For centuries, the purpose of a narwhal’s tusk has eluded explanation. Now, researchers suggest that these small whales use their tusks as sensory organs and speculate that sensing changes in seawater salinity might help male narwhals stay safe, and locate fish or females.
Narwhals are a little bit like Arctic unicorns. At least, the males are. They’re the beasts that swim around wielding giant, spiraling tusks that can grow to nearly 9 feet long. But unlike the mythical horned horse, narwhals are a) real and b) their horns aren’t centered on their faces. Instead, their tusks protrude from the left of their mouths – they’re actually big, twisted canine teeth (the right canine usually remains embedded in the whale’s jaw).
Since at least the 15th century, scientists have been mulling over the purpose of the narwhal’s super-long tooth, proposing roles in defense, attracting a mate, hunting, hearing, breathing, and ice-breaking, among others. Now, it seems clear that the tooth is capable of acting like an enormous sensory organ, says Harvard University’s Martin Nweeia, a marine mammal dental specialist. Nweeia and his colleagues have been studying narwhals in the Arctic for more than a decade, and published a paper describing the tooth’s sensory capabilities today in The Anatomical Record.
“It takes a tremendous amount of energy and devotion to get that thing to grow,” Nweeia says. “To expend that much energy in such a harsh environment – there has to be a pretty compelling reason to do it.”
Nweeia and his colleagues collected narwhal tusks from Inuit hunters near Baffin Island, then studied those tusks for anatomical clues to their function. Turns out, narwhal tusks are filled with a nerve-rich pulp that’s similar to the stuff in human teeth that can sometimes make drinking coffee or eating ice cream a painful experience.
Next, the team looked to see if there were any genes expressed by the pulp that would indicate a role in relaying sensory information to the brain. And there were: two genes expressed in sensory signaling pathways were present at much higher levels in tusk pulp than in muscle or jaw tissues.
Nweeia then decided to test whether the tusks helped convey information about salt concentration in the surrounding sea. To do this, he fitted narwhals with a “tusk jacket” – a clear plastic tube that encloses the tusk, from one end to the other. He attached electrodes to the animals so that he could measure their heart rate. Then he bathed the jacketed tusks in solutions with either high or low concentrations of dissolved salt – a situation that mimics changes to seawater as icebergs form (high salt) or melt (low salt).
He found that narwhal heart rates rose in response to high salt concentrations, presumably because these concentrations normally suggest that the sea is freezing and entrapment is possible. The animals’ heart rates dropped when the tusks were washed with fresh water, suggesting they could detect this change. But, Nweeia says, salt is just one of many environmental stimuli the tusks could be sensing. “Our premise was just to open the pathway for people understand that this is a sensory organ,” he says. “Now the pathway is open for people, including ourselves, to look at other variables it might also detect.”
By Owen Jarus, Live Science Contributor | September 17, 2014
More than 3,300 years ago, in a newly built city in Egypt, a woman with an incredibly elaborate hairstyle of lengthy hair extensions was laid to rest.
She was not mummified, her body simply being wrapped in a mat. When archaeologists uncovered her remains they found she wore “a very complex coiffure with approximately 70 extensions fastened in different layers and heights on the head,” writes Jolanda Bos, an archaeologist working on the Amarna Project, in an article recently published in the Journal of Egyptian Archaeology.
Researchers don’t know her name, age or occupation, but she is one of hundreds of people, including many others whose hairstyles are still intact, who were buried in a cemetery near an ancient city now called Amarna.
This city was constructed as a new capital of Egypt by Akhenaten (reign ca. 1353-1335 B.C.), a pharaoh who unleashed a religious revolution that saw the Aten, a deity shaped as a sun disk, assume supremacy in Egyptian religion. Akhenaten ordered that Amarna be constructed in the desert and that images of some of Egypt’s other gods be destroyed. Amarna was abandoned shortly after Akhenaten’s death, and today archaeologists supported by the Amarna Trust are investigating all aspects of the ancient city, including the hairstyles its people wore.
Bos is leading the hairstyle research, and the woman with 70 extensions leaves her puzzled.
"Whether or not the woman had her hair styled like this for her burial only is one of our main research questions," said Bos in an email to Live Science. "The hair was most likely styled after death, before a person was buried. It is also likely, however, that these hairstyles were used in everyday life as well and that the people in Amarna used hair extensions in their daily life."
Many of the other skulls Bos analyzed also had hair extensions. One skull had extensions made of gray and dark black hair suggesting multiple people donated their hair to create extensions.
As Bos analyzed a selection of 100 recently excavated skulls (of which 28 still had hair) from the Armana cemetery, she noticed the people who lived in the ancient city had a wide variety of hair types. They range “from very curly black hair, to middle brown straight,” she noted in the journal article, something “that might reflect a degree of ethnic variation.”
