Lions'taste for human flesh dissected: Nature Newsa notorious pair of man-eating lions that teamed up to terrorize Kenyan labour camps more than 100 years ago did not have the same taste for human flesh,
a new study suggests. The findings may reveal unexpected flexibility in lion social relationships. Between March and December 1898, a pair of male lions killed
and devoured 28-135 people in the Tsavo region of Kenya. To understand what happened, Justin Yeakel, an ecologist at the University of California, Santa cruz,
and his colleagues analysed the lions'remains. The team found that the pair probably consumed about 35 human victims
with one of the animals devouring the lion's share, while the other stuck to a more traditional diet.
We would expect that if they're within a cooperative coalition, they would be consuming similar things,
This shows that lion behaviour is even more flexible and complex than we originally thought. It is the first time that different food preferences have been seen within one coalition of social carnivores.
The team reports its findings in Proceedings of the National Academy of Sciences. 1 Lions normally dine on grazing animals such as zebra and wildebeest
but in 1898, drought, pestilence and hunting left the Tsavo region of Kenya barren of the lions'favourite meals.
The lions dragged people from tents at night, killing 28 labourers and an unknown number of native Taita estimates range from none to 107.
Yeakel analysed the ratios of carbon isotopes in the lions'tissues, which should reflect the isotope ratios of their prey.
Browsing animals, such as giraffes and antelopes, have different ratios of carbon isotopes to grazers because their food shrubs and trees versus grasses carries out different types of photosynthesis. The team characterized the humans'isotope ratios by taking advantage of a fluke of history,
The lions'remains gave Yeakel two time windows of food preferences: the last 2-3 months of the animals'lives, obtained by analysing the quickly regenerating tail tuft hairs,
which prey combinations were most likely to produce the lions'isotope ratios. The results show that for most of their lives,
over the 9 month period, the lions probably consumed around 10.5 and 24. 2 humans, respectively,
Dominy says that lions may team up for territorial defence2, but such extreme dietary specialization in a cooperative group has not been seen before.
Apart from the environmental pressures on the lions, the dominant maneater also had severe wounds in his mouth and jaw,
which makes it difficult to extrapolate to other lions. Stanley Ambrose, an anthropologist at the University of Illinois in Urbana-Champaign, is wary of the conclusions.
As a result, a wide range of proportions of available prey items could account for the lions'isotope ratios,
works with mouse models of muscular dystrophy at Ohio State university in Columbus. She declined an interview request.
Mystery of the brown giant panda deepens: Nature Newspandas are endangered increasingly in the wild, and the sighting of one with extremely rare brown-and-white fur is now raising fears that the species may be suffering from inbreeding.
In November 2009, a staff member at the Foping Nature Reserve in China's Qinling Mountains one of the panda's last remaining strongholds spotted a panda with the unusual colouring.
Wang and his Twente colleague Andrew Skidmore are concerned that the brown-and-white form indicates that breeding between closely related pandas is becoming more common.
Each panda has two versions, or alleles, of each of its genes, one inherited from its mother and one from its father.
Wang suggests that the Qinling pandas carry a dominant gene for black fur and a recessive gene for brown fur.
This means that pandas with brown-and-white fur are only possible when they inherit the recessive brown gene from both mother and father.
if the pandas were related closely. The habitat in the Qinling Mountains is fragmented seriously and the population density is very high,
The brown pandas could be an indication of local inbreeding. Conservationists worry about such inbreeding because it means that more animals rely on the same set of genetic defences to overcome environmental threats,
According to Wang, brown-and-white pandas have only been seen in the Qinling population, one of five mountain regions where pandas still live in the wild.
Qinling is home to around 300 animals, roughly one-sixth of the total panda population in the wild.
The first recorded brown-and-white panda a female called Dan-Dan was discovered in 1985.
She was taken into captivity mated with a black-and-white animal and gave birth to a normal black-and-white male.
A few years later, another brown-and-white panda was seen in the wild, together with its black-and-white mother.
who has studied the morphology and genetics of the Qinling pandas. But there could be other factors at play,
although most of the Qinling pandas appear to be normal black-and-white animals, many of the region's pandas do have touches of brown in their chest fur1.
