Unlikely Cousins: Whales And Hippos

If the idea of whales being mammals has always seemed a bit wild, then you’ll probably be surprised to learn that the giant aquatic beasts are pretty closely related to the hippopotamus.

Scientists have been wrangling over these relations for centuries.

One theory had been that hippos were related to pigs. Yet mounting evidence suggested they are closer to whales. A new study concludes that a four-footed semi-aquatic mammal that thrived for some 40 million years was a common ancestor to both whales and hippos.

“The problem with hippos is, if you look at the general shape of the animal it could be related to horses, as the ancient Greeks thought, or pigs, as modern scientists thought, while molecular phylogeny shows a close relationship with whales,” said Jean-Renaud Boisserie, a post-doctoral fellow at the University of California, Berkeley. “But cetaceans – whales, porpoises and dolphins – don’t look anything like hippos.”

To complicate matters, there is a 40-million-year gap between fossils of early cetaceans and early hippos.

Boisserie and colleagues in France say they’ve filled in the gap with fossils of a “water-loving animal” that evolved into two groups, early cetaceans and a group of four-legged animals called anthracotheres. The pig-like anthracotheres, which developed at least 37 distinct genera, died out less than 2.5 million years ago, leaving only one line: the hippopotamus.

The analysis puts whales within a large group of cloven-hoofed mammals called Artiodactyla. That makes them relatives of cows, pigs, sheep, antelopes, camels and giraffes, too.

The idea of whales and hippos being related has gained steam in recent years. Boisserie’s team analyzed new and previous hippo, whale and anthracothere fossils to pin down anthracotheres as the missing link between hippos and cetaceans, they say.

“Our study is the most complete to date, including lots of different taxa and a lot of new characteristics,” Boisserie said. But leaving the case not quite shut, he added: “Our results are very robust and a good alternative to our findings is still to be formulated.”

1 Ton Of Illegal Ivory Will Be Publicly Destroyed In Nyc Friday

In a public display against elephant poaching, U.S. officials will pulverize a huge store of illegal ivory tomorrow (June 19) in Times Square, in the heart of New York City.

To staunch the demand for elephants' tusks, officials from federal, state and nonprofit organizations are scheduled to destroy more than 1 ton of confiscated ivory.

"The scale of the crisis has gotten to the point where 35,000 [African] elephants are killed every year — 96 a day," said John Calvelli, executive vice president of public affairs for the Wildlife Conservation Society (WCS). [In Photos: US Destroys Its Elephant Ivory]

Calvelli, and other representatives from government and nongovernmental agencies, will speak at the event, which is scheduled to begin at 10:30 a.m. EDT in Duffy Square-Broadway Plaza in Times Square. Following the speeches and presentations, the ivory will be crushed into powder and fragments for the public to witness.

"Times Square is the crossroads of the world," and is always filled with people from different countries, Calvelli said. "What happens in Times Square gets amplified around the world."

Illegal ivory

The ivory stockpile mostly came from an undercover operation conducted by the U.S. Fish and Wildlife Service (FWS) in Philadelphia in 2009, Calvelli said. Gavin Shire, chief of public affairs for the FWS, said most of the confiscated pieces are large carved statues and tusks. Additional ivory came from busts made by the New York State Department of Environmental Conservation, including one in 2012 that resulted in $2.4 million worth of ivory being confiscated and that carried a $50,000 penalty, Calvelli said.

The only other ivory crushing in the U.S. was held in Colorado in November 2013, during which more than 6 tons of ivory was destroyed. The act spurred crushes in countries around the world, including France, Belgium, China, Hong Kong and the Philippines.

Since 1989, 13 nations, including six African countries, have burned and crushed almost 150 tons of confiscated ivory, representing slightly more than 13,600 elephants, according to the WCS's "96 Elephants" initiative, named for the 96 elephants killed every day in Africa.  

Wild elephants

There are two species of elephant: the African elephant (Loxodonta africana) and Asian elephant (Elephas maximus). The Asian elephant was listed as an endangered species in 1976, and commercial trade of the animal and its parts is prohibited under federal law.

