Sunday, December 2, 2012
luna0abbi:

Australopithecus afarensis, one of the first bipedal apes that climbed down from the trees and left a life in the forest to walk on the grounds of Africa is nicknamed Lucy. When her fossils were discovered in Ethiopia in 1974, Donald Johanson and his team celebrated by listening to Lucy In The Sky With Diamonds by The Beatles on repeat, and so giving her the name of Lucy. 

luna0abbi:

Australopithecus afarensis, one of the first bipedal apes that climbed down from the trees and left a life in the forest to walk on the grounds of Africa is nicknamed Lucy. When her fossils were discovered in Ethiopia in 1974, Donald Johanson and his team celebrated by listening to Lucy In The Sky With Diamonds by The Beatles on repeat, and so giving her the name of Lucy. 

rhamphotheca:

“Lucy’s Baby” a Born Climber, Hinting Human Ancestors Lingered in Trees

Australopithecus afarensis’ shoulders pointed upward, new fossil study suggests.

by James Owen

What made us human? Part of the answer may rest on the shoulders of a 3.3-million-year-old toddler.

Like “Lucy,” the fossil child was a member of the speciesAustralopithecus afarensis, pioneers of upright walking. Yet her apelike shoulder blades hint that our forebears may have taken longer than we thought to fully come down to earth, a new study says.

Figuring out when the tree-to-ground transition took place is immensely important to understanding how we became who we are. Bipedalism, after all, gave prehumans a literal head’s-up on approaching predators and freed up hands for stone tools, which in turn gave access to more types of food, including brain-boosting animal proteins—among other advantages.

The tiny fossils—including the only known complete A. afarensis scapula, or shoulder blade—add to evidence that that giant stride was more a series of faltering steps.

“What we’re showing is that bipedalism wasn’t this sudden change that took shape in an early common ancestor,” said study co-author David Green, an anatomy professor at Midwestern University in Downers Grove, Illinois. “As bipedalism was developing, there were other forms of locomotion that were still important.”

(read more: National Geo)

(images: T - Dave Einsel/Getty; B - Zeray Alemseged / Dikika Research Project)

lascauxxx:

Cro-Magnon 2, a female skull from the site of Les Eyzies, Dordogne, France. Another skull from this site (Cro-Magnon 1) was carbon dated to about 28,000 14C years old. (27,680 ± 270 BP).
The condition and placement of the remains of Cro-Magnon 1, along with pieces of shell and animal teeth in what appear to have been pendants or necklaces, raises the question of whether they were buried intentionally. If Cro-Magnons buried their dead intentionally, it suggests they had a knowledge of ritual, by burying their dead with necklaces and tools, or an idea of disease and that the bodies needed to be contained.
Analysis of the pathology of the skeletons shows that the humans of this period led a physically difficult life. In addition to infection, several of the individuals found at the shelter had fused vertebrae in their necks, indicating traumatic injury; the adult female found at the shelter had survived for some time with a skull fracture. As these injuries would be life threatening even today, this suggests that Cro-Magnons believed in community support and took care of each other’s injuries.
(From Wikipedia)

lascauxxx:

Cro-Magnon 2, a female skull from the site of Les Eyzies, Dordogne, France. Another skull from this site (Cro-Magnon 1) was carbon dated to about 28,000 14C years old. (27,680 ± 270 BP).

The condition and placement of the remains of Cro-Magnon 1, along with pieces of shell and animal teeth in what appear to have been pendants or necklaces, raises the question of whether they were buried intentionally. If Cro-Magnons buried their dead intentionally, it suggests they had a knowledge of ritual, by burying their dead with necklaces and tools, or an idea of disease and that the bodies needed to be contained.

Analysis of the pathology of the skeletons shows that the humans of this period led a physically difficult life. In addition to infection, several of the individuals found at the shelter had fused vertebrae in their necks, indicating traumatic injury; the adult female found at the shelter had survived for some time with a skull fracture. As these injuries would be life threatening even today, this suggests that Cro-Magnons believed in community support and took care of each other’s injuries.

(From Wikipedia)

alphacaeli:

The Taung Child (Australopithecus africanus).
This is a rather lovely photograph of a poignant fossil. 

alphacaeli:

The Taung Child (Australopithecus africanus).

This is a rather lovely photograph of a poignant fossil. 