This suggests that there could be something specific to Qinling, such as the climate or a particular environmental chemical, that affects one
The Qinling Mountains have shaped brown subspecies of other mammals, such as the golden takin, he notes.
which show that despite a dramatic contraction of the panda's range over the past few thousand years,
the remaining giant panda populations seem to have retained a lot of genetic diversity2. The evidence that giant pandas in general,
and in the Qinling Mountains in particular, are of low genetic variation is at best equivocal, says Mike Bruford, a molecular ecologist at Cardiff University, UK,
The giant panda genome, which was published online in Nature last month3, also revealed little sign of inbreeding, says Jun Wang of the Beijing Genomics Institute in Shenzhen, China.
But the genome is likely to prove invaluable for solving the mystery of the brown pandas of Qinling.
There are over 125 genes known to affect pigmentation in mice says Hopi Hoekstra, an evolutionary biologist at Harvard university in Cambridge, Massachusetts,
and an expert on pigmentation in mammals. There are definitely a good handful of candidate genes you could sequence in the two morphs
A comparison of brown and black pandas at Qinling and other sites should shed light on the genetic basis of this rare variety,
Carbon credits proposed for whale conservation: Nature Newsbiological oceanographer Andrew Pershing wants carbon credits for whale conservation.
That's because whales, he says, are like trees. Like any animal or plant, they are made out of carbon.
And whales are so big they each store a lot of carbon, he says. Pershing, of the University of Maine in Orono and the Gulf of Maine Research Institute in Portland, Maine, calculates that
even though some whale species are now recovering from the effects of factory whaling, total whale biomass today is less than one-fifth of
what it was in 1900, before whaling decimated the population. Letting the whale population recover
he said on 25 february at the American Geophysical Union's 2010 Ocean Sciences meeting in Portland,
Oregon, could eventually sequester 9 million tonnes of carbon in their combined biomass. He compares it to planting trees.
Whales take carbon out of the system through their food, then incorporate that carbon in their tissues.
You're taking whales out of the population and putting their carbon somewhere else. In the early days of whaling
the carbon is released through the consumption of whale meat by humans, but you're still taking carbon out of the whale
and putting it into something that's going to respire it. Furthermore, when whales die naturally,
they usually sink to the bottom of the ocean, carrying their carbon with them. Back in 1900,
when whale numbers were high, that would have totalled about 200,000 tonnes of carbon per year, Pershing estimates.
Even though benthic creatures eventually eat the whale carcasses (see'Bone-devouring worms discovered), 'the carbon will remain in the depths,
If whales increase in numbers, other species that compete for the same food might decline.
there could still be a substantial increase in total biomass owing to the difference in size between whales
any given food source (such as krill) can support a lot more biomass in a whale than in a small animal such as a penguin.
Santa cruz. It means that whales are important not just because they're charismatic, but because they play an important role in the carbon cycle.
Pershing's research may actually understate the degree to which whales could sequester carbon. The iron in whale faeces is an important micronutrient that is often in short supply in waters such as the Southern Ocean,
and it can help boost algal growth which ultimately means more food for everything, including whales.
In order to drive these large algal blooms you need iron says Costa. In fact, he says, the indirect benefits of iron fertilization from whale faeces might remove more carbon from the atmosphere by boosting algal growth than the growth of the whales themselves.
Pershing adds that the same analysis applies to other large ocean animals whose populations have been reduced drastically, such as bluefin tuna and some species of shark.
or early 2012 at a total cost of under $0. 53 per litre roughly on a par with that of'corn'ethanol produced from sugar-rich maize cobs.
Awards Wolf winners: Physicists Anton Zeilinger, John Clauser and Alain Aspect share the prestigious 2010 Wolf Prize in Physics for their work on quantum entanglement.
Biologist Axel Ullrich took the medicine prize for his research in cancer (he co-developed trastuzumab,
) Pika not protected: The US Fish and Wildlife Service has denied endangered-species protection to the American pika (Ochotona princeps.
Campaigners had argued that the small herbivore (pictured) would be threatened by rising temperatures. It would have been only the second mammal other than the polar bear to be afforded such protection explicitly because of climate change.
Federal biologists said that pika, which live in mountainous parts of ten western US states, would be able to migrate
or adjust to warmer climes. Cloud access: The US National Science Foundation (NSF) announced on 4 february that selected NSF-supported researchers would be given access, via three-year agency grants,
The lion's share of that funding comes from financial donors that include government agencies in the United states and United kingdom,
they are talking about apples and oranges and Porsches and whales and moons, he says.