African elephants tend to be bigger and have larger tusks than their Asian counterparts, and were listed as a "threatened" species in 1978, which means the species is likely to become endangered if no interventions are put in place. From around 1980 to 1990, the African elephant population decreased by almost 50 percent. In 1989, the federal African Elephant Conservation Act put a ban on the import of African elephant ivory to the United States from any country, unless the elephant was killed before 1989.

To get around this embargo on younger ivory, Calvelli said that poachers and traders rub coffee on ivory and bury pieces for significant stretches of time to pass them off as antiques with "wear and tear."

Furthermore, determining the age of an ivory bracelet or statue is complicated, Calvelli said. Elephants in the wild typically live 30 to 50 years, but to accurately assess the age of an ivory trinket, the material would have to come from the root of the tusk. Just like human hair, the farther the distance from the point of growth, the older the material is.

"Elephants don't grow on trees," Calvelli said, noting that once an elephant is killed and its tusks are removed, the animal is often left to rot where it was found. [In Photos: Endangered and Threatened Wildlife]

Sending a strong message

Instead of crushing the ivory, some members of the public have suggested that the government should sell it to raise money for conservation. However, Shire said that selling ivory is illegal and would send a message that the poached ivory has value.

After the confiscated ivory is crushed in Times Square, it will be added to the 6 tons of crushed ivory in Colorado, Shire said. Earlier this year, the FWS asked the public for ideas on what to do with the ivory dust. The only stipulation was that any sort of structure made from the ivory should carry a strong message to stop wildlife trafficking and the illegal ivory trade, ultimately in hopes of squelching demand for the material. The FWS was interested only in creations that would not imbue the ivory with any value, whether artistic or monetary, Shire said. "The aim was to show that ivory has no value when it's not on an elephant," Shire said. 

The FWS is currently reviewing possible ideas, and plans to announce a winner in the near future.

The FWS is leading the "Ivory Crush at Times Square" event, with support from organizations like the Wildlife Conservation Society and New York State Department of Environmental Conservation, among other groups. 

Elizabeth Goldbaum is on Twitter. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science

Bizarre Survival Tactic: Gazelles Shrink Heart To Beat Heat

In an extreme way to beat the heat, a sand gazelle shrinks its liver and heart to cope with long periods of drought, a new study reveals.

The deserts of the Arabian Peninsula rank among the most severe environments in the world. It's extremely hot and unpredictable rains do little to quench the arid land.

While some of the region's animal inhabitants struggle under these conditions, the sand gazelle stands out as one of the most successful critters at dealing with this stress.

"We found that gazelles had the lowest total evaporative water loss ever measured in an arid zone ungulate [hoofed animal]," write the team of researchers from Ohio State University and the National Wildlife Research Center in Saudi Arabia.

Organs such as the liver and heart require significant amounts of oxygen to function. By shrinking these organs, the gazelles don't have to breathe as much and thus reduce the amount of water lost by respiratory evaporation.

Water-deprived sand gazelles also have a higher fat content in their brains. The researchers suggest that these stores might be beneficial for fueling brain metabolism during prolonged food and water deprivation.

The study, announced today, was published online May 19 in the journal Physiological and Biochemical Zoology.

Do Animals Have Menopause?

Human women typically go through menopause between ages 45 and 55, when they undergo hormonal changes that cause them to stop being able to reproduce. But they're not the only ones in the animal kingdom who live beyond their reproductive years.

Scientists have long known that animals' fertility and reproductive success slowly decline with increasing age — a phenomenon called reproductive senescence. But, for the most part, reproduction in animals seems to continue up to old age and death, though at a diminished capacity.

In a recent review of primate species, researchers found that humans are the only primates that don't die within a few years of "fertility cessation." And this is true even when modern medicine and health care are taken out of the equation, as the study included data from the hunter-gatherer !Kung tribe in the Kalahari Desert.

In the past couple of decades, however, numerous studies have claimed that menopause, or "post-reproductive life spans" — a phrase that most often refers to the age of last reproduction, since changes in ovulation and hormones related to menopause are difficult to measure in wild animal populations — occurs in a wide range of species. Guppies, for instance, appear to go through a fish version of menopause, according to one study, which found that the fish spend an average of 13.6 percent of their total life spans in a post-reproductive stage.

