Anatomical variations and evolution: re-evaluating their importance for surgeons.

For several decades, anatomists and biological anthropologists have made an intensive study in anatomical variations in ancestral and living humans. While many anatomical variants do not require clinical attention, some may present diagnostic problems or augur adverse symptoms. It is only in the last few decades that a plausible argument has been made that anatomical changes in human individuals and lineages demonstrate ongoing microevolution. Since the mid-19th century, there has been a reduction in differential mortality. Increased variation of heritable traits is a consequential outcome of relaxation of natural selection. Consequently, this has contributed to various anatomical variations in musculo-skeletal anatomy, vascular anatomy as well as congenital disorders such as spina bifida occulta. The authors argue that surgeons and anatomists should improve their knowledge of evolution and its continuing influence on human morphology. Simply repeating the old mantra that anatomical variations are important because knowledge of them minimizes surgical complications, albeit important, is inadequate.