People go out into the woods at night with dogs and pigs to locate them there's folklore behind it.
Nature Newstop elephant scientists are up in arms over the prospect of elephant-poaching hot spots in Africa being allowed to sell off their ivory stockpiles.
Despite the two nations'poor track records in elephant protection, conservationists are worried that the proposals could be accepted because of an ongoing CITES debate over how best to manage elephant populations.
and ignore the reality of the burgeoning demand from the middle classes in Asia for ivory products such as seals and ornamental tusks.
and more than 20 other elephant researchers argue for a bigger role for science in CITES decisions about elephant conservation.
Some countries'elephant-monitoring data is not publicly available until the CITES meetings are in session,
In their petitions, Zambia and Tanzania both state that their elephant populations are healthy and growing.
They say that downgrading the endangered status of their elephants to allow the sale of ivory,
will actually help to protect elephant populations by providing authorities in the countries with cash to put appropriate measures in place.
But scientists are wary about the elephant numbers being quoted by Tanzania and Zambia. Wasser says DNA analyses of major ivory seizures have shown that several tonnes of ivory intercepted in Asia during the past few years originated in the two countries2.
Several other scientists working in the region have misgivings about the accuracy of Tanzania's latest elephant census last year.
and peer review, says Iain Douglas-Hamilton, founder of Save the Elephants, a nonprofit organization that is headquartered in London but works mainly in Kenya.
The Kenya Wildlife Service (KWS) shares three distinct populations of elephants with the Tanzania National parks,
In January, Kenya led the African elephant Coalition a group of more than 20 African nations opposed to the ivory trade in meetings in Brussels to lobby the European union against the Tanzanian and Zambian proposals.
Nature Newsa study of sexually scrambled chickens suggests that sex in birds is determined in a radically different way from that in mammals.
This cell-by-cell sex orientation contrasts sharply with the situation in mammals, in which organism-wide sex identity is established through hormones.
because nothing like them has been seen in mammals. In almost all mammals, including humans, embryonic cells are initially sexually indistinguishable.
During development, genetic factors trigger the formation of male or female gonads according to an animal's combination of sex chromosomes (XY for males and XX for females.
Clinton says the work shows that chickens have a fundamentally different way of determining their sex from mammals:
but nowhere near the extent seen in mammals. He suspects that the same rules apply to other species of bird,
this study strongly suggests that birds follow a different developmental pattern from mammals, agrees behavioural neuroscientist Juli Wade at Michigan State university in East Lansing who works on sexual differentiation in the songs of zebra finches2.
Birds aren't the only exception to the rule. The mammal model also fails with some marsupials and invertebrates like fruitflies.
The problem is once people develop a hard and fast rule, it becomes the only game in town,
but that has become a political nonstarter. Last year, the commission attempted to force France, Greece,
In the 1000s, for example, the'Book of Settlements'a medieval manuscript containing details of Iceland's settlements reports a famine so severe men ate foxes
is harboured in mammals, birds and even insects. It can trigger abortions in goats and sheep and causes flu-like symptoms and sometimes pneumonia in humans.
The french agricultural research institute, will start by looking at how the bacteria spreads in mice.
The CVI said that starting this year they will also monitor the incidence of the disease in pets and horses.
Cats, for example, have been identified as a vector in Canada and Japan. We need to know a lot more about the disease to understand why it's so different in The netherlands than the rest of the world,
Nature Newsa bacterial protein used in a common pesticide kills intestinal parasitic roundworms in mice and may become a treatment option for humans,
The parasitic worm Heligmosomoides bakeri naturally infects mice and is a common laboratory model organism for studying human diseases caused by roundworms, such as river blindness and elephantiasis.
The researchers orally infected mice and waited for the parasites to mature and become reproductively active adults before treating the mice with the crystal protein.
A few days after treatment, the mice had 98%fewer parasite eggs in their faecal samples
and 70%fewer adult parasites in their intestines compared to untreated mice. Aroian's previous study2 using a type of human intestinal roundworm parasite to infect hamsters showed a 90%reduction in three doses of Bt.
Taken together the two in vivo studies have shown significant therapeutic activity of a crystal protein against two species of nematode,
says Andrew Kotze from the livestock industries division of Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) in St lucia, Queensland.
Aroian hopes that these mouse and hamster studies will pave the way to human trials within two to four years.
