As applied to Species;
Take for example the ladybird beetle a rather common insect considered by most to be cute. The ladybug (as it is incorrectly known) is probably not even aware of gravity, and not because it did not do well in physics, but because in the life of a ladybug gravity is a rather insignificant force. On a rleativistic plane it would be as important as friction is to the average person while walking. They would only become aware of a lack or increase in friction if confronted with a patch of ice or an extremely slippery surface or happened to walk into a rather deep, muddy area, both cases would result in a very significant change in their walking pattern, caused by a change in the force of frictiuon between their feet and the ground. The ladybug on the other hand is very aware of friction when walking but barely affected by gravity, as can be readily seen when the ladybug is walking on the ceiling or up a wall. Two procedures that become very difficult for us because the forces of gravity far overcome the forces of friction necessary to keep us on the wall or ceiling. If we could decrease our mass to that of a fly and increase the surface area of our feet and hands to that of the flies we would discover the act of walking on a wall or ceiling to become difficult only in overcoming the friction needed to hold our feet in place. So you see, relativity is important when trying to understand the forces that are important in the life of a fly and a person but not the same relativistic ideas as proposed by Mr. Einstein !
This same idea holds true for the Bacterium, who is very aware of Brownian Movement (the movement of very small particles due to the constant bombardment of molecules such as air) and friction but again as aware of gravity as we are of Brownian Movement Although we might not consider Browniam Movement a force of the same magnitude as gravity, the Bacterium would!!
Again we see that the idea of life is not only dependant upon the more common environmental conditions; air, water, food, protection, etc.(not to say that even these are not cast in stone), but upon forces that change in their very significance from one type of organism to another. In other words the idea that life cannot be understood unless we have a grasp on every factor that affects a particular organism. and that these factors transcend the simple into the realm of relativity, albeit in a Biological sense as well as a physical sense.