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Bats are the only mammals that can fly. Scientists have therefore been eager to learn how they evolved from their terrestrial ancestors. Until recently, however, even the oldest fossil bats still looked essentially like modern bats. New fossils have revealed a species that is helping to connect the dots between bats and their nonflying forebears. Findings from genetics and developmental biology have further illuminated bat origins, elucidating their place in the mammal family tree and the process by which the bat wing may have evolved. [More] 100 Years Ago: Engineering a City--New York City's Bridges DECEMBER 1958EVOLUTION OF BEHAVIOR-- “But is it not possible that beneath all the variations of individual behavior there lies an inner structure of inherited behavior which characterizes all the members of a given species, genus or larger taxonomic group--just as the skeleton of a primordial ancestor characterizes the form and structure of all mammals today? Yes, it is possible! Let me give an example which, while seemingly trivial, has a bearing on this question. Anyone who has watched a dog scratch its jaw or a bird preen its head feathers can attest to the fact that they do so in the same way. A bird also scratches with a hind limb (that is, its claw), and in doing so it lowers its wing and reaches its claw forward in front of its shoulder. One might think that it would be simpler for the bird to move its claw directly to its head without moving its wing, which lies folded out of the way on its back. I do not see how to explain this clumsy action unless we admit that it is inborn. --Konrad Z. Lorenz” [More]

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Bats are the only mammals that can fly. Scientists have therefore been eager to learn how they evolved from their terrestrial ancestors. Until recently, however, even the oldest fossil bats still looked essentially like modern bats. New fossils have revealed a species that is helping to connect the dots between bats and their nonflying forebears. Findings from genetics and developmental biology have further illuminated bat origins, elucidating their place in the mammal family tree and the process by which the bat wing may have evolved. [More] 100 Years Ago: Engineering a City--New York City's Bridges DECEMBER 1958EVOLUTION OF BEHAVIOR-- “But is it not possible that beneath all the variations of individual behavior there lies an inner structure of inherited behavior which characterizes all the members of a given species, genus or larger taxonomic group--just as the skeleton of a primordial ancestor characterizes the form and structure of all mammals today? Yes, it is possible! Let me give an example which, while seemingly trivial, has a bearing on this question. Anyone who has watched a dog scratch its jaw or a bird preen its head feathers can attest to the fact that they do so in the same way. A bird also scratches with a hind limb (that is, its claw), and in doing so it lowers its wing and reaches its claw forward in front of its shoulder. One might think that it would be simpler for the bird to move its claw directly to its head without moving its wing, which lies folded out of the way on its back. I do not see how to explain this clumsy action unless we admit that it is inborn. --Konrad Z. Lorenz” [More]

Tags: bat, behavior, wing, claw, bird

Editor's Note: This story will be published in the December 2008 issue of Scientific American. Survey the sky at twilight on a summer’s eve, and you just might glimpse one of evolution’s most spectacular success stories: bats. With representatives on every continent except Antarctica, they are extraordinarily diverse, accounting for one in every five species of mammal alive today. The key to bats’ rise to prominence is, of course, their ability to fly, which permits them to exploit resources that other mammals cannot reach. But their ascension was hardly a foregone conclusion: no other mammal has conquered the air. Indeed, exactly how these rulers of the night sky arose from terrestrial ancestors is a question that has captivated biologists for decades. [More] Is Focusing on "Hot Spots" the Key to Preserving Biodiversity? In the field of conservation, success stories about saving individual species abound. Bald eagles have recovered from their bout with the pesticide DDT; from fewer than 500 breeding pairs in 1963, the population in the lower 48 states has grown to nearly 10,000 breeding pairs, such that they are no longer listed even as threatened under the Endangered Species Act. Gray wolves have returned to Yellowstone National Park, as well as to the Italian and French Alps. The California condor has been brought back from the absolute brink of extinction, after the last surviving birds were rounded up and bred in the San Diego and Los Angeles zoos. And so on. When human ingenuity and resources are trained on a particular species, usually a charismatic one, it makes a difference--but it does not change the global pattern, which is a steady drumbeat of extinction and of the permanent loss of biodiversity that goes with it. In a recent global assessment, Stuart Butchart and his colleagues at BirdLife International in England concluded that between 1994 and 2004 conservation efforts had saved 16 species of bird from extinction, at least temporarily. During that same decade, however, another 164 bird species listed as threatened by the International Union for Conservation of Nature (IUCN) had slipped a notch closer to extinction. [More]

