogs. The third, the Hamakwabe, invented bows and arrows and cooking pots, and thus expanded the menu.

The Hamaishonebe, or “modern people” — the people of today — have a variety of meal strategies. Hadza hunting and gathering grounds are shrinking, under pressure from maize farms, herding grounds, and private game reserves, and some work jobs and buy food from their neighbors. But between two and three hundred of the 1300 Hadza remaining still survive almost entirely on wild foods: tubers, meat, fruit, and honey.

Of these staples, honey is the Hadza’s overwhelming favorite. But beehives, located high up in thick-trunked baobabs and guarded fiercely by their stinging occupants, are hard to get at, and even harder to find. Enter the greater honeyguide, an unassuming black and white bird about the size of a robin. Greater honeyguides, a distinct species within the honeyguide family, love grubs and beeswax, and are great at locating hives. This is a boon for the Hadza, who, according to some estimates, get about 15 percent of their calories from honey.

When Hadza want to find honey, they shout and whistle a special tune. If a honeyguide is around, it’ll fly into the camp, chattering and fanning out its feathers. The Hadza, now on the hunt, chase it, grabbing their axes and torches and shouting “Wait!” They follow the honeyguide until it lands near its payload spot, pinpoint the correct tree, smoke out the bees, hack it open, and free the sweet combs from the nest. The honeyguide stays and watches.

It’s one of those stories that sounds like a fable — until you get to the end, where the lesson normally goes. Then it becomes a bit more confusing. [Continue reading…]

The way this story plays out has commonly been depicted as shown in the video below, but it turns out that this relationship between humans and birds might not be quite as mutually beneficial as first thought.

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Meet the world’s most notorious taxonomist

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Susie Neilson writes: In 2005, the taxonomist Quentin Wheeler named a trio of newly discovered slime-mold beetles after George W. Bush, Donald Rumsfeld, and Dick Cheney. He believed the names could increase public interest in the discovery and classification of new species, and help combat the quickening pace of extinction. (Species go extinct three times faster than we can name them.)

He knew he was onto something when, having received a call from the White House, it was Bush on the other end, thanking him for the honor. Wheeler, now the president of SUNY’s College of Environmental Science and Forestry, began attributing all sorts of provocative names to his bugs, including Darth Vader, Stephen Colbert, Roy and Barbara Orbison, Pocahontas, Hernan Cortez, and the Aztecs — he has even named 6 species after himself. Youcan call his strategy “shameless self-promotion” — Wheeler already has.

Nautilus spoke with Wheeler about his work.

What’s exciting about taxonomy?

It is the one field with the audacity to create a living inventory of every living thing on the entire planet and reconstruct the history of the diversity of life. Who else would tackle 12 million species in 3.8 billion years on the entire surface of the planet? If that isn’t real science, I don’t know what is. It infuriates me that taxonomy is marginalized as a bookkeeping activity, when in fact it has the most audacious research agenda of any biological science. [Continue reading…]

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As species migrate to escape climate change, plants get left behind

mt-tam

Climate Central reports: Willis Linn Jepson encountered a squat shrub while he was collecting botanical specimens on California’s Mount Tamalpais in the fall of 1936. He trimmed off a few branches and jotted down the location along the ridge trail where the manzanita grew, 2,255 feet above sea level.

The desiccated specimen is now part of an herbarium here that’s named for the famed botanist. It was among hundreds of thousands of specimens of thousands of different species that were used recently to track the movement of plant species up the state’s many hills.

The results of the analysis warn that native plants are struggling to keep up with changes around them as pollution from fuel burning and deforestation continues to warm the planet. Earlier research into the movement of Californian animals shows they’re shifting more quickly than the native plants.

“The big takeaway is that species are on the move, and they’re moving at different rates,” said Jon Christensen, a scientist and historian at the University of California, Los Angeles. “Which raises the concern that the ecosystems of California could be unraveling.” [Continue reading…]

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