In fact, such "menopause" appears somewhat common among fish, birds, mammals and invertebrates (animals without backbones), according to a recent review on the topic published in July 2015 in the journal Trends in Ecology & Evolution. Yet, there's a major caveat to this statement: For the vast majority of species, the animals don't live long after they stop reproducing, and menopause appears to be a circumstance related to captivity (such as in the guppies) that occurs only in some individuals, not the entire species.

But there are exceptions. Among vertebrates, two species of toothed whales live long lives after menopause. Female killer whales reproduce between the ages of 12 and 40 years but can survive into their 90s, while female short-finned pilot whales reproduce between the ages of 7 and 35 and live past 60.

Also in this select group are some insects, such as the gall-forming social aphid Quadrartus yoshinomiyai, in which adult females have extended post-reproductive livesdefending the colony.  

From an evolutionary standpoint, menopause is an apparent oddity, given that you'd expect individuals to want to pass on their genes for as long as possible. So why did it develop at all?

The most prevalent theory behind menopause is called the grandmother hypothesis. In short, it suggests females may stop breeding early to help their children and grandchildren survive and reproduce. This certainly appears true in orca populations, in which older females are repositories of ecological knowledge, especially when it comes to finding food — researchers found mothers increase the survival rate of their adult sons, which have better reproductive success the older they get.

Interestingly, matriarch elephants are also vital in the community, but they don't go through menopause.

The difference here lies in how the groups are made up. Killer whales' sons and daughters stay in the groups in which they were born. So, over time, the mothers become increasingly related to their neighbors, providing a motive to shift from reproducing to helping their descendants, thus further enhancing their genetic legacy. In elephant society, on the other hand, sons leave the birth group, so mothers don't become any more related to their group mates as they age.

Another key aspect of this is competition for resources.

Research in orcas shows that when two generations of killer whales in the same group breed simultaneously, calves from the older generation of females are 1.7 times more likely to die. This is possibly because younger females are focused only on their calves, whereas the older females may raise their own children and those of their adult daughters.

In ancestral humans, daughters would move out to join new families. A daughter would initially have no relation to the group until she had children, but as she got older, she would become increasingly related to her group. Eventually, helping her relatives raise their children would become more genetically beneficial to her, especially since having more children would put her new kids in direct competition for resources with her other descendants. 

Originally published on Live Science.

Humans Have Cracked The Secrets Of Uncrackable Parrotfish Teeth

Have you ever dug your feet into the warm, soft surface of a white sand beach? Felt the fine, dry grains slide pleasurably between your toes? Thank a parrotfish. Specifically, thank it for its poop. Most of the sand on just about every white beach in the world is the product of generations of the strange family of fish digging their sturdy beaks into ocean-floor coral and chewing chunks of rocky organic matter down to powder. And now, researchers know how the swimming weirdos get through their stony meals without cracking their teeth.

A team of scientists from Lawrence Berkeley National Laboratory, Nanyang Technological University in Singapore and the University of Wisconsin-Madison subjected parrotfish beaks to a Berkeley X-ray machine known as the Advanced Light Source (ALS). The ALS can image organic crystals at a microscopic level. And the analysis revealed a unique woven structure in the crystals in a parrotfish's mouth that could open new frontiers for materials science, the researchers said.

"Parrotfish teeth are the coolest biominerals of all," Pupa Gilbert, a UW-Madison physicist and lead author of the study, said in a statement. "They are the stiffest, among the hardest, and the most resistant to fracture and to abrasion ever measured." [See Photos of the Bizarre Bumphead Parrotfish]

"Stiffness" and "hardness" may sound like synonyms, but they have different meanings in engineering. A stiff object isn't very elastic. Press on it, and it won't bend; pull your finger away, and the material won't bounce back. A hard object resists permanent damage; bash it against a wall, and it won't dent or deform.

The record-stiff, superhard teeth of parrotfish apply enormous force — 530 tons of pressure per square inch — to their coral meals. And those teeth don't break or fall out of the animals' mouths.

