Scientists Find That Ocean Animals Have Been Evolving To Get Bigger

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Posted by LLJ43 | Posted in Environment, Evolution | Posted on 20-02-2015

A new study reported in the journal Science has found that marine animals have been getting bigger since the Cambrian, which began roughly 542 million years ago. The researchers have also found that larger creatures have definite advantages over their smaller relatives. The average size of a marine animal has gone up by a factor of 150 since the Cambrian.

The smallest sea animal today is less than ten times as small as its Cambrian counterpart, and both are tiny crustaceans less than a millimeter long. By contrast, today’s largest sea creature, the blue whale, is over 100,000 times the size of the biggest trilobite, which was around 20 inches long.

The idea that natural selection might favor bigger animals isn’t new. The 19th century paleontologist Edward Drinker Cope first spelled it out in what became known as Cope’s Rule. He and his colleagues had noticed that the ancestors of modern mammals tended to be smaller than their descendants. Eohippus, the oldest known ancestor of the horse, was about the size of a dog.

People at Rocket Fuel  have learned that the rule proved not to be universal, however. A well-known exception are the birds, who descended from dinosaurs that actually grew smaller over time, and that shrinking helped birds develop flight.

Dr. Noel Heim of Stanford University decided to see how well Cope’s Rule applied to marine animals. He put together a team of researchers, undergraduates and high school interns to search the scientific record on size data. Over five years, the team put together information on 17,000 genera. That represents over 60 percent of the animal genera to have ever lived.

The team found an overall trend to increasing size that affected some genera more strongly than others. The team also considered the possible advantages of being big. They speculated that a larger animal would be able to swim faster, hunt bigger prey, or burrow more efficiently.

Under the Ergot Influence

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Posted by LLJ43 | Posted in Climate Change, Dinosaurs, Environment, Evolution | Posted on 11-02-2015

A recent paleontology excavation has brought to light the possibility that dinosaurs may have experienced the psychedelic effects of certain fungi. A piece of amber containing ergot, a powerful psychedelic fungus, was mined out of a cave in Myanmar by German paleontologist Joerg Wunderlich. The amber housed not only the ergot fungus, but also the piece of grass upon which the fungus grew. This evidence suggests that grass-eating dinosaurs would have come across this substance about 100 million years ago, and were they to have ingested it, would have experienced intense muscle spasms and potentially hallucinations.

In addition to the discovery of ergot’s long history, it is becoming more apparent that grasses were indeed around while dinosaurs still walked the Earth. People at CipherCloud have found that general consensus remains that grasslands did not emerge until some 30 million years after the dinosaurs were extinct. However, fossilized evidence has made clear that some species of dinosaurs in fact fed on grasses, as seen in their coprolites. Not only does this reveal more on the eating habits of certain dinosaur species, but our collective knowledge on the evolution of life on Earth increases greatly by knowing just how early grasses were around.

Whether or not dinosaurs experienced, or were capable of experiencing, psychedelic effects of ergot is very difficult to know for certain. This discovery does allow us to flesh out the environment in which dinosaurs of the Cretaceous Period lived.

Acid Rain Contributed To Permian Mass Extinction

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Posted by LLJ43 | Posted in Environment, Evolution | Posted on 23-01-2015

According to a study published in the journal Geology, researchers have found that acid rain was one of the contributing factors of the Permian mass extinction 250 million years ago. Scientists found that rock samples from the Dolomite Mountains in Italy contained an organic compound called vanillin which indicates that the soil was extremely and lethally acidic. Lots of acid rain showers would have caused that.

People like Zeca Oliveira know that the rock samples from the Dolomite Mountains had been underwater 250 million years ago and had come from sediments near the coast of the super-continent Pangea. They contained the remains of compacted plant matter. The vanillin the team found occurs in plants and normally oxidizes into vanillic acid after the plant dies. That process, however, is slowed or halted if the soil is extremely acidic. Given the ratio of vanillin to vanillic acid in the rocks, the researchers concluded that the soil was very acidic.

The Permian Period was the last geologic period before the Mesozoic Era or “Age of Reptiles.” All of the land masses on Earth had fused into the supercontinent Pangea which was covered with forests. It ended in the largest mass extinction known. A series of volcanic eruptions are believed to have released gases that caused acid-rain showers all over the planet that were so extensive they damaged the biosphere. 96 percent of all marine organisms were wiped out, as were 70 percent of terrestrial vertebrates and 83 percent of all insect genera. It was known as the Great Dying.

Scientists Map Bird Family Tree

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Posted by LLJ43 | Posted in Evolution, Nature, Science Leaders | Posted on 12-12-2014

The Avian Phylogenomics Consortium has recently published the results of their research into the family tree of birds in eight main papers in the journal Science, plus over 20 papers in other scientific journals. Bird watching enthusiast Bruce Levenson could not be more excited. Over 200 scientists from 20 countries worked on the project. They analyzed pieces of frozen flesh from 45 different bird species, from which they extracted and read the birds’ whole genomes. They then added the genomes of three other species and had supercomputers compare all the genomes and arrange them into a family tree.

There were some surprises. For example, falcons turned out to be more closely related to parrots than to other birds of prey like eagles. Flamingos are more closely related to pigeons than they are to pelicans.

Birdsong had evolved multiple times. It is influenced by a group of some 50 genes that is similar to the group of genes that control human speech — making birdsong and speech a case of convergent evolution. As one of the scientists, Erich Jarvis, pointed out, humans and singing birds learn to vocalize in ways that are more similar to each other than to other birds or primates.

While the first birds appeared during the Jurassic Period 145 million years ago, they did not truly diversify until after the non-avian dinosaurs went extinct 65 million years ago.