At some point everyone has heard the question: "Which came first, the chicken or the egg.".  What is surprising about this question is that it can still produce any debate.

It is surprisingly obvious yet one wonders what has contributed to its longevity and its countinued appearance in various arguments.

Why obvious?  Well, let's consider the premises.  Unless one is predisposed to believing that animals simply appear, then we must reject the premise that a chicken can exist as a fully formed adult without any previous existence.  As a result, the only element left to examine is the egg.  Yet, an egg doesn't spring into existence fully formed either.

Male and female blue tits look a lot alike to us but in the UV-range, visible to birds, the male is much more colorful.

The term 'living fossil' is a topic for argument among scientists because it appears to suggest that some organisms have stopped evolving. Like 'missing link' or 'God particle' the concern is the colloquial meaning has overtaken the science one.

A team of scientists has uncovered how some sea snakes have developed 'shrunken heads' - literally smaller physical features than their related species.

A large head would seem to be a welcome trait for sea snakes, which typically have to swallow large spiny fish. However, there are some circumstances where it wouldn't be very useful: sea snakes that feed by probing their front ends into narrow, sand eel burrows have evolved comically small heads. 

Who says you can't go home again?  Not evolutionary biology. Well, sort of. There is a supposition with the proper name of "Dollo's law" which states that evolution is unidirectional and irreversible and once an organism has evolved specialized traits, it can't return to the lifestyle of its ancestors. It hasn't really caught on.

The  divergent lineage of the oldest known genetic branch of the human Y chromosome, the hereditary factor determining male sex, has been pushed back in time.

The new divergent lineage, found in an individual who submitted his DNA to Family Tree DNA, a company specializing in DNA analysis to trace family roots, branched from the Y chromosome tree before the first appearance of anatomically modern humans in the fossil record.

A new paper says that flocks of birds, schools of fish, and groups of any other living organisms might have a mathematical function in common - body sizes are distributed according to the same mathematical expression, where the only unknown is the average size of the species in an ecosystem. 

Researchers usingt the Green Bank Telescope (GBT) in West Virginia say they have discovered an important pair of prebiotic molecules in interstellar space. The discoveries indicate that some basic chemicals that are key steps on the way to life may have formed on dusty ice grains floating between the stars.

A year or so back Carl Zimmer asked the science world if life could be defined in three words.
I don’t think he would have been too concerned if the answer was in four or five or six words, the point of his question, I believe, was that for a definition of life to be useful, it has to be concise, and therefore, simple, understandable.

In many animals, the brain is located in a specific structure like the head, along with sensory organs and often together with the mouth.

However, there are distantly related animals which have a nervous system but no brain, like sea anemones and corals.

In a new paper, the sea anemone Nematostella vectensis was used to find out if one of the ends of the sea anemone corresponds to the head of higher animals. To do this the researchers studied the function of genes that control head development in higher animals during the embryonic development of the starlet sea anemone.