Whether it is in the observation of the natural world, or in the discovery of phenomena facilitated by our relatively recent scientific progress, the presence of repeating patterns in different environments and scales has long fascinated us. The dominance of certain patterns in nature can be explained the process of sexual and natural selection and hence we are drawn to these patterns, as they confer strength and dictate survival and prosperity.
Arguably the most common pattern demonstrated in nature is symmetry. This pattern in its various forms can be found throughout nature and is exhibited by both living and non-living things in a great range of scales. While the symmetry found in non-living things can be explained by the mathematical principles that govern their formation, such as the cuboid crystal habit of pyrite and the six-fold symmetry of snowflakes.
There are multiple types of symmetry that can be exhibited by true crystals. This pyrite crystal exhibits a cuboid crystal habit. 
Snowflakes, though different from one another, all display six-fold symmetry
What makes the prevalence of symmetry interesting is how living things display the same patterns, using different mechanisms. Most common in the natural world is bilateral symmetry, in which there is symmetry over one plane, creating a ‘mirror image’. The ubiquity of bilateral symmetry can be explained by a pattern of events during the growth of an organism. When an organism moves in one direction, it automatically has a front end, which encounters the environment first. Hence, the sensory organs are clustered here and the organism develops a ‘head’. Given the generation of a front/back difference and a dorsal/ventral difference, mediated by the effects of gravity, left and right are unavoidably distinguished. It is this motion in a given direction that also leads to the formation of symmetry over the sagittal plane, as this gives rise to, for example, the equal distribution of legs on each side of an organism.
The advantage of the early symmetrical organisms is clear to see; equal distribution of limbs leads to more successful movement in a given direction. Additionally, organisms of the phylum Echinodermata, which includes starfish and sea urchins, have developed their characteristic five-fold symmetry to be able to detect both nutrients and signs of danger from all directions. The same principle can largely be applied when explaining the prevalence of symmetry elsewhere in the natural world: objects that demonstrate symmetry are far stronger than those that don’t, hence objects like cuboid crystals and snowflakes tend to form these structures.
The prevalence of this pattern is almost to be expected, given the fact that the examples discussed are largely the same in terms of size and nature, when you take the diversity of the whole universe into account. What is surprising, then, is when similar patterns are found in systems that are seemingly incomparable in nature and size. Take, for example, the largest thing conceivable – the universe – and compare it’s theorised ‘shape’ with that of something far more tangible – the neurones that make up our central nervous system. The results are astounding:
Now that these repeating patterns are being recognised, we are beginning to identify patterns in nature that could be capitalised upon for our benefit. Recently, specialists in unconventional computing at the University of the West of England Adam Adamatzky and Jeff Jones, performed experiments involving the slime mold Physarum polycephalum, which grows tendrils to seek out sources of food. They attempted to faithfully recreate a road map of the United States, with the mold starting in New York and food placed in the location of the major cities. The result was impressive:
The similar pattern created shows that the mold acts in the same way as the organisations that plan the roads around the country. Indeed, because slime mold finds the paths that are most resilient to faults or damage, it could be used to make mobile-communication and transportation networks hardier.
So, no matter where you look, there are similar patterns spread throughout nature. Whether it is the symmetry that surrounds us in the natural world or the eerily similar structures of hugely different systems, ranging hugely in size and tangibility, the same patterns are repeated again and again. The reasons can vary – symmetry can arise due to the result of an even distribution of pressure, or as a result of the natural stages in the growth of an organism. We may in the future take a hint from the ubiquity of certain patterns in nature and use them in the development of our own systems.