Those skulls with brown hair often had rings or coils around their ears, a style that was popular at Amarna, she found. Why people in this city liked it is unknown. “We still have no idea. This is of course one of the answers we are still trying to find from the record,” said Bos in the email.
People in the city also seemed to be fond of braids. “All braids found in the coiffures were simple and of three strands, mostly 1 cm [0.4 inches] wide, with strands of approximately 0.5 cm [0.2 inches] when tightly braided,” Bos writes in the journal article.
People at Amarna also liked to keep their hair short. “Braids were often not more than 20 cm [7.9 inches] long, leaving the hair at shoulder length approximately,” Bos added. “The longest hair that was found consisted of multilayered extensions to a length of approximately 30 cm [11.8 inches].”
Fat was used to help create all the hairstyles Bos found, something that would have helped keep the hair in one piece after death. More research is needed to determine whether the fat was from animals. A textile found on each of the skulls may have been used to cover part of the head.
Hide the gray?
In one case a woman has an orange-red color on her graying hair. It appears that that she dyed her hair, possibly with henna (a flowering plant).
"We are still not completely sure if and what kind of hair coloring was used on this hair, it only seems that way macroscopically," said Bos in the email. "At present we are analyzing the hairs in order to find out whether or not some kind of coloring was used. On other sites dyed hair was found from ancient Egypt."
This woman, among other ancient Egyptians, may have dyed her hair “for the same reason as why people dye their hair today, in order not to show the gray color,” Bos said.
Sword wound that removed the left maxilla and the right mandible so that no remaining teeth were in occlusion. Healing and long term survival are evident from the bone remodeling that has occurred. (a) Anterior view. (b) Left oblique view, showing details of the trauma and subsequent healing. (Adult male from an archeological site near the Stewart River, Queensland, Australia, SAM A 11411.)
In: Ortner, D.J. (1985) Identification of Pathological Conditions in Human Skeletal Remains. Academic Press Inc: Massachusetts, p. 143.
Apollo in his chariot with the hours: John Singer Sargent
A dress designed to change color in the rain, thanks to dye sewn into
the seams. Created by Sean Kelly, Modeled by Angelica Guillen-Jimenez
this was so iconic, i’m glad i was alive for it
Hazelnut Cake w/Fig Compote | Dolly & Oatmeal
How many altos does it take to screw in a lightbulb?
None, they can’t get that high.
How many sopranos does it take to screw in a lightbulb?
One, she holds it up and waits for the world to revolve around her.
How many singers does it take to screw in a lightbulb?
Two. An alto to actually do it and a soprano to stand by and ask “isn’t that a little high for you?”
T4 Bacteriophage” is a virus like the robot in the living body.
Artificial nano “T4 Bacteriophage” was fabricated by FIB-CVD on Si surface.
Size of the artificial nano “T4 Bacteriophage” is about ten times as large as the real virus
by Reo Kometani & Shinji Matsui (University of Hyogo)
Get into the spirit with a slashed-up skull sweatshirt.
"Son," the father says, examining the broken petri dishes littered about the floor, “I’m not a mad scientist, I’m just a disappointed scientist.”
I don’t even care what you think this is the best post I’ve ever made
ICELAND, Vatnajoekull : An aerial picture taken on September 14, 2014 shows lava flowing out of the Bardarbunga volcano in southeast Iceland. The Bardarbunga volcano system has been rocked by hundreds of tremors daily since mid-August, prompting fears the volcano could explode. Bardarbunga, at 2,000 metres (6,500 feet), is Iceland’s second-highest peak and is located under Europe’s largest glacier, Vatnajoekull. AFP PHOTO / BERNARD MERIC
our biology teacher brought a skeleton to class yesterday and now everyone’s treating it as if it’s a part if our class i’m going to
Yes, the world is a vulnerable place and yes, we help make it that way. But we’re also the ones best qualified to defend it.
#this is a buildup to civil war this has to be a buildup to civil war#marvel keeps coming back to this- has to keep coming back to this#and can’t ever find a satisfying solution#there’s the tony/natasha ‘you won’t arrest us bc we’re doing a better job than the world’s police’#which isn’t morally sustainable!#it’s an argument for privatized vigilantism!#you have the steve rogers solution which is: work for the gov’t#but that doesn’t even work for steve himself- the gov’t isn’t any more trustworthy than your own enemy#and the third piece of the puzzle is thor#and the marvelverse responds to thor with:#we have to build weapons to fight him#how is the mcu supposed to deal with the problem of superheroes?#libertarian privatization? totalitarian absorption into a corrupt government institution? or destruction?#it has to be addressed and it has to be explored and IT HAS TO BE CIVIL WAR and it’s going to be incredible (swanjolras)