Empires have risen and fallen and often it has been due to changes in the climate. When agriculture was a more demanding endeavor people wanted the most fertile lands and as that shifted, so did cities.

For that reason, climate change has often been cited as the most logical reason for a huge population collapse in Europe at the end of the Bronze Age. Now archaeologists and environmentalists say they can prove definitively that climate change could not have been the culprit. Because the changes in climate that scientists believed to coincide with the fall in population in fact occurred at least two generations later.

"Dark matter" is a blanket term for inferred matter that is undetected but must exist in order for gravity at very large scales to make any sense at all.

Based on inference, 27 percent of the universe is generally acknowledged to be dark matter, even though it is not visible and eludes direct detection and measurement. Whatever dark energy might turn out to be gets a number of about 68 percent of the universe. The rest of the universe, what we can detect and feel, is what we know to be matter. 

Scientists have found that transplanting a microbe that occurs naturally in eastern cottonwood trees boosts the ability of willow and lawn grass to withstand the effects of the industrial pollutant phenanthrene.

Because the plants can then take up 25 to 40 percent more of the pollutant than untreated plants they could be useful in phytoremediation, the process of using plants to remove toxins from contaminated sites, without all the environmentalist political lobbying drama of using genetically modified plants to do the same thing. 

Flowering dogwood (Cornus florida), kousa dogwood (Cornus kousa) and various genetically modified relatives are the most popular and economically significant members of the genus Cornus in the nursery and landscape industries. These deciduous trees are highly valued for their spring display of pink, red, or white bracts, brilliant red fall foliage, and exfoliating bark and in the US sales of dogwoods account for more than $30 million dollars each year.

What's in a name? Apparently a lot. So much so that social mobility in England hasn't changed much since pre-Industrial times.

After William the Conqueror defeated King Harold II at the Battle of Hastings in 1066, making England a French country rather than an Anglo-Saxon one, he rewarded his supporters with lands taken from those who had been loyal to his opponent. He was very good to them - but he wanted his levies. So if your name appeared in the original Domesday Book, you were going to get a tax bill, but the benefits were so substantial you are more likely to be upper class even today.

Diarrhea and candidiasis can result from taking the common antibiotic treatments, amoxicillin and amoxicillin-clavulanic acid, although harms may be underreported, according to a study published in CMAJ (Canadian Medical Association Journal).