Open Questions: Thinking, Reasoning, and Logic

Questions:

How did functions like logic & reasoning evolve? What adaptive function did they serve? What were the selective pressures?
Are logic & reasoning merely by-products of other brain capabilities?
How are concepts and categories, generalization & specialization implemented? How is the notion of "similarity" implemented?
How are rules of formal logic implemented (logical operations, rules of quantification)?
How is symbolic processing implemented? Are "symbols" represented and manipulated in the brain, and if so how?
How did mathematical capabilities (counting, shape recognition, judgment of magnitude, etc.) originate & how are they implemented?

Tim van Gelder Research Publications: Many of van Gelder's publications deal with the philosophy of thinking and reasoning.
The Laboratory for Complex Thinking & Scientific Reasoning: At McGill University. "The main focus of research conducted in this laboratory is to uncover the thought processes underlying complex thinking and reasoning, especially scientific reasoning." Laboratory director is Kevin Dunbar.
What Are Numbers, Really? A Cerebral Basis For Number Sense: Article by Stanislas Dehaene, a cognitive neuropsychologist who has studied the "number sense". The question is what could be an evolutionary basis for counting and other mathematical abilities.
Jef Raskin's Effectiveness of Mathematics: An essay propounding the view that the human mind has evolved to operate (partially) in accord with logical principles, which entails it will develop mathematics in such a way as to be able to describe natural phenomena.