And yet, there isn't anything all that chemically interesting about parrotfish teeth, the scientists said. Look at them under a microscope, the researchers explained in their statement, and you'd struggle to differentiate the material from the enamel found in the mouths of all kinds of animals.

Parrotfish have about 1,000 teeth arranged in 15 rows, with new teeth constantly bursting from the soft tissue to replace old ones. That's not all that unusual; many sharks have a similar setup. But parrotfish are unique in the way their legions of teeth fuse together to form their hard beaks.

The real astonishing structure of parrotfish beaks, though, is much smaller, as the researchers said in a paper published online Nov. 15 in the journal ACS Nano.

On the micro scale, the enamel fibers' diameters narrow from an average of 5 microns (5 thousandths of a millimeter) at the bases of the teeth to 2 microns (2 thousandths of a millimeter) near the tips. And the fibers weave together like tight fabric out of a loom, warp and weft aligned at right angles to one another.

That structure, like the one likely holding your shirt together but spun from hard organic crystals, gives parrotfish the superpower of chewing on rock-hard, brittle corals the way you'd bite into a loaf of bread.

Researchers said they might be able to mimic the micro-structure to build synthetic materials for human use. Imagine a set of tools capable of surviving the grinding pressure of 530 tons per square inch against rough, hard coral. It's the biological technology behind every white beach in the world. Who knows where it will go next?

Original article on Live Science.

Gorillas Play Tag Like Humans

Gorillas apparently can play tag much like humans do, scientists now reveal.

These hit-and-run games suggest that gorillas, like humans, will do what they can to get the upper hand.

To study play-fighting among gorillas, scientists analyzed videos of 21 of the apes from six colonies in five European zoos collected over the course of three years.

In their games, "not only did the gorillas in our study hit their playmates and then run away chased by their playmates, but they also switched their roles when hit so the chaser became the chased and vice versa," said researcher Marina Davila Ross, a behavioral biologist at the University of Portsmouth in England. "There are a lot of similarities with the children's game of tag."

During the games, the gorillas showed open-mouthed playful faces as they chased those who hit them. Hard hits resulted in chases more often than soft grabs, which were often ignored.

Instead of letting what might be a fair trade of blows happen, these hit-and-run games were shows of relatively unfair behavior, where the gorilla who starts the game tries to get away with tagging a fellow playmate without getting hit in return. Such games likely help the apes — and humans — learn how to deal with real conflict by testing what is acceptable with a safe crowd of peers and even parents, Davila Ross said.

Role-playing as chaser and the one being chased could also help apes sharpen their communication skills, according to the researchers.

The researchers said this was the first study to systematically analyze how apes respond to unequal situations in a relatively natural setting — previous studies have all been carried out in laboratories.

Still, "I don't think this is a gorilla-specific behavior — I think it's very likely present in various species," Davila Ross told LiveScience. "Chimpanzees and gibbons might also do it."

The scientists detailed their findings online July 14 in the journal Biology Letters.

Endangered Tigers Find A Wild New Home

Kazakhstan has announced plans to open its arms to a group of oversized, furry immigrants from neighboring Russia — endangered Amur tigers.

A vast land of sprawling steppes (the flat and open land that covers huge swathes of central Asia), Kazakhstan was once home to Caspian tigers, one of the nine tiger subspecies, but the big cats disappeared from the central Asian country — at the time a Soviet republic — in the late 1970s, driven to extinction by poaching and loss of habitat.

Kazakhstan government officials expressed interest in reintroducing tigers to their country in March, to representatives of the conservation organization WWF, and representatives from the group's Russia branch say a plan is in the works.

"We have agreed that WWF and the Ministry of Environment in Kazakhstan will draw up a comprehensive program to reintroduce the tiger in the area around Lake Balkhash," said WWF-Russia director Igor Chestin in a statement. "With a strong plan and proper protections in place, tigers can again roam the forests and landscapes of Central Asia."

Researchers believe Amur tigers are well-suited to thrive in the region, which possesses roughly 1 million acres of suitable tiger habitat, according to recent investigations.

