Non sequitur. You act as though symmetry is an unexpected characteristic, when the opposite is generally true. Symmetry is the "signature" of the physical characteristics of the system, nothing more.
Not only do I have one heart on my left side and none on the right, I have one liver on my right side and none on my left.
But apparently that doesn't make me as much a freak as I thought:
... In fact, all vertebrates are fundamentally asymmetrical. The development of a vertebrate embryo results in the heart moving slightly to the left, for example, the liver to the right, and the right lung developing three lobes and the left lung two. Behaviour can also be asymmetrical. Just as humans can be right-handed, left-footed, or have a dominant eye, monkeys can prefer to use one paw to reach for fruit and humpback whales prefer to use one flipper over another when slapping the water. Snakes can prefer to coil one way rather than the other. Why might this be?This would seem to agree with tortoise's statement that symmetry is simpler than asymmetry. Specialization tends to create asymmetry, even if the asymmetrical parts are hanging off a simpler symmetric scaffolding. Interesting.
Fishing for answers
Watching chimpanzees 'fish' for termites by pushing a twig into a termite mound, it becomes clear that some chimpanzees are right-handed, some are left-handed - and some are ambidextrous. But those that are either strongly right- or strongly left-handed get to eat a third more termites than ambidextrous ones, because by using just one hand each time, they become more practised at the task. They have specialised.The two hemispheres of the vertebrate brain have also become specialised. Areas that need to communicate rapidly and constantly with each other for common tasks are best placed nearby. So, most people have a language area on the left side of the brain, which also deals with logic and usually controls the dominant hand. The right half has its own specialised areas for understanding three-dimensional space, musical pitch and savouring smells and tastes.
Lopsided language
The placement of the language centre in the human brain has caused a lot of interest, because complex, grammatical language is one of the most obvious differences between humans and other animals. In chimpanzees, the proportions of left- and right-handers are about 50:50. However, in every human culture throughout recorded history, about 90 per cent of people are right-handed. So, was the evolution of right-handedness associated with the evolution of complex language? ...