This kind of motion is simpler to transfer reliably into reality, yet is rich enough to support low-momentum locomotion. Typically, several tens of generations passed before the first movement occurred. Some examples of extreme cases of convergence, speciation, and massive extinction are shown here. Each node in the tree represents an individual and links represent parent-child relationship. Vertical axis represents generations and horizontal axis represents ancestral proximity in terms of hops along the tree necessary to get from one individual to another.
All trees originate at a common root denoting an empty robot with zero bars and actuators.
The trees were thinned and depict several hundred generations each. Two arbitrarily sampled instances of entire generations, thinned down to show only significantly different individuals, are shown below. The graphs below show how fitness of creatures progresses over the generations. Each dot is an individual being born. Second, progress rate becomes slower as the fitness becomes higher.