Recent genetic research, conducted by sequencing DNA collected from museum specimens of extinct Caspian tigers, revealed the central Asian subspecies was extremely closely related to its Far Eastern cousin. In fact, although Caspian tigers were typically slightly smaller, their DNA differs from Amur tigers (sometimes known as Siberian tigers) by only a single letter of genetic code.

The tiger relocation plan aims to set up new tiger territory near the Ili River's delta, in Kazakhstan's southeast.

The world's wild tiger population is teetering on the brink of extinction, and, according to some estimates, only 3,200 big cats remain across 13 countries in eastern and southern Asia. Should Kazakhstan's plan prove successful, tigers would call 14 different countries home, up from the current 13.

At the world's first ever tiger summit, hosted by Russia in 2010, all 13 tiger range countries signed on to a long-range plan to save tigers and double their population by 2022, the next year of the tiger according to the Chinese zodiac.

Barney Long, head of Asian species conservation for WWF, applauded the Kazakh move to reintroduce tigers, and said the plan was good news for wild tigers in general.

"Efforts to grow the global tiger population will certainly benefit from expanding the tiger’s existing range," Long said.

Ancient Mite Caught Hitching Ride On Spider

Sticky amber caught a 50-million-year-old hitchhiker in action. This hitchhiker happened to be a tiny mite, catching a ride on the back of a spider.

In fact, it is the oldest mite found in amber and the oldest example of a mite hitching a ride on the back of a spider, researchers say.

X-ray view of astigmata mite on spider, trapped in amber.
X-ray view of astigmata mite on spider, trapped in amber.

Credit: A. McNeil

From the outside of the amber, the mite looks like a tiny bubble. It is so small, about 0.008 inches (.2 millimeters) long, normal microscopes and techniques aren't powerful enough to take a close look at the underside of the insect. The researchers used computers to create a 3-D image from a series of X-rays.

The images revealed this mite belonged to the group called astigmata, which includes more than 5,000 mite species in more than 70 families. The spider in the amber was of the family Dysderidae. [See images of insects in amber]

"This allowed us to actually say what type of mite it is. We can get a clear image of the animal involved," said study researcher Jason Dunlop, of Humboldt University in Berlin, Germany. "It looks exactly like a modern one."

Phorsing around

This mite-on-spider action caught in amber is the oldest example of "phorsey," in which one animal hitches a ride on another. Basically, when times are tough, some insects can add a juvenile stage to their life cycle, a stage in which they are equipped with special suckerlike appendages and can attach themselves to passing insects or other animals.

"We caught a mite on the process of being carried

The underside of the mite after recreation.
The underside of the mite after recreation.

Credit: A. McNeil

around," Dunlop said. "We can actually see this sucking pad attached to the back of the animal, and they use this to stick themselves onto other animals."

The passenger will hitch a ride until it outgrows this sucker stage and drops onto an area that, with luck, has more food. "If they are living in perfect conditions, they can skip this stage of the lifestyle. They only produce this stage with the sucker when things become poor, when it [the environment] starts drying out," Dunlop said.

Special spider

This type of mite doesn't usually hang around with spiders; they prefer beetles. The researchers say they don’t understand the behavior of modern mites that well, so they could well be hitching rides on today's spiders without us noticing.

"It's unusual to find them attached to a spider," Dunlop said. "But even the modern ones, we don't know all the aspects of their biology."

A modern mite similar to the astigmata hitchhiker.
A modern mite similar to the astigmata hitchhiker.

Credit: S. Wirth

This is one of the oldest mites on record. Researchers don't know much about the evolution of mites, since they are so small and don't fossilize well.

"This is the earliest example we have been able to document — it goes back 49 million years. It [this type of mite] is probably much older," Dunlop said. "We estimate this astigmata group might go back 270 million years and mites as a whole go back 410 million years."

The study was published Tuesday (Nov. 8) in the journal Biology Letters.

You can follow LiveScience staff writer Jennifer Welsh on Twitter @microbelover. Follow LiveScience for the latest in science news and discoveries on Twitter @livescience and on Facebook.'

60,000 Antelopes Died In 4 Days — And No One Knows Why

It started in late May.

