In human beings, it is very difficult to discern what is learned and what is innate in our behaviour. Despite this, the rejection most human adults feel from snakes might be an instinct inherited from our ancestors.
When a large quantity of water is observed, as happens in the sea, we notice a blue color that can vary depending on the mass of water we are observing. Professor Inmaculada Pascual Villalobos explains why.
There are numerous causes for eye redness, and many of them are not serious. Begoña Domenech Amigot, professor of the Department of Optics, Pharmacology, and Anatomy of the University of Alacant, explains.