Contact Information:

Media Contact

Lisa Marie Potter
lisa.potter@ucsf.edu
415-502-6397

Twitter: ucsf

http://www.ucsf.edu




Kredyty mieszkaniowe Kredyty mieszkaniowe

Sprawdź aktualny ranking najlepszych kredytów mieszkaniowych w Polsce - atrakcyjne kredytowanie nieruchomości.

PRESS-NEWS.org - Press Release Distribution
FREE PRESS RELEASES DISTRIBUTION
RSS - Press News Release
Add Press Release

Shouldering the burden of evolution

UCSF study shows how early tool use shaped our body


2015-09-08
(Press-News.org) As early humans increasingly left forests and utilized tools, they took an evolutionary step away from apes. But what this last common ancestor with apes looked like has remained unclear. A new study led by researchers at UC San Francisco shows that important clues lie in the shoulder.

Humans split from our closest African ape relatives in the genus Pan - including chimpanzees and bonobos - 6 to 7 million years ago. Yet certain human traits resemble the more distantly related orangutan or even monkeys. This combination of characteristics calls into question whether the last common ancestor of modern humans and African apes looked more like modern day chimps and gorillas or an ancient ape unlike any living group.

"Humans are unique in many ways. We have features that clearly link us with African apes, but we also have features that appear more primitive, leading to uncertainty about what our common ancestor looked like," said Nathan Young, PhD, assistant professor at UC San Francisco School of Medicine and lead author of the study. "Our study suggests that the simplest explanation, that the ancestor looked a lot like a chimp or gorilla, is the right one, at least in the shoulder."

It appears, he said, that shoulder shape tracks changes in early human behavior such as reduced climbing and increased tool use. The paper, titled Fossil Hominin Shoulders Support an African Ape-like Last Common Ancestor of Chimpanzees and Humans, published online Sept. 6, in the journal PNAS.

The shoulders of African apes consist of a trowel-shaped blade and a handle-like spine that points the joint with the arm up toward the skull, giving an advantage to the arms when climbing or swinging through the branches. In contrast, the scapular spine of monkeys is pointed more downwards. In humans this trait is even more pronounced, indicating behaviors such as stone tool making and high-speed throwing. The prevailing question was whether humans evolved this configuration from a more primitive ape, or from a modern African ape-like creature, but later reverted back to the downward angle.

The researchers tested these competing theories by comparing 3-D measurements of fossil shoulder blades of early hominins and modern humans against African apes, orangutan, gibbons and large, tree-dwelling monkeys. They found that the modern human's shoulder shape is unique in that it shares the lateral orientation with orangutans and the scapular blade shape with African apes; a primate in the middle.

"Human shoulder blades are odd, separated from all the apes. Primitive in some ways, derived in other ways, and different from all of them," Young said. "How did the human lineage evolve and where did the common ancestor to modern humans evolve a shoulder like ours?"

To find out, Young and his team analyzed two early human Australopithecus species, the primitive A. afarensis and younger A. sediba, as well as H. ergaster and Neandertals, to see where they fit on the shoulder spectrum.

"Finding fossil remains of the common ancestor would be ideal, however, when fossils are absent, employing such multifaceted techniques is the next best solution," said Zeray Alemseged, PhD, senior curator of Anthropology at the California Academy of Sciences.

The results showed that australopiths were intermediate between African apes and humans: the A. afarensis shoulder was more like an African ape than a human, and A. sediba closer to human's than to an ape's. This positioning is consistent with evidence for increasingly sophisticated tool use in Australopithecus.

"The mix of ape and human features observed in A. afarensis' shoulder support the notion that, while bipedal, the species engaged in tree climbing and wielded stone tools. This is a primate clearly on its way to becoming human," Alemseged said.

These shifts in the shoulder also enabled the evolution of another critical behavior - human's ability to throw objects with speed and accuracy, said Neil T. Roach, PhD, a fellow of human evolutionary biology at Harvard University. A laterally facing shoulder blade allows humans to store energy in their shoulders, much like a slingshot, facilitating high-speed throwing, an important and uniquely human behavior.

"These changes in the shoulder, which were probably initially driven by the use of tools well back into human evolution, also made us great throwers," Roach said. "Our unique throwing ability likely helped our ancestors hunt and protect themselves, turning our species into the most dominant predators on earth."

However, this remarkable ability has trade offs -- partly because of that downward scapular tilt, humans can throw fastballs, but are also prone to shoulder injuries. Today, Americans get approximately 2 million rotator cuff injuries each year, but not everyone is at equal risk. Because shoulder shape varies widely among modern humans, understanding these variations could help predict which people are more prone to injury.

