Skull analysis reveals insights into human ancestry
“Human fossils from after modern behavior became common have more feminine faces, and differences between the younger and older fossils are similar to those between faces of people with higher and lower testosterone levels living today,” said Robert Cieri, graduate biology student at the University of Utah and lead author of the paper, in a statement.
Heavy brows were out, rounder heads were in, and those changes can be traced directly to testosterone levels acting on the skeleton, according to Duke anthropologist Steven Churchill, who supervised Cieri while the student attended Duke.
Cieri compared the brow ridge, facial shape and interior volume of 13 modern human skulls older than 80,000 years, 41 skulls from 10,000 to 38,000 years ago, and a global sample of 1,367 20th century skulls from 30 different ethnic populations.
The trend that emerged was toward a reduction in the brow ridge and a shortening of the upper face, traits which generally reflect a reduction in the action of testosterone.
However, what the skulls do not reveal is whether the newly evolved humans produced and secreted less testosterone, or if they had fewer receptors for processing the hormone.
The feminization of facial structures and features due to lowered testosterone levels is in line with what has been established in non-human species. In a classic study of Siberian foxes, the animals that were less wary and less aggressive toward humans took on a different, more juvenile appearance and behavior after several generations of selective breeding.
“If we’re seeing a process that leads to these changes in other animals, it might help explain who we are and how we got to be this way,” said Brian Hare, animal cognition researcher at Duke University and co-author of the paper, in a statement. Scientists recently concluded that humans experienced a relatively sharp drop in testosterone about 50,000 years ago, which aided in the cultivation of modern human civilization, by looking at human skulls.
The study, titled, ‘Craniofacial feminization, social tolerance, and the origins of behavioral modernity’, was conducted by examining the shape and structure of skulls.
“Human fossils from after modern behavior became common have more feminine faces, and differences between the younger and older fossils are similar to those between faces of people with higher and lower testosterone levels living today,” said Robert Cieri, graduate biology student at the University of Utah and lead author of the paper, in a statement.
Heavy brows were out, rounder heads were in, and those changes can be traced directly to testosterone levels acting on the skeleton, according to Duke anthropologist Steven Churchill, who supervised Cieri while the student attended Duke.
Cieri compared the brow ridge, facial shape and interior volume of 13 modern human skulls older than 80,000 years, 41 skulls from 10,000 to 38,000 years ago, and a global sample of 1,367 20th century skulls from 30 different ethnic populations.
The trend that emerged was toward a reduction in the brow ridge and a shortening of the upper face, traits which generally reflect a reduction in the action of testosterone.
However, what the skulls do not reveal is whether the newly evolved humans produced and secreted less testosterone, or if they had fewer receptors for processing the hormone.
The feminization of facial structures and features due to lowered testosterone levels is in line with what has been established in non-human species. In a classic study of Siberian foxes, the animals that were less wary and less aggressive toward humans took on a different, more juvenile appearance and behavior after several generations of selective breeding.
“If we’re seeing a process that leads to these changes in other animals, it might help explain who we are and how we got to be this way,” said Brian Hare, animal cognition researcher at Duke University and co-author of the paper, in a statement.
Source: http://www.ascensionearth2012.org/2014/08/skull-analysis-reveals-insights-into.html
Anyone can join.
Anyone can contribute.
Anyone can become informed about their world.
"United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.
Before It’s News® is a community of individuals who report on what’s going on around them, from all around the world. Anyone can join. Anyone can contribute. Anyone can become informed about their world. "United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.
LION'S MANE PRODUCT
Try Our Lion’s Mane WHOLE MIND Nootropic Blend 60 Capsules
Mushrooms are having a moment. One fabulous fungus in particular, lion’s mane, may help improve memory, depression and anxiety symptoms. They are also an excellent source of nutrients that show promise as a therapy for dementia, and other neurodegenerative diseases. If you’re living with anxiety or depression, you may be curious about all the therapy options out there — including the natural ones.Our Lion’s Mane WHOLE MIND Nootropic Blend has been formulated to utilize the potency of Lion’s mane but also include the benefits of four other Highly Beneficial Mushrooms. Synergistically, they work together to Build your health through improving cognitive function and immunity regardless of your age. Our Nootropic not only improves your Cognitive Function and Activates your Immune System, but it benefits growth of Essential Gut Flora, further enhancing your Vitality.
Our Formula includes: Lion’s Mane Mushrooms which Increase Brain Power through nerve growth, lessen anxiety, reduce depression, and improve concentration. Its an excellent adaptogen, promotes sleep and improves immunity. Shiitake Mushrooms which Fight cancer cells and infectious disease, boost the immune system, promotes brain function, and serves as a source of B vitamins. Maitake Mushrooms which regulate blood sugar levels of diabetics, reduce hypertension and boosts the immune system. Reishi Mushrooms which Fight inflammation, liver disease, fatigue, tumor growth and cancer. They Improve skin disorders and soothes digestive problems, stomach ulcers and leaky gut syndrome. Chaga Mushrooms which have anti-aging effects, boost immune function, improve stamina and athletic performance, even act as a natural aphrodisiac, fighting diabetes and improving liver function. Try Our Lion’s Mane WHOLE MIND Nootropic Blend 60 Capsules Today. Be 100% Satisfied or Receive a Full Money Back Guarantee. Order Yours Today by Following This Link.
| Visits: | 1,708,647,295 |
| Stories: | 8,450,881 |
Whistler Blowers, Insiders