Nearly all of the current drugs to treat nematode diseases were invented for veterinary purposes, he says,
including walrus and beluga whales. The review, by scientists at the US Geological Survey, will be completed by 1 october 2010.
Ardi may be more ape than human: Nature Newsa fight has broken out over attempts to drag'Ardi'-the oldest hominid skeleton found-out of the woods where her discoverers say she lived.
whether the species found in the Rift valley of the Afar of Ethiopia is an ape or hominid.
but not knuckle-walking like a chimpanzee. While the opposing points of view are being argued vigorously this week in Science,
the small-mammal fossils present; and the types of silica-rich plant remnants called phytoliths.
The Cerling group contends that the abundance of small-mammal fossils at the site which White's group says supports a woodland environment could be due to predators hiding in vegetation growing around water
because the fossil probably predates the divergence between humans and apes, which he estimates as 3 to 5 million years ago2.
whether she is in the ape or human lineage, says Sarmiento, who conducts research from home in East Brunswick,
The week ahead 20-22 may Mouse models of autism are one of the items on the agenda at the international meeting for autism research
This will allow us to protect the most intact parts of the boreal forest that are critical habitat for the caribou and other species
This is good news for caribou, whose numbers in Canada have been in steep decline. But it may also slow down global warming
But I don't ride horses any more, she says. She also spends her days organizing her life's papers and memorabilia in the three-story family home,
a conservation biologist at James Cook University in Cairns, Queensland, Australia, and one of the authors of the analysis, to be published in the journal Conservation Letters1,
A nonprofit watchdog filed a lawsuit on 16 august to stop the construction of a US$4-billion weapons facility at Los alamos National Laboratory in New mexico.
The number of B. napus plants in each sample plot was counted and one plant was collected
The team found B. napus at nearly half of the 288 sites tested. Of these, 80%had at least one herbicide-resistant transgene (41%were resistant to Roundup and 40%resistant to Liberty.
Nandula Raghuram of the Society for Scientific Values, an ethics watchdog based in Delhi says that what should have been a rigorous assessment by India's top scientific institutions has ended up as the mouthpiece of Ananda Kumar,
Like Hawlena's grasshoppers, the elk of Yellowstone national park in Wyoming were thought to eat differently because of the threat of predation.
Some researchers proposed that the return of wolves to the park would cause elk to begin avoiding certain'risky'areas containing the predators.
That in turn would allow aspen trees munched into submission by the elk to begin growing back in those areas.
wolves could have a huge effect on the landscape. Alas not according to a recent study by Matthew Kauffman of the US Geological Survey in Laramie, Wyoming,
Tree rings and fenced-off experimental areas revealed that aspen growth didn't track well with wolf presence or absence.
The elk do change their behaviour in response to wolves and do avoid risky areas in general just not often enough to change the picture for aspen.
because elk that are near starvation as many often are in the winter are willing to take any risk to eat.
to say'to hell with wolves 'and feed there for a few days, says Kauffman. It remains to be seen
But that fact means ancient RNA might not be very useful for studying ancient animals such as mammoths.
has eclipsed the US Department of energy's Jaguar system at the Oak ridge National Laboratory in Tennessee. In the latest update to the list of the world's top 500 supercomputers (www. top500. org), released on 11 november,
with Jaguar managing 1. 75 petaflops. The United states still boasts five of the world's top ten fastest computers.
Ape deaths solved Japan's premier primate research centre says it has identified the cause of the mysterious series of deaths of its Japanese macaques (Macaca fuscata) that had puzzled researchers
) The Primate Research Institute of Kyoto University reported on its website on 11 november that the culprit was simian retrovirus-4 (SRV-4). The problem emerged
when the institute housed southeast Asian crab-eating macaques (Macaca fascicularis), which are natural carriers of the virus, with Japanese macaques.
The report said the virus had never been passed to humans. Events Cholera in Haiti The escalating cholera epidemic in Haiti had claimed more than 900 lives
on 16 17 november. go. nature. com/prqng2 21 24 november Officials from 13 countries with wild tiger populations meet at a global summit on conservation of the species in St petersburg, Russia
unlike the mouse version, it develops symptoms similar to those seen in humans with the disease, such as infection and inflammation in the lungs.
including widely used laboratory animals such as fruitflies and mice. It banned the breeding of any GM organism
African elephants are two distinct species: Nature Newsafrican forest-dwelling elephants (Loxodonta cyclotis) are a separate species from those living in the African savanna (Loxodonta africana),
researchers have shown. Scientists have debated long whether African elephants belong to the same or different species. They look very different,
with the savanna elephant weighing around 7 tonnes roughly double the weight of the forest elephant.
