About 10 percent of Asia can claim to be descended from Genghis Khan and they are absolutely correct, genetic studies show; the reason is that part of the benefit to rampaging across Asia, the mid-East and into Europe was a lot of sex.

But it isn't just conquering Mongols, even on a small scale violent conflict offers biological rewards to those those who take part in it, say anthropologists who correlated violent raids and combat to reproductive fitness. 

There is no question there are genetic and environmental components to cancer but a statistical model that measures the proportion of cancer incidence across many tissue types finds that cancer is caused mainly by random mutations that occur when stem cells divide.

According to scientists from the Johns Hopkins Kimmel Cancer Center, two-thirds of adult cancer incidence across tissues can be explained primarily by "bad luck," when these random mutations occur in genes that can drive cancer growth, while the remaining third are due to environmental factors and inherited genes.

The implications of their model range from altering public perception about cancer risk factors to the funding of cancer research, they say.

The most recent outbreak of the Ebola virus disease occurring in West Africa may have originated from contact between humans and virus-infected bats, according to a new study in EMBO Molecular Medicine, which identifies insectivorous free-tailed bats as plausible reservoirs and expands the range of possible Ebola virus sources to this type of bats.

The virus that spread from Meliandou into other areas of Guinea and Sierra Leone, Liberia, Nigeria and Senegal, represents the largest ever-recorded Ebola outbreak killing 7,800 people as of December 17th 2014. 

New prostate screening guidelines recommend that the prostate-specific antigen (PSA) test not be used to screen for prostate cancer based on evidence that shows uncertain benefits and   an increased risk of harm. 

Prostate cancer is the most commonly diagnosed non-skin cancer in men and the third most common cause of death from cancer in men in Canada and elsewhere. In modern times, the prognosis for most prostate cancers is good with a 10-year survival rate of 95%. Prostate cancer is generally slow to progress and today is usually not life-threatening. 

When the clock strikes midnight on New Year's Eve, champagne bottles get popped all around the world.

So what is it exactly that sends that cork flying? And what's the best way to pour your bubbly?

Credit: The American Chemical Society

This week, Reactions gives you plenty of champagne facts and tips to impress your fellow partygoers as you ring in the New Year.

Subscribe to the series at Reactions YouTube

Binge drinking in young, healthy adults significantly disrupts the immune system, according to a new epidemiology paper.