all zoology stories

Boning up on frogs' defenses

404132862 — Tue, 24 Jun 2008 14:13:51 -0400

Harvard biologists have determined that some African frogs carry concealed weapons: when threatened, these species puncture their own skin with sharp bones in their toes, using the bones as claws capable of wounding predators.

The unusual defense mechanism is described by Harvard's David C. Blackburn, James Hanken, and Farish A. Jenkins, Jr., in a forthcoming issue of the journal Biology Letters.

Leading scientists announce creation of Encyclopedia of Life

50443248 — Tue, 02 Oct 2007 12:00:45 -0400

Realizing a dream articulated in 2003 by renowned biologist E.O. Wilson, Harvard and four partner institutions have launched an ambitious effort to create an Encyclopedia of Life (EOL), an unprecedented project to document online every one of Earth's 1.8 million known species. For the first time in history, the EOL would grant scientists, students, and others multimedia access to all known living species, even those just discovered.

The effort, announced today (May 9), will be supported by a new $10 million grant from the John D. and Catherine T. MacArthur Foundation and $2.5 million from the Alfred P. Sloan Foundation.

Eggs, nests make colorful bedfellows at HMNH

50443248 — Tue, 02 Oct 2007 11:00:00 -0400

Large and small, plain and colored, splotched and dotted, eggs from the Harvard Museum of Comparative Zoology’s vast collection are on display at the Harvard Museum of Natural History in a new exhibition of eggs and nests.

The nests, like the eggs, come in all shapes and sizes. Unlike eggs, which have the same basic plan, nests vary greatly in complexity, from the simple dirt mounds of reptiles to the elaborate creations of Africa’s weaver birds to no nests at all.

Opossum genome shows 'junk' DNA source of genetic innovation

50443248 — Wed, 09 May 2007 16:51:38 -0400

A tiny opossum's genome has shed light on how evolution creates new creatures from old, showing that change primarily comes by finding new ways of turning existing genes on and off.

The research, by an international consortium led by the Broad Institute of MIT and Harvard, revises our understanding of genetic evolution. Scientists previously thought that evolution slowly changed the genes that create specific proteins. As the proteins changed, so did the creatures that owned them.

The current research shows that opossum and human protein-coding genes have changed little since their ancestors parted ways, 180 million years ago. It has been the regulation of their genes - when they turn on and off - that has changed dramatically.

"Evolution is tinkering much more with the controls than it is with the genes themselves," said Broad Institute director Eric Lander. "Almost all of the new innovation ... is in the regulatory controls. In fact, marsupial mammals and placental mammals have largely the same set of protein-coding genes. But by contrast, 20 percent of the regulatory instructions in the human genome were invented after we parted ways with the marsupial."

The research, released May 9 also illustrated a mechanism for those regulatory changes. It showed that an important source of genetic innovation comes from bits of DNA, called transposons, that make up roughly half of our genome and that were previously thought to be genetic "junk."

The research shows that this so-called junk DNA is anything but, and that it instead can help drive evolution by moving between chromosomes, turning genes on and off in new ways.

Jane Goodall: A life in the field

Tue, 10 Jul 2007 16:20:12 -0400

As a girl in England, Jane Goodall had a toy chimpanzee named Jubilee — a harbinger of the primatologist she was to become and of the jubilant audiences that greet her at every turn in adulthood.

Beginning in 1960, her groundbreaking studies of chimpanzees in the African wild led to a series of revelations that revolutionized the scientific understanding of these close human relatives.

Goodall, a onetime secretary who skipped past a bachelor's degree to do a doctorate in ethnology at the University of Cambridge, famously discovered that chimpanzees make and use tools, thrive in socially complex families, and even engage in warfare.

Wilson urges alliance to save species

50443248 — Wed, 03 Oct 2007 10:01:31 -0400

Edward O. Wilson sees a future in which science and religion join forces to save the natural world.

Without such an alliance, said the legendary Harvard biologist and author, an alternative future is in store for the human race: one of accelerating environmental cataclysm fueled by overpopulation, deforestation, declining fisheries, and climate change.

If nothing is done, by the end of the century one-half of all species will be gone, or nearly gone, said Wilson, Pellegrino University Professor Emeritus. In the next 50 years, a quarter of those species will become extinct because of climate change alone. That's a fast blow to Earth's biodiversity, which took 3.5 billion years to evolve.

Students search for Thompson Island's hoppers

70652986 — Mon, 26 Mar 2007 05:46:41 -0400

Education met hands-on science on Boston Harbor's Thompson Island on Oct. 9, 2006, as roughly 100 Harvard undergraduates fanned out from beach to beach collecting insects to be included in a new database of Harbor Island insect life.

