We all know chronic stress isn’t good for you. This seems to be true in all organisms. But can stress kill you? A new study says yes, if you’re a dragonfly larva at least.

Researchers from the University of Toronto investigated the effects of stress on the development and survival of dragonfly larvae, reared in the presence of a predator. These juvenile dragonflies were raised in aquaria that also contained a predator. Important is that this predator had no way to actually attack the larvae.

Neanderthals had shorter legs than their Homo sapiens contemporaries, leading many to believe that the locomotion of the former was less efficient (basically, they have to take more steps to traverse a certain distance). But a new study, performed by researchers at the John Hopkins School of Medicine, questions this notion.

What’s new in this study is that it takes the terrain into account. Whereas previous studies looked only at flat land, this one considered sloped, mountainous terrain more like the environment in which Neanderthals could be found. The colder climate they were exposed to, led to a ‘compaction’ of the Neanderthal body (less surface area, thus less loss of body heat) (see figure 1).

When the DNA sequences of Homo sapiens and Pan troglodytes were sequenced, the difference between the sequences of coding genes was smaller than expected based on the phenotypic differences between both species. If not the coding genes, then what is responsible for these dissimilarities?

(Source: godlessgeeks.com)

In the words of the authors of a new study that took a look at this question:

The evolution of the human brain is the topic of a lot of research. This shouldn’t be surprising since it is so well-developed in human beings, and, as many believe, it is one of the main traits that sets us apart from our close evolutionary relatives. The seat of consciousness, culture, science, technology, and so on, exerts a great desire upon people to understand it, and to understand how it could have evolved. In order to study this question, a new study, published in PLoS Biology, investigated the occurrence and activity of evolutionary young genes in human brain development.

The researchers, from the University of Chicago, grouped their findings into four lines of evidence:

Social networks on the internet have grown greatly in the past few years. None more than the near ubiquitous Facebook, with over 800 million active users, half of which log in on any given day. Yet, there is great variability in the size of the online social networks of individual people. Is this correlated with the real-world networks of people? Does this have a neural basis? It are exactly these questions that were investigated in a new study, published in the Proceedings of the Royal Society B.

By collecting MRI scans of 125 healthy volunteers (independently replicating the experiments in a second dataset of 40 people) and having these people fill in a questionnaire, the researchers that authored the study had a look at both aforementioned questions.