Peopling Asia

Current understanding of human evolution is that people originated in north Africa and migrated all around the globe. This is opposed to the belief that people originated in several different locations. What ancient routes were taken can be teased out by looking at several factors. As people spread out languages developed. Their structure can be analyzed for relationships that might hint at their origin. Cultures and traditions that developed can also show similarities.

DNA is being used to look at genetic relationships between and within populations. By looking at variation in highly conserved regions of our genome, the HUGO Pan Asian SNP Consortium determined that Asia was people by a distinct migration out of the Middle East through India.

This study laid a foundation to answer more intricate questions: what is the origin of the native Australians and when did these migrations take place.


Click here to read research article.

Darwin's Lumpers Vs Splitters

The tree of life has many branches on it. The argument about how many branches it should have is between the lumpers and the splitters. Lumpers want fewer branches, and Splitters want more. Delineating the divisions is not clear cut. Morphology, anatomy, genetics, and other characteristics are difficult to tease apart.

Currently there is disagreement on where archea should be placed. The archea are generally described as a third division of life with the other two divisions being bacteria and eukaryotes. archea are prokaryotic like bacteria (meaning they do not have membrane bound nuclei) but have other characteristics similar to eukaryotes.

However some biologists think archea should be placed in a group that includes eukaryotes. Evidence about similarities in lipid (fat) synthesis support this placement. The terminology biologists use to describe this is "archea should be placed basally in a clade with all eukaryote organisms." This means that in the tree of life archea would be a twig sprouting near the base of the eukaryote branch. While compelling, this view has yet to be embraced by mainstream biology.


Click here to read an article about Darwin and Lumpers & Splitters.

Mushroom Virsuses! Who Knew?

DNA changes in several ways. Most often we will think of mutation (if we think about DNA change at all. However there are some other ways DNA can change. Some viruses can insert their own genes, and scientists can genetically alter DNA or bio-engineer the genome.

Scientists at SUNY Buffalo have found evidence of another mechanism used to change DNA. Some viruses "borrow" the machinery from other viruses. What is surprising about this is that the infected cells then used the new DNA to make useful proteins.

If you have a strong opinion about genetic engineering, does knowing this occurs in nature influence what you think? These viruses are using these techniques to their own advantage.

Chickenpox and Herpes viruses insert their genes into human cells. If you have been infected by either one do you consider yourself genetically altered?

Click here to read the original research article.

copyright 2009 Brendan Craughwell. All rights reserved. SCIENTIFIC STATION is a trademark of Brendan Craughwell. All rights reserved.

Prosperity Vs Wealth

Click here to read research abstract

Wealth and prosperity are valued differently by cultures and individuals. This study looks at some of the factors that influence how those living in rural communities view their economic status.

How do you see your own situation? Do you live the life you desire?

Click here to see how the IRS breaks down the top wealth holders for selected years. They estimate the wealth of the living population using the Estate Multiplier technique.


copyright 2009 Brendan Craughwell. All rights reserved. SCIENTIFIC STATION is a trademark of Brendan Craughwell. All rights reserved.

Upset Stomach? Blame Your Childhood

Hygiene in childhood may actually affect adult digestive health.
Researchers at the University of Aberdeen raised genetically similar pigs in one of 3 different environments: outside, indoor, or in experimental isolators. The experimental isolators are environments that allow researchers to control what bacteria get in.
The pigs raised outside had Lactobacillus as the predominant bacteria in the tissue lining their digestive tracts. The pigs raised indoor had reduced Lactobacillus and increased numbers of potentially pathogenic bacteria in their digestive tract. This skewed ratio of gut flora was exaggerated in the pigs raised in the experimental isolators.
These differences that were observed in early life influenced the digestive health of the adult pigs. The bacteria introduced by the early outdoor environment seem to have improved the ability of the adult pigs to maintain proper immune responses in the digestive tract and limited excessive inflammation of the gut.
This work has implications for humans. The authors write in BMC Biology that recent population studies reveal that childhood hygiene is a significant risk factor for development of inflammatory bowel disease.
Its still too early though to blame adult digestive disease on early childhood exposures. The effect on adult microbial diversity and immune responses needs to be studied.

copyright 2009 Brendan Craughwell. All rights reserved. SCIENTIFIC STATION is a trademark of Brendan Craughwell. All rights reserved.

Click here to read research article

Martian Water? Sorry.

Summer on Mars is probably less habitable that previously thought. Evidence of abundant water in Martian magma or lava, may actually be caused by chlorine.

Even though we send probes to Mars pretty regularly, a lot of what we know of the planet actually comes from indirect observation. We don’t see large bodies of water on the planet, but from different observations we try to determine the amount of H2O in the atmosphere, on the surface, within rocks, and possible underground. To do this we need to look at the effect we expect water to have on these structures.

One way to measure the amount of water in the atmosphere is to determine how much infrared light is absorbed. Water vapor absorbs more than other gases. Those measurements need to be corrected for weather patterns, because those values can change frequently.

When looking at rocks, it is possible to see the effect water has had on them. In particular, water will create specific crystal patterns in the rock that can still be observed even after all the water has evaporated.

It was previously thought that Martian lava contained as much as 2% water. This was determined by looking at crystal patterns of meteors that come from Mars. 2% would provide a hefty source of H2O for the Martian water cycle.

New data published in the journal Geology suggests that these crystals were actually formed in a Chlorine rich environment on Mars. It seems as though Mars may be 2.5 times richer in Chlorine than Earth.

Click here to read the research abstract

copyright 2009 Brendan Craughwell. All rights reserved. SCIENTIFIC STATION is a trademark of Brendan Craughwell. All rights reserved.

Your Christmas Tree has got a lot more going on than just its decorations

Pine trees come in many different species. Depending on its location, how many leaves it makes and the pattern of the bark, a pine tree can be relatively easy to identify.
The closer one looks at groups of similar pine trees, it becomes harder to answer questions about how closely or distantly related they are.
Botanists have many techniques for
working out these problems, but more help is always welcome.
Researchers at Oregon State University published findings in BMC Biology that describe looking at DNA found in the chloroplast of pine trees to help differentiate populations of very similar trees.
Chloroplasts are the parts of plant cells that make the leaves green. They have their own DNA, and each tree only gets its chloroplast
from the plant that makes the seed (its mother.)
Since this DNA gives a somewhat stable reference point for analysis, because it doesn’t mix like most of the DNA found in a cell.
In their paper, Matthew Parks, Richard Cronn and Aaron Liston describe how best botanists can use this chloroplast DNA to tease out otherwise unrecognizable differences or similarities in plants.

Click here to read the original article.

copyright 2009 Brendan Craughwell. All rights reserved. SCIENTIFIC STATION is a trademark of Brendan Craughwell. All rights reserved.