Archive for Evolution
Earlier this week we reported on a neurological implant that has been found to accurately predict the onset of epileptic seizures. But a discovery by researchers at the University of California, San Francisco (UCSF) could one day render such a device obsolete. By transplanting a specific type of cell into the brain, the researchers have been able to cure epilepsy in adult mice, with hopes a similar treatment could work in humans.
Birds may have more in common with dinosaurs than we once thought. Paleontologists have discovered a small North American dinosaur that incubated its eggs in a similar way to brooding birds. (Photo : Flickr/Benoit Dupont)
Birds may have more in common with dinosaurs than we once thought. Paleontologists have discovered a small North American dinosaur that incubated its eggs in a similar way to brooding birds. The finding could point to a strong, evolutionary link between the two.
How dinosaurs cared for and hatched their young has baffled paleontologists for years. It’s possible that they buried their eggs in nest materials like crocodiles, or placed them in open nests like brooding birds. Until now, though, researchers weren’t sure which theory was most likely.
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Using clutches found in Alberta and Montana, researchers closely examined the shells of the fossil eggs found within them. The eggs themselves were laid by a small, meat-eating dinosaur called Troodon. Existing around the Late Cretaceous period, this creature ranged widely; its fossils can be found all the way from Texas to Alaska. Possessing one of the largest known brains of any dinosaur group relative to its body mass, this creature also possessed large eyes that were slightly forward facing, which probably aided in hunting.
After examining the eggs, the researchers found that only the bottoms of them would have been buried in mud while the tops would have stuck out vertically. It turned out that, like brooding birds, this particular dinosaur did not bury its eggs.
“Both the eggs and the surrounding sediments indicate only partial burial,” said Darla Zelenitsky, co-author of the paper recording the study, in a press release. “Thus an adult would have directly contacted the exposed parts of the eggs during incubation.” read more: http://goo.gl/J7LJu
In the hope of reconstructing a pivotal step in evolution — the colonization of land by fish that learned to walk and breathe air — researchers have decoded the genome of the coelacanth, a prehistoric-looking fish whose form closely resembles those seen in the fossils of 400 million years ago.
Often called a living fossil, the coelacanth (pronounced SEE-luh-canth) was long believed to have fallen extinct 70 million years ago, until a specimen was recognized in a fish market in South Africa in 1938. The coelacanth has fleshy, lobed fins that look somewhat like limbs, as does the lungfish, an air-breathing freshwater fish. The coelacanth and the lungfish have long been battling for the honor of which is closer to the ancestral fish that first used fins to walk on land and give rise to the tetrapods, meaning all the original vertebrates and their descendants, from reptiles and birds to mammals.
The decoding of the coelacanth genome, reported online Wednesday in the journal Nature, is a victory for the lungfish as the closer relative to the first tetrapod. But the coelacanth may have the last laugh because its genome — which, at 2.8 billion units of DNA, is about the same size as a human genome — is decodable, whereas the lungfish genome, a remarkable 100 billion DNA units in length, cannot be cracked with present methods. The coelacanth genome is therefore more likely to shed light on the central evolutionary question of what genetic alterations were needed to change a lobe-finned fish into the first land-dwelling tetrapod. read more: http://goo.gl/KY4uA
(Reuters) – A 2 million-year-old ancestor of man had a mixture of ape and human-like features that allowed it to hike vast distances on two legs with as much ease as it could scurry up trees, according to research published on Friday.
Discovered in cave near Johannesburg in 2008, the fossils of a species named “Australopithecus sediba” have given researchers clues about the evolution of man and which traits in our ancestors fell by the wayside.
Standing about 1.3 meters (4 ft) tall, sediba had a narrow rib cage similar to apes but a flexible spine more similar to that of a human. Its long arms and powerful torso helped in climbing, according to the research published in the journal Science.
Sediba’s small heel resembled a chimpanzee’s and it walked with an inward rotation of the knee and hip on slightly twisted feet with a flat-footed gait that would have helped it cover ground, the researchers said.
