I've not seen anyone mention,
The Evolved Radio and its Implications for Modelling the Evolution of Novel Sensors, but maybe I missed it.
quote:
We have described an unconstrained, intrinsic HE {hardware evolution} experiment that resulted in the construction of a novel radio
wave sensor. The EM is the second ever experimental system
to construct novel sensors, unconstrained by prespecified
sensor/environment channels. Like Pask’s ear, the evolved radio determined the nature of its relation to, and knowledge
of, the world. Both of these devices are epistemically
autonomous: they are not restricted to experimenter specified
information channels...
We argue that devices such as this are useful for
highlighting the practical impossibility of simulating the
evolution of novel sensors: programming a simulation
necessarily involves prespecifying the possible
sensor/environment interactions. Novel sensors are
constructed when a device, rather than an experimenter,
determines which of the infinite number of environmental
perturbations act as useful stimuli. Unconstrained, intrinsic
HE has provided a concrete example of such a device and is
potentially a powerful approach to designing robot sensors as
it enables circuits to exploit the rich dynamics of
semiconductor physics and thereby explore regions of design
space that are inaccessible to the conventional engineering
approach.
Given sufficient freedom, and appropriate selection criteria: sensors may be an inevitable outcome with regards to evolved systems. For what its worth the evolved radio was too complex to be understood by humans and it was irreducibly complex. Yet it was not designed by any human.
quote:
It has proved difficult to clarify exactly how these circuits
work. Probing a typical one with an oscilloscope has shown
that it does not use beat frequencies to achieve the target
frequency. If the transistors are swapped for nominally
identical ones, then the output frequency changes by as much
as 30%
It should be pointed out, in case it wasn't clear, the experimenters were not trying to create a radio. It just sort of happened.
quote:
The evolutionary process
had taken advantage of the fact that the fitness function
rewarded amplifiers, even if the output signal was noise. It
seems that some circuits had amplified radio signals present
in the air that were stable enough over the 2 ms sampling
period to give good fitness scores. These signals were
generated by nearby PCs in the laboratory where the
experiments took place.
In order to pick up radio signals the circuits need an aerial
and an extremely high input impedance. This was achieved
by {evolvable motherboard} using as an input the printed circuit board tracks on the
EM connected to an open programmable switch whose
impedance is at least 100 MΩ. The high impedance was
confirmed by an electrometer behaviour observed in many of
the non-oscillating circuits...The evolutionary process
had utilised not only the EM’s transistors, but also the
analogue switches and the printed circuit to which they were
connected.
The evolvable motherboards evolved to be able to sense nearby computers. No brain required.
Edited by Modulous, : corrected Ω from W
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