Origin of Evolution

Evolution seems to be the most scientific answer to our origins. Is it?
A couple of pertinent questions arise.
What causes evolution?
What is motivating it?
Among plants tasty fruits, fragrant and pretty flowers, appropriate levels of lightness, hardness and other attributes of seeds, (to name a few) have been found as expedients for seamless continuation of species. Isn't it right to assume that Mother Nature, who has instituted these amenities for flora, would certainly have established an analogous measure for fauna too? Concede, we have around us the superfluities men and women choose to adorn themselves, be in the form of make-up, fragrance, ornaments, dress or other accompaniments which can be thought of as expedients similar to the ones seen among plants. But that doesn't stop, one question form popping up; would nature have left such an important feature of evolution to the vagaries of individual choice?
A close examination into the life and style of male and animals show  that each and every instance of sexual union shows the way to a disagreeable finale, in which, the male always is at the receiving end. That is to say, the female becomes disgust personified by the end of  every such event. Moreover, the expression of such revulsion can be readily observed in the post mating behavior of females, many of them acute expressions of distaste. What could be the rationale behind the subjecting the animal kingdom to such a predicament if not for meeting an essential need of life.  It seems the immediate thought of our forefathers was of the calamity waiting for humans (males) if something is not done to prevent the females from expressing their displeasure after each and every instance of sexual union and did take appropriate actions to preclude this. All that we celebrate today as unique human qualities are in fact leftover  of those 'appropriate actions'. That certainly has made the human (males') life more comfortable, but the search for the rationale escaped them.
This book is trying to find that.