When geoecologist Steffen Zuther and his colleagues arrived in central Kazakhstan to monitor the calving of one herd of saigas, a critically endangered, steppe-dwelling antelope, veterinarians in the area had already reported dead animals on the ground.

"But since there happened to be die-offs of limited extent during the last years, at first we were not really alarmed," Zuther, the international coordinator of the Altyn Dala Conservation Initiative, told Live Science.

But within four days, the entire herd — 60,000 saiga — had died. As veterinarians and conservationists tried to stem the die-off, they also got word of similar population crashes in other herds across Kazakhstan. By early June, the mass dying was over. [See Images of the Saiga Mass Die-Off]

Now, the researchers have found clues as to how more than half of the country's herd, counted at 257,000 as of 2014, died so rapidly. Bacteria clearly played a role in the saigas' demise. But exactly how these normally harmless microbes could take such a toll is still a mystery, Zuther said.

"The extent of this die-off, and the speed it had, by spreading throughout the whole calving herd and killing all the animals, this has not been observed for any other species," Zuther said. "It's really unheard of."

Crucial steppe players

Saigas play a critical role in the ecosystem of the arid grassland steppe, where the cold winters prevent fallen plant material from decomposing; the grazing of the dog-size, Gonzo-nosed antelopes helps to break down that organic matter, recycling nutrients in the ecosystem and preventing wildfires fueled by too much leaf litter on the ground. The animals also provide tasty meals for the predators of the steppe, Zuther said. [Images: Ancient Beasts of the Arctic]

"Where you find saiga, we recognize also that the other species are much more abundant," Zuther told Live Science.

Saigas, which are listed as critically endangered by the International Union for the Conservation of Nature, live in a few herds in Kazakhstan, one small herd in Russia and a herd in Mongolia. The herds congregate with other herds during the cold winters, as well as when they migrate to other parts of Kazakhstan, during the fall and spring. The herds split up to calve their young during the late spring and early summer. The die-off started during the calving period.

Die-offs of saigas, including one that felled 12,000 of the stately creatures last year, have occurred frequently in recent years. But the large expanse of the country affected by last year's die-off meant veterinarians couldn't get to the animals until long after their deaths. The delay hindered any determination of a cause of death, and researchers eventually speculated that an abundance of greenery caused digestion problems, which led to bacterial overgrowth in the animals' guts.

Detailed analysis

This time, field workers were already on the ground, so they were able to take detailed samples of the saigas' environment — the rocks the animals walked on and the soil they crossed — as well as the water the animals drank and the vegetation they ate in the months and weeks leading up to the die-off. The scientists also took samples of the ticks and other insects that feed on saiga, hoping to find some triggering cause.

The researchers additionally conducted high-quality necropsies of the animals, and even observed the behavior of some of the animals as they died. The females, which cluster together to calve their young, were hit the hardest. They died first, followed by their calves, which were still too young to eat any vegetation. That sequence suggested that whatever was killing off the animals was being transmitted through the mothers' milk, Zuther said.

Tissue samples revealed that toxins, produced by Pasteurella and possibly Clostridia bacteria, caused extensive bleeding in most of the animals' organs. But Pasteurella is found normally in the bodies of ruminants like the saigas, and it usually doesn't cause harm unless the animals have weakened immune systems.

Genetic analysis so far has only deepened the mystery, as the bacteria found were the garden-variety, disease-causing type.

"There is nothing so special about it. The question is why it developed so rapidly and spread to all the animals," Zuther said.

Mystery endures

A similar mass die-off of 400,000 saigas occurred in 1988, and veterinarians reported similar symptoms. But because that die-off occurred during Soviet times, researchers simply listed Pasteurellosis, the disease caused by Pasteurella, as the cause and performed no other investigation, Zuther added.

So far, the only possible environmental cause was that there was a cold, hard winter followed by a wet spring, with lots of lush vegetation and standing water on the ground that could enable bacteria to spread more easily, Zuther said. That by itself doesn't seem so unusual, though, he said.

Another possibility is that such flash crashes are inevitable responses to some natural variations in the environment, he said. Zuther said he and his colleagues plan to continue their search for a cause of the die-off.

Follow Tia Ghose on Twitterand Google+. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.