Saturday, December 1, 2012

skeptv:

New Brain Model of Earliest Primate

Researchers from the universities of Florida and Winnipeg have reconstructed the brain of Ignacius graybullianus, one of the earliest primates known, from a 54-million-year-old fossil skull. It’s the most complete brain model of its kind and casts new light on the beginnings of primate brain development.

skeptv:

Chimps Show Complex Body Language

Apes use complex combinations of gestures and facial and vocal signals to communicate. A new study by scientists at the Yerkes National Primate Research Center at Emory University adds to a growing body of evidence that gesture, not vocal signals, evolved into human speech. Watch chimpanzees gesture and learn what brain regions may control this behavior in this Human Bulletin.

Thursday, November 29, 2012
deconversionmovement:

Primate Origins Tied to Rise of Flowering Plants
One of the great origin stories in the history of mammals is the rise of primates. It’s a story that scientists are still trying to write.
In the early 20th century, anatomists believed primates—united by big brains, grasping hands and feet, and excellent vision, among other features—evolved in response to living in trees. In the 1970s, however, biological anthropologist Matt Cartmill realized an arboreal lifestyle alone wasn’t enough to explain primates’ unique set of characteristics. Plenty of mammals, like chipmunks, live in trees but don’t have nimble hands or closely spaced, forward-facing eyes that allow for good depth perception. Instead, Cartmill suggested these features evolved because early primates were insect predators. He noted that many modern predators, such as cats and owls, have forward-facing eyes because they rely on good vision to grab prey. In the case of early primates, Cartmill said, they hunted tree-dwelling insects.
Not long after Cartmill presented his explanation of primates’ roots, other researchers came up with an alternative idea: Primates evolved in step with the spread of flowering plants. Rather than relying on good vision and dexterity to nab bugs, early primates used these traits to carefully walk out to the ends of delicate tree branches to gather fruits and flowers, as well as the insects that pollinated flowering plants.
Physical anthropologists Robert Sussman and D. Tab Rasmussen of Washington University and botanist Peter Raven of the Missouri Botanical Garden review the latest evidence in support of this hypothesis in an article published online in the American Journal of Primatology.
The team suggests that the earliest primates and their extinct close relatives, a group called plesiadapiforms, weren’t strictly insect eaters and therefore the insect predation hypothesis doesn’t hold up. They point out that the molars of plesiadapiforms are rounder than the teeth of earlier mammals, which were sharp for puncturing bugs. The flatter teeth indicate plesiadapiforms were probably grinding fruits, nuts and other plant parts.
The switch to a plant diet coincides with the rise of rise of flowering plants. The earliest flowering plants show up in the fossil record roughly 130 million years ago and became the dominant type of forest plant by about 90 million years ago. Around 56 million years ago, global temperatures spiked and tropical forests spread around the world. About this time, many species of birds and bats emerged. Primates also diversified during this period. Sussman and his colleagues argue that while birds and bats could fly to the ends of branches to consume meals of fruit and nectar, primates took a different route, evolving adaptations that enabled them to be better climbers.
The skeleton of a 56-million-year-old plesiadapiform found in Wyoming provides further evidence of this scenario, the researchers say. Much of the early primate and plesiadapiform fossil record consists of teeth, but in 2002, scientists reported the discovery of the skull, hands and feet of Carpolestes simpsoni. The bones reveal that the species was a good grasper, with an opposable big toe and nails instead of claws. And the teeth indicate the creature ate fruit. But unlike living primates, C. simpsoni did not have forward-facing eyes, suggesting it didn’t have good depth perception. This is an important finding, Sussman and colleagues say. If primates evolved their characteristic features because they were visual predators, then you’d expect good vision to evolve in concert with good grasping. Instead, the C. simpsoni fossils suggest enhanced vision came later. Forward-facing eyes may have later evolved because it helped primates see through the cluttered, leafy environment of the forest canopy.
The team’s arguments rest heavily on evidence from plesiadapiforms. In the past, anthropologists have debated plesiadapiforms close connection to primates. However, Sussman and colleagues think the fossil evidence suggests the two groups shared a common ancestor, and thus the evolutionary trends seen in plesiadapiforms serve as a good guide for what happened in primates.
Continue Reading

deconversionmovement:

Primate Origins Tied to Rise of Flowering Plants

One of the great origin stories in the history of mammals is the rise of primates. It’s a story that scientists are still trying to write.

In the early 20th century, anatomists believed primates—united by big brains, grasping hands and feet, and excellent vision, among other features—evolved in response to living in trees. In the 1970s, however, biological anthropologist Matt Cartmill realized an arboreal lifestyle alone wasn’t enough to explain primates’ unique set of characteristics. Plenty of mammals, like chipmunks, live in trees but don’t have nimble hands or closely spaced, forward-facing eyes that allow for good depth perception. Instead, Cartmill suggested these features evolved because early primates were insect predators. He noted that many modern predators, such as cats and owls, have forward-facing eyes because they rely on good vision to grab prey. In the case of early primates, Cartmill said, they hunted tree-dwelling insects.