Tags: species, extinction, bird, conservation, bats

The baiji dolphin is functionally extinct, orangutans are disappearing and even some species of bats--the most numerous of mammals--are dying out. A new survey of the world's 5,487 mammal species--from rodents to humans--reveals that one in four are facing imminent extinction. [More] Climate change may be sparking new and bigger "dead zones" “Wasteland” conjures up visions of dusty desolation where life is fleeting and harsh--if it exists at all. Oceans, too, have their inhospitable pockets. Scientists are discovering that climate change--and not just fertilizer from farm use--may be spurring the emergence of barren underwater landscapes in coastal waters. Expanding dead zones not only spell trouble for biodiversity, but they also threaten the commercial fisheries of many nations. Dead zones are not new; they form seasonally in economically vital ecoystems worldwide, including the Gulf of Mexico and Chesapeake Bay. Agricultural runoff sparks many of these die-offs; increased use of nitrogen fertilizers has doubled the number of lifeless pockets every decade since the 1960s, resulting in 405 dead zones now dotting coastlines globally. [More]

Tags: dead, zones, mammal, climate, fertilizer

Not long after the virus that causes AIDS was identified, Margaret Heckler, then the U.S. secretary of health and human services, told a group of reporters that the discovery would enable scientists to develop a vaccine to prevent AIDS. “We hope to have such a vaccine ready for testing in approximately two years,” she declared proudly. It was 1984. Government officials have certainly been spectacularly wrong on other occasions but rarely has a large portion of the scientific community been so overly optimistic as well. Twenty-five years after isolating HIV, we still have no effective vaccine. One year ago a major clinical trial of a candidate made by Merck was shut down because it became obvious that the vaccine was not working and might even be doing harm. This past summer another vaccine hopeful was shelved and its trial canceled before it could begin because there was no reason to believe its results would be any better. [More] Taking Wing: Uncovering the Evolutionary Origins of Bats Editor's Note: This story will be published in the December 2008 issue of Scientific American. Survey the sky at twilight on a summer’s eve, and you just might glimpse one of evolution’s most spectacular success stories: bats. With representatives on every continent except Antarctica, they are extraordinarily diverse, accounting for one in every five species of mammal alive today. The key to bats’ rise to prominence is, of course, their ability to fly, which permits them to exploit resources that other mammals cannot reach. But their ascension was hardly a foregone conclusion: no other mammal has conquered the air. Indeed, exactly how these rulers of the night sky arose from terrestrial ancestors is a question that has captivated biologists for decades. [More]

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One in four mammals is in danger of disappearing because of habitat loss, hunting and climate change, a global conservation body warned on Monday.

Tags: mammals, change, climate, global, conservation

MUSICOPHILIA - TALES OF MUSIC AND THE BRAINby Oliver Sacks. Knopf, 2007 [More] Reptile Sex Determination Is Hot Topic Every expectant mother gets asked the same question: boy or girl? For mammals like us, it’s an easy call. Two X chromosomes you get pink booties. X and a Y you get blue. But for some reptiles, the answer depends on the weather. Well, on the temperature to be precise. For many lizards and turtles and gators, the sex of the hatchlings depends on the temperature in the nest where the eggs incubate.   [More]

Tags: temperature, depends, sex, reptile, blue

In the last few decades, there have been surprises on each side of the energy debate. One in 4 Mammals Threatened With Extinction, Group Finds One in four mammals is in danger of disappearing because of habitat loss, hunting and climate change, a global conservation body warned on Monday.

