Humans use a wide range of cues, both verbal and non-verbal, to communicate different emotions.

But vocalizing some positive emotions may be a socially learned behavior, as opposed to a product of evolution, according to a new study in PNAS that looked at non-verbal emotional vocalizations in two different cultural groups.

Our genes may not be the basis for human individuality, according to new studies in Science and Nature. The key may actually lie in the sequences that surround and control our genes.

The interaction of those sequences with a class of proteins, called transcription factors, can vary significantly between two people and are likely to affect our appearance, our development and even our predisposition to certain diseases.

The discovery suggests that researchers focusing exclusively on genes to learn what makes people different from one another have been looking in the wrong place.

Butterflies are emerging over 10 days earlier in Spring than they did 65 years ago, and anthropogenic global warming is probably at fault, according to a study in Biology Letters.  

The study found that mean emergence date for adults of the Common Brown butterfly (Heteronympha merope) has shifted 1.6 days earlier per decade in Melbourne, Australia. Early emergence is causally linked with a simultaneous increase in air temperatures around Melbourne of approximately 0.14°C per decade, and this warming is known to be human-induced.

Dogs likely originated in the Middle East, according to a new genetic analysis published this week in Nature.

The study reports genetic data from more than 900 dogs from 85 breeds and more than 200 wild gray wolves (the ancestor of domestic dogs) worldwide, including populations from North America, Europe, the Middle East and East Asia. Researchers used molecular genetic techniques to analyze more than 48,000 genetic markers.

The data include samples from Israel, Saudi Arabia and Iran — but they have not pinpointed a specific location in the Middle East where dogs originated.

A 3,000-year record from 52 of the world's oldest Sequoia trees shows that California's western Sierra Nevada was drought-ridden and often on fire from 800 to 1300, according to a new study published in Fire Ecology.

During those 500 years, known as the Medieval Warm Period, extensive fires burned through parts of the Giant Forest at intervals of about 3 to 10 years. Any individual tree was probably in a fire about every 10 to 15 years.

Knowing how giant sequoia trees responded to a 500-year warm spell in the past is important, the authors say, because climate change will probably subject the trees to such a warm, dry environment again.

Bees see the world almost five times faster than humans, giving them the fastest color vision of all animals, according to new research appearing in the Journal of Neuroscience.

The ability to see at high speed is common in fast-flying insects; allowing them to escape predators and catch their mates mid-air. However, until now it wasn't known whether the bees' full colour vision was able to keep up with their high speed flight. This research sheds new light on the matter; suggesting that although slower, it is also much faster than human vision.