These are the photographs of a strange bug I came across during my stay in Manipur state of North East India. The dorsal view of the insect resembles a human face.  This semblance to human face doesn't appear to be by chance. What evolutionary advantage could have favored such an adaptation.

is there a reason we have a separate bone to articulate the knee (patella), yet elbow articulation is achieved through an extension of an existing bone (olecranon process)? did we evolve them seperately to suit our activities, and do other primates share a similar skeletal anatomy, or have they different structures to suit their movement patterns? it seems to me that the structure of the 2 joints are similar enough ( 1 strong bone forming a hinge joint with 2 smaller bones which articulate about each other) yet the patella seems more susceptible to injury and dislocation. would we be better off with a solid extension of the tibia or would this have led to other problems? i am currently studying a sports injuries course, and the tutor (who obviously understands more on the subject than me by the way, yet doesn't satisfy my curiosity sufficiently) states that we need a patella because of the fine proprioceptive requirements of the leg, but if anything i would have placed (if i were creating humans from scratch) a strongly attatched bony process for the knee joint for weight bearing, and a finely controlled sesamoid bone joint in the elbow for finer hand dexterity. what am i missing?

It's claimed by some that eyes are diffraction limited at the small end. Are there any upper limits on the size of animal eyes?

Giant squid aside, how do eyes scale with body size?

As a correction to this question, some argue that the (non-compound) eye might have originally evolved as a "camera obscura" with a pinhole lens; more complex lenses may have then followed. Is there any physical limit on a pinhole lens that might have (historically) limited the size of an eye?

Our smelling sensors are inside the head. Our noses are vulnerable to damage and the majority of primates and other mammals manage with relatively flat faces.

Dennis Newland, Purley, Surrey, UK

Snow makes you cold and wet, yet humans still seem to enjoy playing in it. How could this help us survive?

Evolution posits that humans and chimpanzees are descended from a common ancestor. Other animals also share common ancestors or intermediate forms. Have any of these intermediate forms survived to the present day? Or have only the final forms survived? Shouldn't every final form also be an intermediate form?

Most apes bodies are completely covered in hair with the exception of their faces; humans being the exception with only very fine hair on their bodies  while adult male humans grow thick facial hair, in particular moustaches.  I imagine heat, clothing, etc may have caused humans to lose their body hair in the course of evolution but I'm intruiged about why we gained a moustache.