Tags: mammals, energy, climate, change, loss

Dawson City, Yukon--After revving up with a roar, a core drill designed to punch holes in concrete begins digging into ice more than 100,000 years old. Here in the Klondike, the drill serves as a kind of gas-powered, handheld time machine, bringing up frozen earth from the Pleistocene, when mammoths and other megafauna once ruled. In a land where miners still hunt for gold, paleomammalogist Ross Mac­Phee of the American Museum of Natural History in New York City and his colleagues seek a different kind of treasure--DNA from extinct titans. Millennia ago, as the earth in the Klon­dike cracked during the springtime thaw, water leaked in, only to freeze again during winter to form wedges of ice, explains geologist Duane Froese of the University of Alberta. Dripping in with this water was sediment from the surface, which might hold DNA from mammoths, as well as that of the plants, bacteria and other life once found in the region, MacPhee says. Nothing is known about the genetics of mammoths from the middle Pleistocene, and such DNA could elucidate their evolution. The researchers hope to find clear evidence that two species of , not just one, roamed the Americas at the end of the last ice age. [More] Not-So-Permafrost: Big Thaw of Arctic Soil May Unleash Runaway Warming "Drunken" trees listing wildly, cracked highways and sinkholes--all are visible signs of thawing Arctic permafrost. When this frozen soil warms, it releases carbon dioxide, methane and other greenhouse gases as microbes start to thrive on the organic material it contains--a potentially potent source of uncontrollable climate change. [More]

Tags: mammoth, dna, ice, kind, thaw

In the last few decades, there have been surprises on each side of the energy debate. One in 4 Mammals Threatened With Extinction, Group Finds One in four is in danger of disappearing because of habitat loss, hunting and climate change, a global conservation body warned on Monday.

Tags: mammals, energy, climate, change, loss

In the last few decades, there have been surprises on each side of the energy debate. One in 4 Mammals Threatened With Extinction, Group Finds One in four mammals is in danger of disappearing because of habitat loss, hunting and climate change, a global conservation body warned on Monday.

Tags: mammals, energy, climate, change, loss

In the last few decades, there have been surprises on each side of the debate. One in 4 Mammals Threatened With Extinction, Group Finds One in four mammals is in danger of disappearing because of habitat loss, hunting and climate change, a global conservation body warned on Monday.

Tags: mammals, energy, climate, change, loss

Elephants, gorillas and other large forest mammals may become extinct in central Africa within 50 years if hunting meat to feed starving populations continues at the current pace. Each year, rural peoples consume some 2.2 billion pounds (one million metric tons) of so-called bushmeat from wildlife, the equivalent of four million cattle; the flesh accounts for 80 percent of the protein and fat in their diet. [More] Monkey Brains Hint at Evolutionary Root of Language Processing The use of vocalizations, such as grunts, songs or barks, is extremely common throughout the animal kingdom. Nevertheless, humans are the only species in which these vocalizations have attained the sophistication and communicative effectiveness of speech. How did our ancestors become the only speaking animals, some tens of thousands of years ago? Did this change happen abruptly, involving the sudden appearance of a new cerebral region or pattern of cerebral connections? Or did it happen through a more gradual evolutionary process, in which brain structures already present to some extent in other animals were put to a different and more complex use in the human brain? A recent study in Nature Neuroscience yields critical new information, uncovering what could constitute the “missing link” between the brain of vocalizing nonhuman species and the human brain: evidence that a cerebral region specialized for processing voice, known to exist in the human brain, has a counterpart in the brain of rhesus macaques. [More]

