What is that which makes us so....special....!!!!.....???

Every human is proud of his/her physical or mental domination over all other creatures. But do we know all the facts about other organisms to make the statement. Actually human are somewhat special but not to the extend we think we are. I suppose we have to reconsider our very perception that only humans can think or memorize or sleep etc.

If you think that only humans had the ability to reflect on their own thoughts, technically which is called 'meta-cognition". Well, think again. A Psychological study done at University of Georgia reflects that rats also have this ability. They think; they express but it reflected that they know what they don't know. Likewise if you think that only humans can sleep, think again!!! Not just dogs but flies do also sleep, just like we do and more importantly, it's the expression of the same genes during sleep and awake hours; just as in the case of humans. Astonished….!!! If not then you should now because the research also suggests that even protozoans sleep! Good grief.
But logically, there has to be a difference, there has to be a difference in the way we memorize things; we logically think; we imagine; we create; surely there is something very special about humans. And what is that?? It's our Brain!!! It's the brain that differentiates humans from others.

Human brains weigh on average 1,300 grams; a squirrel brain weighs six grams. Some of this difference is because, as larger animals, we need more brain to run our bodies. However, the brains of our nearest relatives, the great apes, weigh only 300–500 grams, even though their body size is similar to ours

Yes!! Having said this, one can say that if brain size is the criteria then may be elephants or whales or dinosaurs who must be the most intelligent creatures on the earth. But there are a lot other factors too. Actually it's the brain and body size ration. Human sits at the top of the pile if relative brain size is considered.

This is not enough…!!! Actually we are different because of difference in the structure of brain and ite differential evolution. Magnetic resonance imaging and normalization of absolute brain sizes produced the adjacent image. Fig A shows
Three-dimensional reconstruction of a reference bonobo (pygmy chimpanzee) brain; Fig B is a reference human brain. The virtual bonobo brain has been transformed into the virtual human brain using an elastic deformation algorithm. Fig C represents the local deformation vectors which are colour-coded and projected onto the virtual human brain.

The most dramatic changes in brain shape occur in (1) the Ventro-orbital prefrontal cortex, (2) the ventral stream of the visual cortex, and (3) the hypothalamic Neuro-endocrine region.

Now let us see what is in these 3 regions which makes human very special.

• Ventro-orbital prefrontal cortex: This brain region has been implicated in planning complex cognitive behaviors, personality expression, decision making and moderating correct social behavior.
  

• Ventral stream of the visual cortex:
  The ventral stream (also known as the "what pathway") travels to the temporal lobe and is involved with object identification.

• Hypothalamic Neuro-endocrine region:
  The hypothalamus co-ordinates many hormonal and behavioral circadian rhythms, complex patterns of neuroendocrine outputs, complex homeostatic mechanisms and many important behaviors.

Well this proves that we are different not from body structure but brain. We are indeed special because evolution has selected us for decision making in prefrontal cortex, for object identification via what pathway in visual cortex and behavioral differentiation in hypothalamic region.
References:

1. Jane Bradbury, Molecular Insights into Human Brain Evolution, PLoS Biology, March 2005 Volume 3 Issue 3.
2. Karl Zilles, Hartmut Mohlberg, and Peter Pieperhoff, Research Center Jülich
3. Yang Y, Raine A (November 2009). "Prefrontal structural and functional brain imaging findings in antisocial, violent, and psychopathic individuals: a meta-analysis". Psychiatry Res 174 (2): 81–8. doi:10.1016/j.pscychresns.2009.03.012. PMID 19833485.
4. Mishkin M, Ungerleider LG. (1982). "Contribution of striate inputs to the visuospatial functions of parieto-preoccipital cortex in monkeys.". Behav Brain Res. 6 (1): 57–77. doi:10.1016/0166-4328(82)90081-X. PMID 7126325.