The students, part of biology professors Brian Farrell and Missy Holbrook's OEB 10 class, "Foundations of Biological Diversity," spent a warm and sunny October day combing the island, literally beating the bushes and scooping up all types of insects in nets.

Farrell, who led the excursion, said the trip served several purposes. First, it exposed students studying biological diversity to the most diverse group of animals on the planet.

How Darwin's finches got their beaks

Thu, 12 Jul 2007 15:01:32 -0400

Darwin's finches are the emblems of evolution. The birds he saw on the Galapagos Islands during his famous voyage around the world in 1831-1836 changed his thinking about the origin of new species and, eventually, that of the world's biologists.

Darwin wondered about the changes in shape of bird beaks from island to island. So-called cactus finches boast longer, more pointed beaks than their relatives the ground finches. Beaks of warbler finches are thinner and more pointed than both. These adaptations make them more fit to survive on available food.

Monkey see, monkey infer

70652986 — Mon, 26 Mar 2007 06:26:58 -0400

Monkeys keep turning out to be smarter than people think they are. Researchers have shown that they can count to four and are aware of differences between languages like Dutch and Japanese, even though they don't known what is being said. Now, Harvard psychologists find that monkeys can draw correct conclusions about novel situations. For example, shown a white towel that turns blue, a blue knife, and a glass of blue paint, they can figure out that the paint, not the knife, is responsible for the change in color.

"Our studies reveal a striking continuity between humans and monkeys in their capacity to draw causal inferences without the help of familiarity with the events or situation," says Marc Hauser, a Harvard professor of psychology. "This ability highlights the richness of the monkey mind in terms of its understanding of the material world."

Hauser has been working with a colony of free-ranging rhesus monkeys on an island off Puerto Rico for many years. He and Bailey Spaulding, formerly a student of his, tested individual adult males and females of the colony on their ability to figure out cause and effect in unfamiliar situations.

In their experiments, they used a glass of water and a knife along with a whole apple and an apple cut in half. The knife can halve the apple, but the water can't. Do the monkeys grasp this?

In one set of tests the monkeys saw a glass of water and two whole apples. Then they viewed a knife being lowered and the apple cut in half. These are two perfectly plausible situations. Next, they saw the glass of water and two halves of an apple. Following this, a knife was lowered, and two apple halves seemingly became a whole apple.

To a human, even an infant who had never seen such things before, the last two apparent happenings would never really happen. Can monkeys infer the same outcomes? Evidently, the answer is "yes." They looked longer when a glass of water appeared to cut the apple than when a knife seemed to do the same. The longer look signaled disbelief.

Researchers create pigs that produce omega-3 fatty acids

70652986 — Mon, 26 Mar 2007 06:25:39 -0400

Researchers report they have created pigs that produce omega -3 fatty acids, which are known to improve heart function and help reduce the risks for heart disease, representing the first cloned transgenic livestock in the world that can make the beneficial compound. The research could be a boost to both farmers and health-conscious consumers seeking an alternative and safer source of omega-3 fatty acids. Currently, the only way for humans to realize the benefits of omega-3 fatty acids is by taking dietary supplements or by eating certain types of fish that may also contain high levels of mercury.

The results, published by Nature Biotechnology, are the work of a team assembled by Yifan Dai, M.D., Ph.D., of the University of Pittsburgh School of Medicine that includes researchers from Randy Prather's group at the University of Missouri-Columbia National Swine Resource and Research Center, the laboratory of Jing X. Kang, M.D., Ph.D., at Massachusetts General Hospital (MGH), and the laboratories of Dai and Rhobert Evans at the University of Pittsburgh.

The transgenic pigs were created using technology developed by Kang of MGH, an associate professor of medicine at Harvard Medical School and co-lead author of the current report with MU's Liangxue Lai. Kang's group created the first omega-3 rich mammals (mice) and published that work in Nature in 2004.

The production of these pigs will now provide researchers with opportunities to conduct studies not previously possible.

Dog genome unleashed

70652986 — Mon, 26 Mar 2007 06:23:31 -0400

An international research team led by scientists at the Broad Institute of MIT and Harvard has decoded the DNA of the domestic dog and pinpointed millions of genetic differences that distinguish dog breeds. The study also includes the first comparative analysis to encompass three distinct mammalian genomes, revealing important DNA elements common among them. Such shared genetic signatures offer crucial insights into genome organization and function, particularly in humans. Their efforts, described in the Dec. 8, 2005 issue of Nature, shed light on the genetic similarities between dogs and humans as well as the genetic differences between dog breeds, and may guide future discoveries that improve the health of both species.

