(Press-News.org) Research conducted by Sandy Kawano and Richard Blob at Clemson University compared terrestrial locomotion in tiger salamanders and mudskipper fish, which have similar characteristics to early tetrapod ancestors.
The researchers filmed these organisms as they walked over a force platform which measures forces like a bathroom scale but separates them into 3 directions (upward, fore-aft, and side-to-side). They compared the forces experienced by the pectoral fins of the mudskipper fishes to the forelimbs and hind limbs of walking tiger salamanders. The results showed that that mudskippers' pectoral fins experience more medial forces than the limbs of salamanders, and that the forelimbs could have a played a similar weight-bearing role as the hind limbs.
Sandy Kawano said: "The transition from fins to limbs marks the most dramatic change in orientation of the locomotor forces from contact with the ground. Using these data we can now evaluate the locomotor capabilities of numerous important fossil taxa that spanned the water-to-land transition in tetrapod evolution. We hypothesise that the medial orientation of the forces on pectoral fins would result in unreasonably high bone stresses in early amphibious fish with fins, which would explain why the evolutionary invasion of land by vertebrates was accomplished instead by tetrapods with limbs with digits."
INFORMATION:
The evolution of fins to limbs in the land invasion race
2013-07-06
ELSE PRESS RELEASES FROM THIS DATE:
Muscle power: Bats power take-off using recycled energy
2013-07-06
Dr Nicolai Konow (Brown University, USA), who led the research said: "Energy is stored in the triceps tendon, which is used to power elbow extension – in essence, elbow extension happens using "recycled" energy. State of knowledge, and our results, indicates that bats are unique among small mammals in stretching their tendons, as small mammal limb tendons are thought to be too thick and stiff to be stretched."
"By combining information about skeletal movement with information about muscle mechanics, we found that the biceps and triceps tendons of small fruitbats are stretched ...
New study reveals important role of insulin in making breast milk
2013-07-06
Why do so many mothers have difficulty making enough milk to breastfeed? A new study by scientists at Cincinnati Children's Hospital Medical Center and the University of California Davis adds to their previous research implicating insulin's role in lactation success.
The study is the first to describe how the human mammary gland becomes highly sensitive to insulin during lactation. It is also the first study to get an accurate picture of how specific genes are switched on in the human mammary gland during lactation.
The researchers used next generation sequencing ...
Caltech researcher sheds light on M.O. of unusual RNA molecules
2013-07-06
The genes that code for proteins—more than 20,000 in total—make up only about 1 percent of the complete human genome. That entire thing—not just the genes, but also genetic junk and all the rest—is coiled and folded up in any number of ways within the nucleus of each of our cells. Think, then, of the challenge that a protein or other molecule, like RNA, faces when searching through that material to locate a target gene.
Now a team of researchers led by newly arrived biologist Mitchell Guttman of the California Institute of Technology (Caltech) and Kathrin Plath of UCLA, ...
How the brain creates the 'buzz' that helps ideas spread
2013-07-06
How do ideas spread? What messages will go viral on social media, and can this be predicted?
UCLA psychologists have taken a significant step toward answering these questions, identifying for the first time the brain regions associated with the successful spread of ideas, often called "buzz."
The research has a broad range of implications, the study authors say, and could lead to more effective public health campaigns, more persuasive advertisements and better ways for teachers to communicate with students.
"Our study suggests that people are regularly attuned ...
University of Akron researchers explore biomedical uses for hydrogels
2013-07-06
It's squishy, synthetic, flexible, mostly water and almost as tough as rubber.
No, it's not "flubber" — it's a hydrogel, and now scientists at The University of Akron are exploring new biomedical uses for this polymer-based product.
Dr. Jie Zheng, associate professor of chemical and biomolecular engineering, and Dr. Robert Weiss, Hezzleton E. Simmons professor and chair of polymer engineering, are among the most recent to contribute to the growing research of hydrogels, the gelatinous substance that, because of its toughness and plasticity, has several biomedical applications, ...
Satellites see ups and downs of 2 tropical Eastern Pacific systems
2013-07-06
There are two tropical cyclones in the Eastern Pacific Ocean on July 5 and one is powering up and one is powering down. NOAA's GOES-15 satellite captured Tropical Depression Dalila and Tropical Storm Erick, both off the western coast of Mexico. Because Erick is strengthening and is close to the coast, tropical storm warnings have gone into effect for Mexico.
Tropical Depression Dalila has weakened from a Category 1 hurricane status and is expected to dissipate in the next day or two. Meanwhile, Tropical Storm Erick grew from a low pressure area called System 97E into ...
Satellite quilt of wildfires, smoke throughout Canada
2013-07-06
NASA's Aqua satellite captured multiple images of fire and smoke from Canadian wildfires on July 4, 2013. The images were stitched together to form a visual quilt.
The Moderate Resolution Imaging Spectroradiometer instrument that flies aboard Aqua captured the images. MODIS has the ability to detect hot spots (fires), which appear red in the image. Plumes of smoke from various wildfires can be seen blowing across many of the Canadian provinces and out over the Atlantic Ocean.
As of July 5, the government of Saskatechewan reported 17 wildfires. British Columbia has ...
Cosmetic surgery to look whiter fails to boost women's self-esteem
2013-07-06
Many black or racially mixed women in Venezuela are undergoing nose jobs in an effort to look whiter, but the procedure only temporarily improves their self-esteem and body image in a culture that values whiteness, a Dartmouth College study finds.
Cosmetic surgery is increasingly common in many countries, including Venezuela, where an obsession with physical appearance prompts many women to get breast implants, face lifts, liposuction and other cosmetic procedures. But the trend has also sparked controversy -- the late Venezuelan President Hugo Chavez blamed cosmetic ...
Designer droplets with 'pupils' open a world of possibilities
2013-07-06
Researchers have designed droplets using a technique that could have applications for everything from extracting oil from wells to creating makeup and food.
You've seen Hollandaise sauce or mayonnaise that has separated, or that shiny layer of oil that forms on top of skin cream. This mixture of water and oil is called an emulsion, but it can be difficult to keep emulsions from separating. A special substance called an emulsifier is used to keep the mixture stable and prevent separation.
This is an ongoing problem for the food and medical industries, as well as for ...
New insights concerning the early bombardment history on Mercury
2013-07-05
The surface of Mercury is rather different from those of well-known rocky bodies like the Moon and Mars. Early images from the Mariner 10 spacecraft unveiled a planet covered by smooth plains and cratered plains of unclear origin. A team led by Dr. Simone Marchi, a Fellow of the NASA Lunar Science Institute located at the Southwest Research Institute (SwRI) Boulder, Colo., office, collaborating with the MESSENGER team, including Dr. Clark Chapman of the SwRI Planetary Science Directorate, studied the surface to better understand if the plains were formed by volcanic flows ...