"We could potentially use information about the shape of an individual's shoulder to predict if they have a higher likelihood of injury and then recommend personalized exercise programs that would best help to prevent them," Young said. "For a baseball pitcher, depending on your shoulder shape, you might want to emphasize some strengthening exercises over others to protect your rotator cuff."

The researchers' next step will be to analyze variability in the shoulder blade of modern humans and the genetic sequences that cause those differences to understand how these factors influence the likelihood to get rotator cuff injuries.

"Once we understand how the shape of the shoulder blade affects who gets injured, the next step is to find out what genes contribute to those injury prone shapes," said Terence Capellini, PhD, assistant professor of human evolutionary biology at Harvard University. "With that information, we hope that one day doctors can diagnose and help prevent shoulder injuries years before they happen, simply by rubbing a cotton swab on a patient's cheek to collect their DNA".

INFORMATION:

This work was supported by funding from the National Science Foundation (Grant BCS-1518596); Margaret and William Hearst; the National Institutes of Health (Grants R01DE019638 and R01DE021708); and the ongoing support of the UCSF Orthopaedic Trauma Institute and the Laboratory for Skeletal Regeneration at San Francisco General Hospital.

UC San Francisco (UCSF) is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care. It includes top-ranked graduate schools of dentistry, medicine, nursing and pharmacy, a graduate division with nationally renowned programs in basic, biomedical, translational and population sciences, as well as a preeminent biomedical research enterprise and two top-ranked hospitals, UCSF Medical Center and UCSF Benioff Children's Hospital San Francisco.


ELSE PRESS RELEASES FROM THIS DATE:

Ozone can reduce a flower's scent that's critical for attracting pollinators

2015-09-08
New research shows that high levels of ozone, which are predicted to increase in the atmosphere in the future, can dampen the scents of flowers that attract bees and other pollinators. High ozone concentrations in ambient air caused fast degradation of the scent emitted from Brassica nigra flowers, reducing the range over which flowers could be identified by pollinators. Behavioral tests conducted with the buff-tailed bumblebee confirmed that ozone concentrations commonly occurring near large urban areas can strongly inhibit pollinators' attraction to flowers. ?"The ...

Drugs behave as predicted in computer model of key protein, enabling cancer drug discovery

Drugs behave as predicted in computer model of key protein, enabling cancer drug discovery
2015-09-08
Drugs important in the battle against cancer responded the way they do in real life and behaved according to predictions when tested in a computer-generated model of one of the cell's key molecular pumps -- the protein P-glycoprotein, or P-gp. Biologists at Southern Methodist University, Dallas, developed the computer generated model to overcome the problem of relying on only static images for the structure of P-gp, said biologist John G. Wise, lead author on the journal article announcing the advancement. The new SMU model allows researchers to dock nearly any drug ...

As demand for African timber soars, birds pay the ultimate price

As demand for African timber soars, birds pay the ultimate price
2015-09-08
Tropical forests are home to more of the world's terrestrial biodiversity than any other habitat, but are increasingly threatened by the impact of human activities. Illegal logging, in particular, poses a severe and increasing threat to tropical forests worldwide. But, until now, its impact on tropical wildlife has not been quantified. A new study co-authored by scientists at Drexel University, published in the most recent issue of Biological Conservation, reveals the devastating impact of illegal logging on bird communities in the understory layer of Ghana's Upper Guinea ...

Arthritis may be a major driver of poverty

2015-09-08
Developing arthritis increases the risk of falling into poverty, especially for women, new research shows. In a study of more than 4,000 Australian adults, females who developed arthritis were 51% more likely to fall into income poverty than nonarthritic women. In men, arthritis was linked with a 22% increased risk. Also, women with arthritis were 87% more likely to fall into "multidimensional poverty," which includes income, health, and education attainment, while the arthritis-related risk in men was 29%. The investigators noted that given the high prevalence of ...

New findings shed light on fundamental process of DNA repair

2015-09-08
Inside the trillions of cells that make up the human body, things are rarely silent. Molecules are constantly being made, moved, and modified--and during these processes, mistakes are sometimes made. Strands of DNA, for instance, can break for any number of reasons, such as exposure to UV radiation, or mechanical stress on the chromosomes into which our genetic material is packaged. To make sure cells stay alive and multiply properly, the body relies on a number of mechanisms to fix such damage. Although researchers have been studying DNA repair for decades, much remains ...