"Of the more than 5,500 mammals living today, dogs are arguably the most remarkable," said senior author Eric Lander, director of the Broad Institute, professor of biology at MIT and of systems biology at Harvard Medical School, and a member of the Whitehead Institute for Biomedical Research. "The incredible physical and behavioral diversity of dogs - from chihuahuas to great danes - is encoded in their genomes. It can uniquely help us understand embryonic development, neurobiology, human disease and the basis of evolution."

More than two years ago, the Nature paper's authors embarked on a mission to assemble a complete map of the dog genome. In the first phase of the project they obtained high-quality DNA sequence from a female boxer named "Tasha," covering nearly 99 percent of the dog's genome. Because dogs sit at a key branch point in the evolutionary tree relative to humans, the dog genome sequence enabled researchers to make novel observations regarding the genetic similarities among mammals.

Wing color not just for looks

70652986 — Mon, 26 Mar 2007 05:41:13 -0400

Harvard and Russian researchers have documented natural selection's role in the creation of new species through a process called reinforcement, where butterfly wing colors differ enough to avoid confusion with other species at mating time, helping the butterflies avoid creating less-fit hybrid offspring.

Though more distantly related species tend to be more physically distinct, researchers found this was not the case with species of the blue butterfly Agrodiaetus, found in a broad swath across much of Central Asia and Europe. Researchers found instead that species that might be expected to have the most trouble telling each other apart had the greatest differences in wing color.

That meant that newly diverged species living in the same area that could still mate and have hybrid young had more distinctive wing colors than other closely-related species that had diverged at an earlier time, as well as those living in different areas from each other.

Hessel Professor of Biology Naomi Pierce said a critical factor in this research is the fact that the butterflies are still closely related enough that they can - and sometimes do - interbreed. The hybrids created by this interbreeding, however, are less fit than the parents. That makes it advantageous for parents to ensure more offspring will survive by developing distinguishing characteristics, such as male wing color, and thereby avoiding the costly mistake of mating outside their own species.

"The fact that the hybrids are less viable drives the divergence between the parent species," Pierce said. "Wing colors must be one of the first traits the butterflies use to recognize the right mate."

The research was published in the July 21, 2005 issue of the journal Nature.

Zoologist says in animal kingdom, less is more

70652986 — Mon, 26 Mar 2007 05:41:22 -0400

Harvard researcher Piotr Naskrecki hopes his new book, "The Smaller Majority" (Harvard University Press, 2005), will win over some new advocates for the tiny creatures he has spent his life studying. It is a gorgeous book, featuring hundreds of photographs from Naskrecki's expeditions in Latin America, Africa, Australia, and the South Pacific.

Naskrecki has trained his macro lens on some of the rarest and most unusual living creatures on the planet. Some of them are still unclassified and, until now, unphotographed. And while some of the reproductions may show a tiny ant or spider enlarged to many times its original dimensions, Naskrecki says that his real aim is not to confer the gift of size on his tiny subjects.

"In my photography, I'm not trying to make them bigger.

Ivory-billed woodpecker: Ornithology's holy grail

50443248 — Fri, 20 Jul 2007 12:38:38 -0400

Tim Gallagher and Bobby Harrison almost flopped into the mud of Arkansas' Bayou de View in their haste to get out of the canoe. They crashed through the undergrowth after the flashing black and white bird that was threatening to vanish among the huge cypresses.
After dashing across the soggy ground, through brambles, and over fallen logs, the bird finally disappeared. Gallagher stood stunned. Harrison fell down on a log, overcome by emotion.

"I saw an ivory-bill!" he said.

After a half-century of apparent extinction, in February 2004 the ivory-billed woodpecker came back to life.

Chimp genome effort shines light on human evolution

70652986 — Mon, 26 Mar 2007 06:21:59 -0400

A research effort, led by scientists at the Broad Institute of MIT and Harvard, the Washington University School of Medicine in St. Louis, and the University of Washington, Seattle, focused on the chimpanzee in hopes that genetic comparisons with humanity's closest relative will lead to answers to both practical questions - such as the causes of human disease - and to more fundamental questions on human biology.

In addition to their obvious physical differences, humans and chimpanzees have different responses to Alzheimer's disease, malaria, and HIV/AIDS, for example.

"We're focusing on the differences as a way to shed light on ourselves," said Eric Lander, Broad Institute director and professor of systems biology at Harvard Medical School, who led the project along with Richard Wilson of the Washington University School of Medicine in St. Louis and Robert Waterston of the University of Washington, Seattle. "This is a case where evolutionary analysis is a direct handmaiden to biomedicine."

Among the 3 billion base pairs in the DNA of both humans and chimpanzees, researchers found differences in 40 million sites. It is in those sites where the differences between the two species lie.