Co-Evolution – Where the interactions of 2 species affects the evolution of both
The cog revolution (co-evolution) of one cog affects the revolution of another cog.
Springbok and cheetahs have co-evolved in a speed arms race. As the springbok evolved to run faster, only the fastest cheetahs were able to catch and eat them. This drove the evolution of the cheetah so only the fastest cheetahs could survive and reproduce, which in turn meant that the slower springbok were less likely to survive and reproduce. Both species have co-evolved over time to be able to run as fast as possible.
Clown fish and sea anemones have co-evolved in such a way that the anemone has venomous tentacles, while the clown fish has evolved a mucus coating to its scales that renders it immune to the venom. The clown fish keeps the anemone clean of parasites by eating them while the anemone provides protection to the clownfish against predators with its venomous tentacle.