New research distinguishes for the first time a key reason for declining muscle repair during aging and a way to stop this process in mice using a certain drug.  This groundbreaking study, published in Nature, explains why muscle mass decreases with age, an important factor in weakness, causing lack of mobility and falls in elders.

Previous research has told us that stem cells can play a crucial role in stimulating muscle regeneration. This particular study looked at stem cells found in muscles that are responsible for repairing injuries and why the muscles’ capacity of regeneration deteriorates with age.

An inactive supply of stem cells is present inside every muscle, ready to be put into action by exercise or injury to fix any damage. When these stem cells are needed, they can divide into hundreds of new muscle threads and repair the injured muscle. At the end of the repairing process, a few of these cells refill the supply of dormant stem cells, enabling the muscle to carry on repairing itself continuously.

Researchers used elderly mice to conduct this study and found the number of inactive stem cells in the extra pool decreases with age, explaining the decline in the muscle’s ability to regenerate and repair as the body gets older. When these muscles were examined, the scientists found high levels of FGF2, a protein that has the capacity to trigger the division of cells. While stimulating inactive cells to split and repair muscle is a normal and vital process, they found FGF2 could awaken the dormant stem cells even when they were not needed. Continuous activation of the dormant stem cells meant depletion of the surplus, leaving the muscles without necessary stem cells when repair was really needed.

After this finding, the team attempted to obstruct FGF2 in old muscles in order to prevent the stem cell surplus from being activated unnecessarily. By giving the mice a common FGF2 inhibitor drug, they were able to slow down the decline in the number of muscle stem cells.

Preventing or reversing muscle wasting in old age in humans is still a way off, but this study has for the first time revealed a process which could be responsible for age-related muscle wasting, which is extremely exciting. The finding opens up the possibility that one day we could develop treatments to make old muscles young again. If we could do this, we may be able to enable people to live more mobile, independent lives as they age.

From Medical News Today 

 Our universe has more stars than words spoken or written by all of mankind throughout the total sum of human history.  This is especially impressive if you consider that over the course of an 80 year lifespan a human will speak around 400 million words. 

The Gaskiers ice age ended around 580 million years ago. It was very likely the most severe ice age the world has ever seen, with glaciers at sea level within ten degrees of the equator. Up until this point, microbial life, and especially bacteria had dominated the world. Following this period came the so-called Cambrian explosion, a period where most of the animal types that survive to this day rather suddenly (in geological terms) start appearing in the fossil record. This is when things that somewhat resemble macroscopic life as we know it begin to appear.

The Cambrian starts around 542 million years ago. In between the end of the Gaskiers and the start of the Cambrian was a brief 38 million year period called the Ediacara, and there exist an intriguing class of fossils    from this era, the Ediacara biota, represented to the right by Dickinsonia costata.

Although multicellular algae had existed for quite some time before, the Ediacara biota represent the first time complex, macroscopic life measured in centimeters and meters evolved on Earth. They were soft-bodied, mostly immobile creatures luckily preserved in sediment, by microbial mats or under beds of volcanic ashes. Fossils have been found on five continents. And these aren’t your ordinary fossils: they’re utterly weird, some of them almost resembling familiar life forms, others “fractal constructions unknown in our modern world.”

The climate changes following the breakup of Rodinia put extra pressure on life to evolve new forms. What evolution came up with was the marine life that evolved into the animal kingdom we know today. When the Ediacaran fossils were first discovered, they were held to be early examples of extant phyla, many of them probably a kind of “prehistoric jellyfish”. But in recent decades, this view has been challenged: the Ediacara have proven much more difficult to put into the existing hierarchies of life. Scientists no longer think all the fossils from this period fit under one umbrella; rather, each specimen is up for grabs.

Some of them are now thought to represent the dawn of animal life, related to sponges and cnidaria (corals, jellyfish, sea anemones, etc.). But we are close in time here to the hypothesized common ancestor of all animal life, and some of the Ediacara may not be rightfully classified as animals at all. The most intriguing of them may actually represent “failed evolutionary experiments”—branches of life that evolved separately from both the prokaryotes and the ancestors of today’s animal and plant life, but that eventually died out:

Perhaps the best example of an extinct high-level taxonomic group is that of the rangeomorphs, a group of colonial organisms that exhibited a modular construction of similar, highly fractal elements. These elements were combined as modules to construct frond-, spindle-, comb-, or bush-shaped colonies that filled most niches in the Mistaken Point ecosystem. Rangeomorph communities are most similar to those of modern, suspension-feeding animals, but it is difficult to relate rangeomorph morphology to any modern animals, and they appear to represent a “forgotten” architecture and construction that may represent an extinct phylum-level stem-group near the base of animal evolution. Rangeomorphs characterized the early stages of Ediacaran evolution, perhaps because their fractal growth and modular construction required less genetic complexity than was required by other animal phyla. Rangeomorphs were unable to compete with later, more highly evolved animals, and occur only rarely in younger Ediacaran assemblages and are not known from any Cambrian or younger assemblages including fossil Lagerstätten.

Right on the border between the Ediacaran and Cambrian periods, around 542 million years ago, the Ediacaran fossils disappear. Vanished from the fossil record. Perhaps they all died out due to some ecological disaster, possibly a temporary drop in oxygen levels, leaving a gaping ecological hole for the conventional animals of the Cambrian explosion to fill. Perhaps the conditions that preserved these proto-animals (which did not have skeletons) disappeared, and the creatures lived on for some time unrecorded in the fossil record. Possibly the most likely explanation is that with the Cambrian explosion, predators started appearing, and primitive, immobile and defenseless creatures such as the Ediacara biota may have been easy targets, driven to extinction by the evolutionary cousins that would replace them.

Source The Ediacara Biota: Neoproterozoic Origin of Animals and Their Ecosystems by Guy M. Narbonne, Queens University, Canada.

Mike the Headless Chicken was a Wyandotte chicken that lived for 18 months after his head had been cut off. Thought by many to be a hoax,    the bird’s owner took him to the University of Utah in Salt Lake City to establish the facts of the story.

On September 10, 1945, farmer Lloyd Olsen of Fruita, Colorado, United States had his mother-in-law around for supper and was sent out to the yard by his wife to bring back a chicken. Olsen chose a five-and-a-half-month-old cockerel named Mike. The axe missed the jugular vein,     leaving one ear and some of the brain stem intact.

Despite Olsen’s botched handiwork, Mike was still able to balance on a perch and walk clumsily; he even attempted to preen and crow, although he could do neither. After the bird did not die, a surprised Mr. Olsen decided to continue to care permanently for Mike, feeding him a mixture of milk and water via an eyedropper; he was also fed small grains of corn.

When used to his new and unusual center of mass, Mike could easily get himself to the highest perches without falling. His crowing, though, was less impressive and consisted of a muffled gurgling sound made in his throat.

Mike was on display to the public for an admission cost of twenty five cents. At the height of his popularity, the chicken earned US$4,500 per month ($48,000 in 2010 dollars).  Olsen’s success resulted in a wave of copycat chicken beheading, but no other chicken lived for more than a day or two.

From Wikipedia