Travel Reference
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tually flows in one direction. Some structures or proteins evolved by organ-
isms early in their history stay with them throughout time and may play a
large role in how they and their ancestors are eventually made. My favorite
example of how historical factors affect the design of organisms comes from
the study of the octopus. Octopuses are among the smartest creatures in the
ocean (much more intelligent than fish, for example), and one wonders
why their brains did not continue to enlarge until they, like us, became
truly sentient creatures. Instead, they dwell in the nether world of semi-
consciousness. In a classic account worked out by my friend Martin Wells of
Cambridge University, it was shown that the octopus suffers the ill effects of
a choice made half a billion years earlier by its hoary cephalopod ancestor,
the first nautiloid. This creature and its ilk evolved a copper-based rather
than an iron-based blood pigment to carry oxygen. Nautilus (and hence, we
presume, the earliest nautiloids as well) is a quite stupid beast with a very
small brain. A copper-based blood pigment carries more than enough oxy-
gen to meet the needs of the nerve cells and brain of a nautilus. However,
copper cannot carry as much oxygen in blood as iron can. With the evolu-
tion of a larger cephalopod brain, oxygen availability became an issue for
the first time. Because of its large size, the poor octopus's brain is nearly al-
ways on the brink of oxygen starvation, for nerve cells above all others need
a constant supply of oxygen. The octopus cannot evolve a larger brain, be-
cause its blood supply will not support more nervous tissue. Worse yet, so
basic is the type of blood pigment that the cephalopods cannot redress this
wrong by evolving an iron-based pigment at this time. It is too late. This
wrong choice offers an example of the historical aspect of functional mor-
phology at work.
The study of form and function is currently a growth industry in sci-
ence. Although this type of study has a long history, the field has taken on a
rigorous demeanor only in the last three decades. In this interval, modern
engineering techniques have been employed in studying biological struc-
tures, and much of this new emphasis stems from Duke University, where
(among others) Professor Steven Wainright and his colleagues and students
