According to a recent article published November 2010 in BioScience, Darwinian evolution faces “problems” that are “huge” when trying to account for the origin of biomimicry in and camouflage [http://legacy.ucpress.net/doi/pdf/10.1525/bio.2010.60.10.12]. The article reads,
The balance of Dazzled and Deceived focuses on the genetics and development of mimetic patterns, as revealed mostly through work with butterflies. The problems here are huge for evolutionary biologists. How does natural selection build a complex organism with all its integrated parts through fixation of random mutations? Butterfly mimicry has been a classic arena in which to tackle this problem precisely because the gambit is so obvious: To be a good mimic of another species requires many pattern elements of bars, lines, colors, and even wing shapes to change at once. Moreover, how can this process produce females that are perfect mimics and males that look nothing of the sort within a single species?
For example, this Leaf Mantis Butterfly mimics a leaf with stunning realism:
And, entirely different species of butterfly appear to look identical. The Monarch butterfly has a poisonous double that is of an entirely different genus of butterflies.
Casey Luskin has more to say on this subject here, http://www.evolutionnews.org/2011/02/butterfly_mimicry_a_huge_probl044101.html
Here, a Cuttlefish (Sepia officinalis) perfectly blends in with sand nearly undetectable.