High up in the high Andes mountains of Argentina, a population has adapted to tolerate the toxic chemical arsenic. 

For thousands of years, in some regions of the Andes, people have been exposed to high levels of it, because arsenic in volcanic bedrock is released into the groundwater.

How could this population adapt to tolerate arsenic, a potent killer of such ill repute that it's often the overused plot-driver of many murder mysteries? 
A partial human skull found in northern Israel  excited paleontologists because it seemed to hold clues about when and where humans and Neanderthals might have interbred.

The Manot Cave is a natural limestone formation that had been sealed for 15,000 years. It was discovered by a bulldozer clearing the land for development and the partial skull, sitting on a ledge, was found by spelunkers exploring the newly-opened cave. Five excavation seasons uncovered a rich deposit, with stone tools and stratified occupation levels covering a period of time from 55,000 to 27,000 years ago. 

One day something will outgrow the blue whale – but it won't be another whale. EPA

When life on Earth began around 3.6 billion years ago, all organisms were small.

Indeed, it took some 2.5 billion years to evolve any organism that grows larger than a single cell.

Since then, things have accelerated a bit and – along with the great diversification of body forms – animals have tended to get bigger. Indeed, the largest animal ever to live, the blue whale, is still very much with us, and has been swimming the world’s oceans for only a couple of million years – a mere blink of the eye in the long, long history of life in the sea.

Caring for offspring is unequal between the sexes in many animal species and a new study suggests evolution is the culprit.

Making babies is one of the fundamental conflicts of interest between the sexes. Care by either partner is beneficial to both partners as it increases the health and survival prospects of the common young, while providing care is costly only to the caring individual. As a result, each partner does best in a situation where most of the care is provided by the other partner--an outcome that is clearly impossible.
A fossil discovery has provided a missing link that helps to resolve a more than 5-million-year gap in fur seal and sea lion evolutionary history.

This new genus and species of fur seal has been called Eotaria crypta. Eotaria means 'dawn sea lion'. The species was tiny, with adults being only slightly larger than a sea otter and around the size of a juvenile New Zealand fur seal, according to University of Otago graduate student Robert Boessenecker, who found the fossil while looking through the John D. Cooper Archaeological and Paleontological Center. 
In modern culture, people are taught not to settle. Settling is, of course, subjective and people change so when psychologists are in charge, there are a lot of divorces.

What about when science was in charge? Is it better to settle or hold out for the best mate?

A new evolutionary biology study says that it's better to settle for Mr. Okay than hold out for Mr. Right. And that may be why it is in our nature - traced back to the earliest humans - to take the safe bet when stakes are high, such as whether or not we will mate.

Fish vision just got more complex. Janderk, CC BY-SA

By William Feeney, University of Cambridge

A recently published study offers new clues about the evolution of the immune system in European populations of the plant Arabidopsis thaliana and the underlying genetic mechanisms associated with immunity. 
The species Arabidopsis thaliana, which is naturally distributed across the northern hemisphere, belongs to the same family than mustard. The species is used as model in plant biology studies because its genome is relatively small and appropriate for genetic studies.

A study using geckos has found that evolution can downgrade or entirely remove adaptations that have been previously acquired, giving the species new survival advantages. 

In many species of plants and animals, individuals from the same population often come in different color variants. It's always been that way but why one color doesn't eventually replace the others through natural selection is something of an evolutionary biology mystery.

Namely, how and why do variants of the same animal exist in nature? In theory, different color morphs (variants) should be equally subjected to natural selection.