We’ve been taught for decades that the microbes inside us outnumber our own cells. And we’ve often been told it’s by a ratio of 10:1. That number was first introduced in 1972 as more of a vague estimate, without much significant factual basis, and has been perpetuated ever since. Now, however, scientists have offered up a new estimate.
Image Credit: MJ Richardson via geograph.org.uk
The next time you fight off the flu, you might want to thank your ancestors for flirting with the Neanderthal down the way. According to a pair of new studies, interbreeding between several early human species may have given us a key ingredient in fighting disease.
While scientists once scoffed at the idea that our ancestors may have mated with their “cousins,” over the last six years a growing body of evidence drawn from several large genetic sequencing projects says otherwise. Not only did our ancient ancestors interbreed with Neanderthals, but recent finds indicate they likely mated with a third ancient human species called the Denisovans as well.
And this wasn’t just a one-time thing. Studies indicate that our ancestors got it on with these other ancient humans often enough that us modern humans have inherited about 1 to 2 percent of our DNA from them, Sarah Kaplan reports for the Washington Post.
Now, scientists working on two independent studies have come to similar conclusions. Some of this DNA left over from liasons with Neanderthals and Denisovans play a big role in strengthening our immune systems to fight off infection and disease.
HAPPY HOLIDAYS EVERYONE!!!
Margaret Mead (via humanisticscience)
Cutaway mandible showing developing dentition
Can’t hold your drink? This could be why.
Everybody has a different level of tolerance for alcohol, but for some people, even having a small amount to drink can make them act very strangely, exhibiting reckless, impulsive, or sometimes even dangerous behaviour.
Now a new study sheds light on one of the underlying biological causes for this, with a team of Finnish researchers finding that a mutation in some people’s serotonin 2B receptor gene can render them prone to impulsive behaviour, especially when they’re under the influence of alcohol.
“Hobbits! Dragons! Weird elephants and ancient mysteries! It’s the stuff of literary and box office gold. And it turns out it’s the stuff of prehistory, too! In 2004 a group of paleontologists working on the island of Flores, a part of the Indonesian archipelago, discovered the bones of small people in a cave called Liang Bua. The bones represented several individuals that were only 3’ 6” tall (A little more than a meter for the metrically inclined). Our guest this week, Dr. William Jungers from Stony Brook University and past guest Dr. Susan Larson, were invited to join the team to work on the skeleton of Homo floresiensis or “The Hobbit.” The skull ofHomo floresiensis was weird, with a tiny brain and primitive features that connected the species to a more ancient species of hominin (bipedal apes) thanHomo sapiens. Initial work on the fossils suggested the hobbits were small versions of Homo erectus one of the first bipedal apes to make it to Asia with large brains and tall statures. But the evidence has begun to pile up connecting Homo floresiensis to a smaller, less-brainy species called Homo habilis, a species that was never thought to have made it out of Africa. Get caught up on the state of hobbit science in this episode of Past Time and be prepared for even more fascinating discoveries to come out of Flores!
The best way to listen in, is to subscribe to Past Time through iTunes. Or if you prefer, you can download the episode or stream it directly through your browser here. Don’t forget you can follow us on Twitter, where the newest member of our team, Thomas Salerno, has been reporting on the latest in paleontological and archaeological news or like us on Facebook where we will keep you updated on new episodes and the world of the past” (read more).
(Source: Past Time)
By the way, a cautionary tale
If you find a bunch of bones that are A: untouched and B: supernaturally clean, there is definitely a reason for both of those things. Sometimes that reason is ants. Sometimes those ants are fire ants. Sometimes those fire ants have made a nest over the entire three meter area around those bones
i like this story
eSkeletons is run by the University of Texas at Austin, and they’ve been good enough to upload images of various bones (in several views), of several species of primates, both human and non-human. They also have taxonomic trees, and a comparative anatomy section where you can specify which taxa, which bones, and which views you’re interested in.
I found this website on a list of recommended resources for my anatomy course, and it’s been rather helpful, so I thought I’d share.
And this is what happens when you let anthropology students have fairy lights.
A DNA analysis of four ancient Roman skeletons found in London shows the first inhabitants of the city were a multi-ethnic mix similar to contemporary Londoners, the Museum of London said on Monday.
Two of the skeletons were of people born outside Britain—one of a man linked genealogically to eastern Europe and the Near East, the other of a teenage girl with blue eyes from north Africa.
The injuries to the man’s skull suggest that he may have been killed in the city’s amphitheatre before his head was dumped into an open pit. Both the man and the girl were suffering from periodontal disease, a type of gum disease.
The other two skeletons of people believed to have been born in Britain were of a woman with maternal ancestry from northern Europe and of a man also with links through his mother to Europe or north Africa. Read more.
“If you’re an osteology or anatomy student seeking tips and tricks, an instructor looking for engaging identification and siding tutorials, or are simply interested in learning more about human bones, look no further! On this page I’ve compiled links to all of my identification and siding posts, many of which come with printable pdfs. The posts are organized by anatomical region, below.
Teeth
Skull
Spine and Rib Cage
Arm, Wrist and Hand
Leg, Ankle and Foot
Points of Palpable Anatomy
If there are specific future posts you’d be interested in seeing, jot them down in the comments. Similarly, if you’ve used any of my blog posts when teaching, please let me know as I’m trying to gauge how useful these posts are for instructors!”
(Source: Bone Broke; image: Santiago Caruso: Wunderkammer)
Every one of my trillion or so ancestors, from my human parents to the first single cell organism that ever existed, survived long enough to reproduce.
41 years ago today, the modern world met Lucy (Australopithecus afarensis)
HAPPY DISCOVERY DAY, YOU GORGEOUS GIRL
An estimated 30 trillion cells in your body—less than a third—are human. The other 70-90% are bacterial and fungal!
Learn more in the new exhibition, The Secret World Inside You, now open!
Image: Gaby D'Allesandro / © AMNH
college professor: i’m rejecting your evolutionary biology thesis me: wtf why dude college professor: you added “(lmao)” every time you mentioned the species Homo Erectus
