"Scientists Debunk Theory on End of 'Snowball Earth' Ice Age" - Science Daily, May 26, 2011.

There was an ice age, called the Marioan ice age or 'Snowball Earth', that happened around 600 million years ago and there is a theory of why and how it came to such a sudden and abrupt end. Scientists say that it happened with "large amounts of methane, the bubbling through ocean sediments, a strong greenhouse gas, and from beneath the permafrost and heating the atmosphere."

Samples of cap dolostone in south China were found and that is the main physical evidence there is to support this theory. These are known to have less of the carbon-13 isotope than found in normal carbonate rocks. Dolostone is a type of sedimentary rock that consists of dolomite, a carbonate mineral and it is called 'cap' dolostone when it overlaps a glacial deposit. The theory states that these rocks formed when methane bubbled up from below and was oxidized by microbes, "with its carbon wastes being incorporated into the dolostone", causing the end of the ice age. This made sense because methane tends to be low in carbon-13 and if the carbon-13-depleted methane was turned into rock, that rock would also be low in carbon-13. However, this idea was quite controversial since there was no trace of previous isotopic evidence in carbonate rock as back in time as the ice age happened.

A team from the California Institute of Technology (Clatech) published an article in the journalNature saying it is wrong because of the testings they have done. Their data showed that the rock that was the main evidence that the theory was based on had formed millions of years after the ice age had ended and in temperatures so high that were unbearable for any living organism.

John Eiler, the Robert P. Sharp Professor of Geology and professor of geochemistry at Clatech, and one of the paper's authors, developed a technique used to tell the rocks' "story" that looked at the way the isotopes, like the carbon-13 in the dolostones, group together in crystalline structures like bone or rock. They proved that this grouping of isotopes in dependent to the temperature of the environment in which the crystals form; the hotter the temperatures are, the less grouping there is, and the colder the temperatures are, more grouping occurs.

"The rocks that we analyzed for this study have been worked on before," says Thomas Bristow, the paper's first author and a former postdoc at Caltech who is now at NASA Ames Research Center, "but the unique advance available and developed at Caltech is the technique of using carbonate clumped-isotopic thermometry to study the temperature of crystallization of the samples. It was primarily this technique that brought new insights regarding the geological history of the rocks."

Eiler says, "the carbon source was not oxidized and turned into carbonate at Earth's surface. This was happening in a very hot hydrothermal environment, underground." We know it happened at least millions of years after the ice age ended, and probably tens of millions. Which means that whatever the source of carbon was, it wasn't related to the end of the ice age."

This topic brings up many questions since scientists say that the only evidence there is, is the carbon-isotopic evidence of a Precambrian methane seep. Scientists are not just trying to find out how the Marinoan ice age ended, but also about the amount of methane of the Earth and the biogeochemistry of the ocean.

What interested me about this article was that, at first, when I read the title I though it was about the end of the world and I started reading the article, but then I realized what it was really about and it got me more interested. I think that it is fascinating how chemistry and geology are related because, in this case for example, they are connected by how the rock is formed and how a chemical reaction occurred for the ice age to have happened. Even though I did not understand some of the explanations about how the rock was formed since I have not studied chemistry in that level of depth, I found it quite an appealing subject and I want learn more about it. Learning about what happened 600 million years ago is very fascinating and if something like this happens again, in the future we might be going through another ice age...

http://www.sciencedaily.com/releases/2011/05/110525141540.htm

"Monkeys, Too, Can Recollect What They've Seen, Study Suggests" - Science Daily, April 29, 2011.

According a report publish on April 28, 2011, in Current Biology, monkeys are able, just like humans, to recollect memories from the past and put them together to create an image of what something used to look like. Researchers discovered that monkeys are able to recall things , such as simple objects they have seen in the past and even draw an image of them in a touch screen. They say that the memories from humans and monkeys are similar then they knew.

As the researchers say, there is a difference between recognition and recall. To recall an object is to remember what an object looks like and remember it without it being present in the moment, unlike recognition. "Recall is necessary for planning and imagining and can increase the flexibility of navigation, social behavior, and other cognitive skills."

"The ability of monkeys to recall these shapes flexibly suggests that they might be able to recollect other types of information that would be useful to them in the wild," said Benjamin Basile of Emory University. "It's exciting to speculate that they may be able to recollect the appearance of monkeys they know, what favorite foods look like, or the path they would have to take to get to a water source. Maybe it's often just easier to recognize the monkey, the food, or the landmark in front of you. What we do know is that they do seem to have the ability to recall information in the lab."

Though recall and recognition tests give to humans showed that humans use different types of memory than primates, scientists had to create different tests for primates also because primates cannot draw or talk. One of the tests created for monkeys by Basile and Robert Hampton consisted of five trained rhesus monkeys in a recall test who had to, in a touch screen, produce an image of a simple object just from their memory. Those objects included two or three boxes on a grid and then, after a short while, part of the object would appear in a different part of the screen and the monkey would have to draw the part that was missing.

In the same testing conditions, humans and monkeys showed that they do better in recognition tests than in recall tests and that their recalling ability slowly decreased and that the monkeys ability to recollect did not depend on the language and may have been present 30 million years ago in our common ancestor.

"Recollection and familiarity likely evolved because they solved functionally incompatible problems," the researchers wrote. "For example, familiarity does not support detailed memory for context, but it is quick and resistant to distraction. Recollection is slower and more vulnerable to distraction but supports a more detailed and flexible use of memory. Familiarity might better allow rapid responses to foods and predators under distracting conditions, whereas recollection might be necessary to access knowledge of distant food locations or past social interactions for planning future behavior."

I found this article interesting because I have researched about how monkeys and humans share a lot in common and I think it is fascinating. There also some studies that show that monkeys doing the same test as humans about recalling and recognizing objects do better than humans and it was also proven that monkeys have better memory than humans. Monkeys and humans share the same common ancestor about six million years ago and share DNA and monkeys outsmart humans in different tasks such as ones that involve memory. Maybe in the future monkeys and primates will rule the world...

http://www.sciencedaily.com/releases/2011/04/110428123934.htm