Tags: brain, human, cerebral, year, animal

Back in March the press went crazy for Martin A. Nowak’s study on the value of punishment. A Harvard University mathematician and biologist, Nowak had signed up some 100 students to play a computer game in which they used dimes to punish and reward one another. The popular belief was that costly punishment would promote cooperation between two equals, but Nowak and his colleagues proved the theory wrong. Instead they found that punishment often triggers a spiral of retaliation, making it detrimental and destructive rather than beneficial. Far from gaining, people who punish tend to escalate conflict, worsen their fortunes and eventually lose out. “Nice guys finish first,” headlines cheered. It wasn’t the first time Nowak’s computer simulations and mathematics forced a rethinking of a complex phenomenon. In 2002 he worked out equations that can predict the way cancer evolves and spreads, such as when mutations emerge in a metastasis and chromosomes become unstable. And in the early 1990s his model of disease progression demonstrated that HIV develops into AIDS only when the virus replicates fast enough so that the diversity of strains reaches a critical level, one that overwhelms the immune system. Immunologists later found out he had the mechanism right [see “How HIV Defeats the Immune System,” by Martin A. Nowak and Andrew J. McMichael; Scientific American, August 1995]. Now Nowak is out to do it again, this time by modeling the origin of life. Specifically, he is trying to capture “the transition from no life to life,” he says. [More] One Quarter of World's Mammals Face Extinction The baiji dolphin is functionally extinct, orangutans are disappearing and even some species of bats--the most numerous of mammals--are dying out. A new survey of the world's 5,487 mammal species--from rodents to humans--reveals that one in four are facing imminent extinction. [More]

Tags: nowak, life, punishment, mammal, punish

Dawson City, Yukon--After revving up with a roar, a core drill designed to punch holes in concrete begins digging into ice more than 100,000 years old. Here in the Klondike, the drill serves as a kind of gas-powered, handheld time machine, bringing up frozen earth from the Pleistocene, when mammoths and other megafauna once ruled. In a land where miners still hunt for gold, paleomammalogist Ross Mac­Phee of the American Museum of Natural History in New York City and his colleagues seek a different kind of treasure--DNA from extinct titans. Millennia ago, as the earth in the Klon­dike cracked during the springtime thaw, water leaked in, only to freeze again during winter to form wedges of ice, explains geologist Duane Froese of the University of Alberta. Dripping in with this water was sediment from the surface, which might hold DNA from mammoths, as well as that of the plants, bacteria and other life once found in the region, MacPhee says. Nothing is known about the genetics of mammoths from the middle Pleistocene, and such DNA could elucidate their evolution. The researchers hope to find clear evidence that two species of mammoth, not just one, roamed the Americas at the end of the last ice age. [More] Not-So-Permafrost: Big Thaw of Arctic Soil May Unleash Runaway Warming "Drunken" trees listing wildly, cracked highways and sinkholes--all are visible signs of thawing Arctic permafrost. When this frozen soil warms, it releases carbon dioxide, methane and other greenhouse gases as microbes start to thrive on the organic material it contains--a potentially potent source of uncontrollable climate change. [More]

Tags: mammoth, dna, ice, kind, thaw

One in four mammals is in danger of disappearing because of habitat loss, hunting and climate change, a global conservation body warned on Monday. A Gift From the ’70s: Energy Lessons In the last few decades, there have been surprises on each side of the energy debate.

Tags: energy, mammals, gift, monday, body

One in four mammals is in danger of disappearing because of habitat loss, hunting and climate change, a global conservation body warned on Monday. A Gift From the ’70s: Energy Lessons In the last few decades, there have been surprises on each side of the energy debate.

Tags: energy, mammals, gift, monday, body

One in four mammals is in danger of disappearing because of habitat loss, hunting and climate change, a global conservation body warned on Monday. A Gift From the ’70s: Energy Lessons In the last few decades, there have been surprises on each side of the energy debate.

Tags: energy, mammals, gift, monday, body

One in four mammals is in danger of disappearing because of habitat loss, hunting and climate change, a global conservation body warned on Monday. A Gift From the ’70s: Energy Lessons In the last few decades, there have been surprises on each side of the energy debate.

Tags: energy, mammals, gift, monday, body

California’s latest initiative on climate change will help reduce global greenhouse gas emissions. Even more progress would be made if others follow. One in 4 Mammals Threatened With Extinction, Group Finds One in four mammals is in danger of disappearing because of habitat loss, hunting and climate change, a global conservation body warned on Monday.

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