[bondserv]

For well over a century biologists have looked for evidence that variation is non-random.

Forgive me if I am being stupid. Would you consider environmental pressures that cause adaptation, random. I guess you could consider environment random, but there are patterns and balancing constraints that take it from my random category.

[js1138]

Would you consider environmental pressures that cause adaptation, random.

Give me an example where genetic variation specific to need occurs as a result of environmental pressure.