Advanced treatment and prognosis data available for TNM classification

2015-09-08
DENVER, Colo. - The publication of the Eighth Edition of the Tumor, Node and Metastasis (TNM) Classification of Lung Cancer will provide physicians around the world access to new data to more precisely stage and treat cases of lung cancer. That data, collected by the International Association for the Study of Lung Cancer (IASLC) Staging and Prognostic Factors Committee and presented at the 16th World Conference on Lung Cancer (WCLC) in Denver on Tuesday, Sept. 8, 2015 at the Colorado Convention Center, will be published in 2016. In 1998, IASLC established its Lung Cancer ...

Study defines criteria for MET-driven lung cancer suitable for crizotinib treatment

2015-09-08
Many cancers include increased copies of the gene MET. But in which cases is MET driving the cancer and in which do these increased copies happen to "ride along" with other molecular abnormalities that are the true cause of the disease? The answer influences whether a tumor will respond to drugs that inhibit MET, like crizotinib. A University of Colorado Cancer Center study being presented today at the 16th World Conference on Lung Cancer in Denver, Colorado sheds light on the best method to determine the threshold at which MET amplification becomes clinically relevant. "Generally, ...

Flu vaccine reduces hospitalizations and deaths among nursing home residents

2015-09-08
When the influenza vaccine is well matched to the prevailing strains of flu in a given season, patients in nursing homes are significantly less likely to be hospitalized or to die of pneumonia and other influenza related causes. The finding comes from a study of more than 1 million Medicare fee-for-service long-stay nursing home residents. When the vaccine's match with A/H3N2--the influenza strain typically responsible for severe symptoms--was excellent (75%) during an A/H3N2 predominant season, there was an estimated 2.0% reduction in deaths and a 4.2% reduction in ...

Personalized medicine's success needs accurate classification of tumors

2015-09-08
DENVER, Colo. - If cancer patients are to receive optimal treatment, clinicians must have an accurate histologic classification of the tumor and know its genetic characteristics, said William D. Travis, M.D., attending thoracic pathologist, Department of Pathology, at Memorial Sloan Kettering Cancer Center in New York City. Dr. Travis made his remarks today at the 16th World Conference on Lung Cancer (WCLC) hosted by the International Association of the Study of Lung Cancer (IASLC). Dr. Travis said the pathology and oncology professions made a big step towards this goal ...

Study's findings could help expand the donor pool for liver transplantation

2015-09-08
Organ donation after circulatory death (DCD), in which transplant organs are taken from donors after ay period of no blood circulation or oxygenation, is often considered inferior to donation after brain death, in which circulation and oxygenation are maintained until organs are removed for transplantation. Currently, the use of livers from DCD donors remains controversial, particularly with donors with advanced age. A new study of DCD liver transplantations conducted at the Cleveland Clinic from 2005 to 2014 found no significant correlation between donor age and organ ...

LAST 30 PRESS RELEASES:

How your brain decides blame and punishment -- and how it can be changed

Uniquely human brain region enables punishment decisions

Pinpointing punishment

Chapman University publishes research on attractiveness and mating

E-cigarettes: Special issue from Nicotine & Tobacco Research

Placental problems in early pregnancy associated with 5-fold increased risk of OB & fetal disorders

UT study: Invasive brood parasites a threat to native bird species

Criminals acquire guns through social connections

Restoring ocean health

Report: Cancer remains leading cause of death in US Hispanics

Twin study suggests genetic factors contribute to insomnia in adults

To be fragrant or not: Why do some male hairstreak butterflies lack scent organs?

International team discovers natural defense against HIV

Bolivian biodiversity observatory takes its first steps

Choice of college major influences lifetime earnings more than simply getting a degree

Dominant strain of drug-resistant MRSA decreases in hospitals, but persists in community

Synthetic biology needs robust safety mechanisms before real world application

US defense agencies increase investment in federal synthetic biology research

Robots help to map England's only deep-water Marine Conservation Zone

Mayo researchers identify protein -- may predict who will respond to PD-1 immunotherapy for melanoma

How much water do US fracking operations really use?

New approach to mammograms could improve reliability

The influence of citizen science grows despite some resistance

Unlocking secrets of how fossils form

What happens on the molecular level when smog gets into the lungs?

Using ultrasound to clean medical instruments

Platinum and iron oxide working together get the job done

Tiny silica particles could be used to repair damaged teeth, research shows

A quantum lab for everyone

No way? Charity's logo may influence perception of food in package

[Press-News.org] Shouldering the burden of evolution
UCSF study shows how early tool use shaped our body
Press-News.org is a service of DragonFly Company. All Rights Reserved.
Issuers of news releases are solely responsible for the accuracy of their content.