But studies had suggested they were the same species DNA in mitochondria (the cell's energy factories) from African elephants found evidence of interbreeding between forest and savanna elephants around 500,000 years ago2.
Now a group of scientists have taken a deeper look at the African elephants'genetic ancestry. The researchers sequenced the nuclear genomes of both types of African elephant
as well as that of the Asian elephant (Elephas maximus). ) They also extracted and sequenced DNA from the extinct woolly mammoth (Mammuthus primigenius) and mastodon (Mammut americanum) ancient elephant ancestors.
By comparing all these genomes, the team found that the forest and savanna elephants diverged into separate species between 2. 6 and 5. 6 million years ago.
The study is published online in the journal Plos Biology1. They split about the same time as African and Asian elephants split into separate species,
and much longer ago than people previously thought, says David Reich, a population geneticist at Harvard Medical school in Boston,
Massachusetts, and a lead author on the study. You can no more call African elephants the same species as you can Asian elephants and the mammoth,
he adds. Most researchers agree that the Asian elephant and the mammoth are separate species,
says Thomas Gilbert, a geneticist at the University of Copenhagen. But this study really hammers the coffin shut on any arguments that the forest
and savannah are anything but different species, or even genera, he says. MITOCHONDRIAL DNA can only give researchers information on maternal ancestry,
as this genetic material is inherited solely from the mother. Examining the nuclear genome which is around 200,000 times larger than that contained in mitochondria,
gives a broader and more accurate picture of elephants'history. You get a different picture by looking at nuclear DNA,
and savanna elephants interbred recently and had shared a recent female ancestor can be explained as a result of the female elephant's social behaviour,
the researchers say. Females tend to stay close to their place of birth, while the males roam. Herds of female forest elephants could have repeatedly come into contact
and bred with migrating male savanna elephants. Over a long period of time the forest elephant gene pool would become diluted
and displaced by that of the savanna elephants, but the forest DNA would be conserved in the MITOCHONDRIAL DNA,
which is passed on through the female line. What we see is an ancient split with a bit of gene flow more recently,
he says. Hybridization happens between closely related animals and does not necessarily imply that the two are the same species,
The authors suggest that the findings will help to reprioritize elephant conservation programmes. All African elephants are conserved currently as the same species
. But the evidence that they are two distinct species suggests that they may be facing different pressures
The forest elephants should become a greater conservation priority, the study says.
Tide turns against corn ethanol: Nature Newsbuffeted by the economic crisis and a drop in the oil price,
Seals threatened Two Alaskan seal species may become the first animals since the polar bear in 2008 to be listed as'threatened'under the US Endangered Species Act because of climate change.
On 3 december, the National Oceanic and Atmospheric administration proposed adding Arctic ringed seals (Pusa hispida) and Pacific bearded seals (Erignathus barbatus) to the threatened list
citing diminished sea ice in their native habitats. The final decision will be made after a period of 60 days to allow public comment;
Bulfone-Paus bears substantial responsibility for the postdocs'scientific misconduct, the committee charged. See go. nature. com/ik1pgp for more.
Nature Newsevolutionary advantage often makes for show-stopping stuff a cheetah's speed, for example, or a moth's almost perfect mimicry of tree bark.
Nations pledge to double tiger numbers Thirteen countries that are home to the world's last wild tigers have pledged to try to double the animal's numbers to about 7
000, and to significantly expand its habitat by 2022 (the next Chinese year of the tiger.
and a loan package from the World bank for some tiger-range countries. One of the challenges will be to prevent poaching
and trade in tiger skins (pictured 墉 a seized skin in Kolkata, India). US energy boost The United states needs to triple its annual federal funding 墉 from US$5 billion to $16 billion 墉 for energy'research, development, demonstration and deployment,
Polar-bear pad The US Fish and Wildlife Service has set aside roughly 484,000 square kilometres in Alaska and the surrounding seas as a'critical habitat'for the polar bear (Ursus maritimus),
more than two years after the species was given a protection status of'threatened'by the US Endangered Species Act.
but federal agencies have to ensure that proposed activities don't jeopardize polar bears and their habitat.
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