How did we get to be top of the apex and let's face it we are. The hominid that came down from the trees was not an animal to ensue confidence. Weak, not particularly fast or poisonous, an animal to ensure a very limited hope of success. Like a fox it learned to live on its wits and be open to change. When it moved north it came into competition with a similar species that was stronger and more suited to its environment. There are different conjectures on why we are where we are but luck must have been one of them. As we progressed, more available calories through more advanced hunting techniques, using fire for protection and cooking food to make more calories available. This encouraged larger groups and better communication skills. Tools gave us augmented abilities and also weapons. Like an avalanche our aptitude pulled in more advantages and our main disadvantage of longer childhood and low birth number dependencies gave us the chance to train our young in much deeper beneficial knowledge.
It's the way that that you do it. There are up to 25,000 human and up to 330,000 genes in wheat. Elephants and whales have larger brains than us. So it appears that quality not quantity is the order of the day when it comes to intelligence. The number of connections and density of neurons are the deciding factor in increased cognitive powers. The network (the connectome) and specialisation of neurons and their supporting infrastucture give us a multi-parellel reasoning system that is unique in the living world. Most of the action of brain cells are governed by chemical reactions which includes such pervasive neurotransmitters as Glutamate. These are slow acting molecules in the world of physics. The brain's ability to do many tasks at the same time, make a decion on them and action them, counterbalances its relative tardiness. The storage of previous actions is known as Symbolic Reasoning. This allows the brain to short cicuit recognition and use previous knowledge. The acts of any perception move along the brain to be intensified and analysed. Constant feedback checks symbology to see if this 'node' has been encountered before.
Faster than a speeding train
The amount of resources spent on understanding, mending and improving us has sky rocketed. Industry has realised that we are big business and are pumping trillions of dollars [insert own currency] into this affluent world that offers not only money but real benefits to humankind and other animals. Nobody has been castigated for becoming a doctor or a nurse and rightly so. The money has gradually moved from killing us, to curing us and long may it last. What has also increased, is not only the speed of knowledge but what we thought we knew. The World Wide Web is full of claims that bounce from laughable to dangerous. So called experts pick up an unproven item to run with it to make money and fame. A classic is of course immunisation, which some claim is not a miracle but a government/enemy propoganda exercise. As a previous UK prime minister once said, 'I can give you the facts but I can't give you the brains to understand them'. It is also increasingly becoming apparent that the more we know, the less we know. All sciences are finding that things are more complex than we ever thought and theories come and go.