Link between cancer and human evolution revealed

Washington, July 3 (ANI): A new study conducted by researchers at Ben-Gurion University of the Negev (BGU) suggests a link between cancer and human evolution.

Writing about their work in the journal Genome Research, the researchers say that gene mutations that once helped humans survive may increase the possibility for diseases, including cancer.

They came to this conclusion after studying mutations in the genome of the mitochondria, a part of every cell responsible for energy production that is passed exclusively from mothers to their children.

The mitochondria are essential to every cell’s survival and our ability to perform the functions of living.

“Our ancestors responded to environmental changes, such as climate shift, with mutations that increased their chances of survival. But today, these same mutations predispose us toward complex diseases such as cancer,” says Dr. Dan Mishmar, a molecular biologist from the Department of Life Sciences at BGU.

“Although mitochondria’s role in the emergence of new species has been investigated recently, the idea that they are responsible for our susceptibility to illness startles many,” Dr. Mishmar adds.

During the study, the research team analysed the genome mitochondria mutations from 98 unrelated individuals.

According to them, combinations of mutations tended to occur in tumours in precisely the same DNA building blocks that changed during evolution.

The researchers also observed that the mitochondrial genome of humans, who had migrated out of Africa to Europe 100,000 years ago, carried seven mutations found in almost all of today’s Europeans.

“The concept that the same principles that drive evolution toward the emergence of new species govern the emergence of diseases is new.

A clinician looks at the genome of a tumor, or other disease, and compares it to the normal population, looking for new mutations that do not occur there. I assume the mutations are already part of the population and have had a survival function. When these same mutations reoccur in the correct environment, they can cause disease,” Dr. Mishmar says.

The team say in the research article: “We show, strikingly, that evolution repeated itself in cancer.

If we better understand how evolution moved, we can understand the genetic basis of many complex disorders. Since mitochondria play a central role in disease, if we understand how they work and the way they changed our ability to survive in different conditions in ancient times, we can understand the mechanics of the disease.

And we’ll understand a lot about the way certain people develop diseases and others have a lower tendency toward those same diseases. This may lead to new methods of disease prevention or cures.” (ANI)

Huge CO2 releases may have amplified global warming at end of last ice age

Washington, March 13 (ANI): A new research has suggested that natural releases of carbon dioxide from the Southern Ocean due to shifting wind patterns could have amplified global warming at the end of the last ice age, and could be repeated as manmade warming proceeds.

The research was conducted by a team of scientists at Columbia University’s Lamont-Doherty Earth Observatory, US.

Many scientists think that the end of the last ice age was triggered by a change in Earth’s orbit that caused the northern part of the planet to warm.

This partial climate shift was accompanied by rising levels of the greenhouse gas CO2, ice core records show, which could have intensified the warming around the globe.

Now, the team from Lamont-Doherty Earth Observatory has offered one explanation for the mysterious rise in CO2.

According to them, the orbital shift triggered a southward displacement in westerly winds, which caused heavy mixing in the Southern Ocean around Antarctica, pumping dissolved carbon dioxide from the water into the air.

“The faster the ocean turns over, the more deep water rises to the surface to release CO2,” said lead author Robert Anderson, a geochemist at Lamont-Doherty. “It’s this rate of overturning that regulates CO2 in the atmosphere,” he added.

In the last 40 years, the winds have shifted south much as they did 17,000 years ago, said Anderson.

If they end up venting more CO2 into the air, manmade warming underway now could be intensified.

Two years ago, J.R. Toggweiler, a scientist at the National Oceanic and Atmospheric Administration (NOAA), proposed that westerly winds in the Southern Ocean around Antarctica may have undergone a major shift at the end of the last ice age.

This shift would have raised more CO2-rich deep water to the surface, and thus amplified warming already taking place due to the earth’s new orbital position.

Anderson and his colleagues are the first to test that theory by studying sediments from the bottom of the Southern Ocean to measure the rate of overturning.

According to the scientists, changes in the westerlies may have been triggered by two competing events in the northern hemisphere about 17,000 years ago.

The earth’s orbit shifted, causing more sunlight to fall in the north, partially melting the ice sheets that then covered parts of the United States, Canada and Europe.

“Now I think this really starts to lock up how the CO2 changed globally,” said Toggweiler. “Here’s a mechanism that can explain the warming of Antarctica and the rise in CO2. It’s being forced by the north, via this change in the winds,” he added. (ANI)

North Atlantic Ocean is world’s ‘climate superpower’

London, Feb 18 (ANI): New studies have shown that the North Atlantic Ocean is definitely the ‘climate superpower’ of the world, with its ability to control global weather systems.

In past studies, Anastasios Tsonis and colleagues at the University of Wisconsin-Milwaukee have shown statistically that climate features like El Nino and the North Atlantic Oscillation (NAO), which drives weather across Europe, become synchronised for a few decades, before the links abruptly break down and a new pattern emerges.

They call it “synchronised chaos”.

Now, according to a report in New Scientist, their modelling studies have shown the action is always driven from the North Atlantic Ocean (NAO).

Tsonis said that the NAO is “without exception the common ingredient… the pacemaker of major climate shifts.”

The region also happens to be especially sensitive to the effects of climate change, so what is happening there could affect the world.

The findings may be seized on by deniers of man-made climate change as evidence of the scale of natural climate variability.

Tsonis argued two years ago that accelerated global warming since the 1970s could be due partly to a natural climate shift.

But, the findings will leave most climate scientists more worried.

Today’s climate is changing most dramatically in the far North Atlantic, with record warming and ice loss in recent years.

If the climate’s “tipping point” resides in these waters, then nature’s synchronised chaos could unleash unexpectedly sudden and severe consequences.

If the climate’s tipping point resides in these waters, there could be severe consequences. (ANI)