Not long after Cartmill presented his explanation of primates’ roots, other researchers came up with an alternative idea: Primates evolved in step with the spread of flowering plants. Rather than relying on good vision and dexterity to nab bugs, early primates used these traits to carefully walk out to the ends of delicate tree branches to gather fruits and flowers, as well as the insects that pollinated flowering plants.

Physical anthropologists Robert Sussman and D. Tab Rasmussen of Washington University and botanist Peter Raven of the Missouri Botanical Garden review the latest evidence in support of this hypothesis in an article published online in the American Journal of Primatology.

The team suggests that the earliest primates and their extinct close relatives, a group called plesiadapiforms, weren’t strictly insect eaters and therefore the insect predation hypothesis doesn’t hold up. They point out that the molars of plesiadapiforms are rounder than the teeth of earlier mammals, which were sharp for puncturing bugs. The flatter teeth indicate plesiadapiforms were probably grinding fruits, nuts and other plant parts.

The switch to a plant diet coincides with the rise of rise of flowering plants. The earliest flowering plants show up in the fossil record roughly 130 million years ago and became the dominant type of forest plant by about 90 million years ago. Around 56 million years ago, global temperatures spiked and tropical forests spread around the world. About this time, many species of birds and bats emerged. Primates also diversified during this period. Sussman and his colleagues argue that while birds and bats could fly to the ends of branches to consume meals of fruit and nectar, primates took a different route, evolving adaptations that enabled them to be better climbers.

The skeleton of a 56-million-year-old plesiadapiform found in Wyoming provides further evidence of this scenario, the researchers say. Much of the early primate and plesiadapiform fossil record consists of teeth, but in 2002, scientists reported the discovery of the skull, hands and feet of Carpolestes simpsoni. The bones reveal that the species was a good grasper, with an opposable big toe and nails instead of claws. And the teeth indicate the creature ate fruit. But unlike living primates, C. simpsoni did not have forward-facing eyes, suggesting it didn’t have good depth perception. This is an important finding, Sussman and colleagues say. If primates evolved their characteristic features because they were visual predators, then you’d expect good vision to evolve in concert with good grasping. Instead, the C. simpsoni fossils suggest enhanced vision came later. Forward-facing eyes may have later evolved because it helped primates see through the cluttered, leafy environment of the forest canopy.

The team’s arguments rest heavily on evidence from plesiadapiforms. In the past, anthropologists have debated plesiadapiforms close connection to primates. However, Sussman and colleagues think the fossil evidence suggests the two groups shared a common ancestor, and thus the evolutionary trends seen in plesiadapiforms serve as a good guide for what happened in primates.

Continue Reading

ascelbio:

Antibiotics Are a Gift to Be Handled With Care!
“New studies challenge us to think about the effects of antibiotics on the bacterial populations that accompany us through life, and to treat the great gift of antibiotics with deeper understanding and respect.”—-NYTimes
NOVEMBER 12, 2012, 4:39 PM
By PERRI KLASS, M.D
Read on at:
http://well.blogs.nytimes.com/2012/11/12/antibiotics-are-a-gift-to-be-handled-with-care/

ascelbio:

Antibiotics Are a Gift to Be Handled With Care!

“New studies challenge us to think about the effects of antibiotics on the bacterial populations that accompany us through life, and to treat the great gift of antibiotics with deeper understanding and respect.”—-NYTimes

NOVEMBER 12, 2012, 4:39 PM

By PERRI KLASS, M.D

Read on at:

http://well.blogs.nytimes.com/2012/11/12/antibiotics-are-a-gift-to-be-handled-with-care/

Friday, November 9, 2012

elegantbuffalo:

The coelacanth is a rare species of fish, thought to be extinct as it had disappeared from the fossil record for 80 million years until a live specimen was discovered in 1938 off the coast of South Africa.

One of the most interesting morphological characteristics of the coelacanth is its independently moving fins, which are precursors to limbs.

However, a fossil find back in 2007 revealed that “the asymmetry in our own paired limbs is in fact a primitive feature,” says Michael Coates of the University of Chicago.

Thursday, November 8, 2012 Tuesday, September 25, 2012 Sunday, May 6, 2012

Presented for your enjoyment without comment.

(Source: evolvingcomplexityii.wordpress.com)

Monday, April 30, 2012 Sunday, April 22, 2012

bridgewithatee:

From So Simple a Beginning

Artist Pery Burge uses ink and water to illustrate the essence of Darwin’s words, “…from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved.”