Figure – Evolutionary lego cranes and bridges. Check here for a small animation as well as a long mpeg video.

These, I believe, will be the solution for the first floating Europe-Africa bridge preliminary project (linking the Portuguese-Spanish border between Faro and Huelva, ending near Tanger – Morocco, spanning the entire strait of Gibraltar), or for many of them coming in the near future, in case they need to robustly and adaptively join further long distances:

[…] Creating artificial life forms through evolutionary robotics faces a “chicken and egg” problem: Learning to control a complex body is dominated by inductive biases specific to its sensors and effectors, while building a body which is controllable is conditioned on the pre-existence of a brain. The idea of co-evolution of bodies and brains is becoming popular, but little work has been done in evolution of physical structure because of the lack of a general framework for doing it. Evolution of creatures in simulation has been constrained by the “reality gap” which implies that resultant objects are not buildable. The work we present takes a step in the problem of body evolution by applying evolutionary techniques to the design of structures assembled out of parts. Evolution takes place in a simulator we designed, which computes forces and stresses and predicts failure for 2-dimensional Lego structures. The final printout of our program is a schematic assembly, which can then be built physically. We demonstrate its functionality in several different evolved organisms […]. in, Computer Evolution of Buildable Objects, Pablo Funes and Jordan Pollack, 1997.