“It is the perfect compromise of something that has the need to walk on the ground efficiently for long distances. At the same time, it is a very capable climber,” said Lee Berger, project leader at the Wits Evolutionary Studies Institute in South Africa.
The researchers plan further studies to see how these fossils of early human relatives known as hominin compare to other remains, to help put together the pieces of evolution.
“We have more complete specimens of fossils than for any other early hominin species that has ever been discovered. What this means is that we can make assessments of the anatomy and behavior of this species with a great deal of confidence,” Berger told Reuters.
A real-life “tractor beam”, which uses light to attract objects, has been developed by scientists.
It is hoped it could have medical applications by targeting and attracting individual cells.
The research, published in Nature Photonics and led by the University of St Andrews, is limited to moving microscopic particles.
In science fiction programmes such as Star Trek, tractor beams are used to move much more massive objects.
It is not the first time science has aimed to replicate the feat – albeit at smaller scales.
Scientists have stored audio and text on fragments of DNA and then retrieved them with near-perfect fidelity
Scientists have stored audio and text on fragments of DNA and then retrieved them with near-perfect fidelity—a technique that eventually may provide a way to handle the overwhelming data of the digital age.
The scientists encoded in DNA—the recipe of life—an audio clip of Martin Luther King Jr.’s “I Have a Dream” speech, a photograph, a copy of Francis Crick and James Watson’s famous “double helix” scientific paper on DNA from 1953 and Shakespeare’s 154 sonnets. They later were able to retrieve them with 99.99% accuracy. http://goo.gl/xMueJ
The experiment was reported Wednesday in the journal Nature
Time for a field trip for those in Texas, Kansas, etc who don’t believe evolution exists?
Using a process called paleo-experimental evolution, Georgia Tech researchers have resurrected a 500-million-year-old gene from bacteria and inserted it into modern-day Escherichia coli (E. coli) bacteria. This bacterium has now been growing for more than 1,000 generations, giving the scientists a front row seat to observe evolution in action.
“The altered organism wasn’t as healthy or fit as its modern-day version, at least initially,” said Gaucher, “and this created a perfect scenario that would allow the altered organism to adapt and become more fit as it accumulated mutations with each passing day.”
The growth rate eventually increased and, after the first 500 generations, the scientists sequenced the genomes of all eight lineages to determine how the bacteria adapted. Not only did the fitness levels increase to nearly modern-day levels, but also some of the altered lineages actually became healthier than their modern counterpart.
Forty-six percent of Americans believe that God created humans in their present form at one point within the past 10,000 years, according to a survey released by Gallup on Friday.
That number has remained unchanged for the past 30 years, since 1982, when Gallup first asked the question on creationism versus evolution. Thirty years ago, 44% of the people who responded said they believed that God created humans as we know them today – only a 2-point difference from 2012…
Leading scientists are now saying that dinosaur flatulence may have been partially responsible for climate change in pre-historic times. Some are going so far as to say that it may have been so catastrophic that it helped lead to the dinosaur’s eventual extinction.
The Daily Mail elaborates:
Professor Graeme Ruxton of St Andrews University, Scotland, said the giant animals spent 150 [million] years emitting the potent global warming gas, methane.
Large plant-eating sauropods would have been the main culprits because of the huge amounts of greenery they consumed.
The team calculated the animals would have collectively produced more than 520m tons of methane a year – more than all today’s modern sources put together.
It is thought these huge amounts could easily have been enough to warm the planet.
One of the animals, a 90-ton argentinosaurus, which measured 140ft in length, would have consumed at least half a ton of food in one day.
After breaking down in the animal’s stomach it would have produced thousands of [liters] of the greenhouse gas compared with a modern cow which only produces 200 [liters] of methane daily.
‘In fact, our calculations suggest these dinosaurs may have produced more methane than all the modern sources, natural and human, put together,’ said [Ruxton's co-researcher David] Wilkinson to the Sunday Times.