Wise
Oysters, Galloping Sea Stars, and More: Biological Marvels Keep Coming
January
28, 2020, 12:34 PM
Strong theories in science
require fewer auxiliary hypotheses when new discoveries come to light. Design
advocates can gain confidence when discoveries continue to illustrate the core
principles of intelligent design, like irreducible complexity, meaningful
information, and hierarchical design, while undermining the blind, gradualistic
principles of Darwinian evolution. Here are some recent illustrations.
“Pearls of Wisdom”
That’s the headline on news from
the Okinawa Institute of Science and Technology,
where the only thing said about evolution is that “From a genetic and
evolutionary perspective, scientists have known little about
the source of these pearls” in the Japanese pearl oyster, Pinctada
fucata. By implication, don’t look for pearls of wisdom from evolutionary
theory. The research published in Evolutionary Applications only
concerns genetic variations within the species and the
geographic distributions of isolated populations. If it helps conserve these
oysters with their magnificent mother-of-pearl nacre — the envy of materials scientists —
well, it’s wise to keep jewelry makers in business. Design scores as evolution
fumbles.
Flight Feathers
Another level of design has been
uncovered in bird feathers. In Science Magazine,
Matloff et al. discuss “How flight feathers stick together to
form a continuous morphing wing.” Pigeon and dove wing feathers spread out from
their folded position into beautiful fans, as most people know. But how do
birds prevent gaps from opening up between individual wing feathers? The team
found a combination of factors at work.
Birds
can dynamically alter the shape of their wings during flight, although how this is
accomplished is poorly understood. Matloff et al. found that two
mechanisms control the movement of the individual feathers. Whenever
the skeleton moves, the feathers are redistributed passively
through compliance of the elastic connective tissue at the feather base. To
prevent the feathers from spreading too far apart, hook-shaped microstructures on
adjacent feathers form a directional fastener that locks
adjacent feathers.
Notice that the muscles, bones,
and connective tissue inside the skin work in synergy with the exterior hooks
on the wings. Using a robot mimic, the team found that (1) the muscles for each
feather keep the angle just right to spread them into a fan arrangement, and
(2) the barbules snap together quickly to create a lightweight, flexible
surface without breaks. The barbules can quickly detach like the hook-and-loop
materials we are all familiar with.
This clarifies
the function of the thousands of fastening barbules on the
underlapping flight feathers; they lock probabilistically with the tens
to hundreds of hooked rami of the overlapping flight feather and form
a feather-separation end stop. The emergent properties of the interfeather
fastener are not only probabilistic like bur fruit hooks, which inspired
Velcro, but also highly directional like gecko feet setae
— a combination that has not been observed before.
Rapid opening and closing of
wings makes a little bit of noise a bit like Velcro does, explaining the din
when a flock of geese takes off. Interestingly, the researchers found that
night flyers like owls, which need silent wings as they hunt, “lack the lobate
cilia and hooked rami in regions of feather overlap and instead have
modified barbules with elongated, thin, velvety pennualue” that
produce relatively little noise. Otherwise, this amazing complex mechanism
works at scales all the way from a tiny 40-gram Cassin’s hummingbird to the
9000-gram California condor. What’s an evolutionist going to say about this
ingenious mechanism? Once upon a time, a dinosaur leaped out of a tree and…
died.
Distributed Running
Sea stars, seen in time-lapse
videos, appear to “run” across the sea floor, bouncing as they go:
Scientists at the University of Southern California wondered
how the echinoderms do it without a brain or centralized nervous system. The
undersides of sea stars are composed of hundreds of “tube feet” which can move
autonomously. How do they engage in coordinated motion?
The
answer, from researchers at the USC Viterbi School of Engineering, was recently
published in the Journal of the Royal Society Interface: sea
star[s] couple a global directionality command from a “dominant arm” with individual,
localized responses to stimuli to achieve coordinated locomotion. In
other words, once the sea star provides an instruction on which way to
move, the individual feet figure out how to achieve this on their own, without
further communication.
That would be a cool strategy for
robots, the engineers figure. In fact, they built a model based on sea star
motion, and show both the animal and robot movement side by side in the video
above. No other animal movement seems to use this strategy.
“In the case of the sea star, the
nervous system seems to rely on the physics of the interaction between the body
and the environment to control locomotion. All of the tube feet are attached
structurally to the sea star and thus, to each other.”
In
this way, there is a mechanism for “information” to be communicated
mechanically between tube feet.
Even though one of the team
members was a “professor of ecology and evolutionary biology,” he seemed to
rely more on the engineers than on Darwin.
Understanding how a distributed
nervous system, like that of a sea star, achieves complex,
coordinated motions could lead to advancements in areas such as robotics.
In robotics systems, it is relatively straightforward to program a robot to
perform repetitive tasks. However, in more complex situations where
customization is required, robots face difficulties. How can robots
be engineered to apply the same benefits to a more complex problem or
environment?
The
answer might lie in the sea star model, [Eva] Kanso said. “Using
the example of a sea star, we can design controllers
so that learning can happen hierarchically. There is a
decentralized component for both decision-making and for communicating to
a global authority. This could be useful for designing control algorithms for
systems with multiple actuators, where we are delegating a lot of the control
to the physics of the system — mechanical coupling — versus the input or
intervention of a central controller.”
Once again, the search to
understand a design in nature propels further research that can aid in the
design of products for human flourishing.
Quickies:
Grasshoppers don’t faint when they leap.
Why? Arizona State wants to know how the
insects keep their heads while taking off and landing in all kinds of different
orientations. Gravity should be making the blood slosh around, causing
dizziness and disorientation, but it doesn’t. Apparently it has something to do
with the distribution of air sacs that automatically adjust to gravity, keeping
the hemolymph (insect blood) from rapidly moving about in the head and body.
“Thus, similar to vertebrates, grasshoppers have mechanisms to
adjust to gravitational effects on their blood,” they say.
Cows know more than their blank
stares indicate. Articles from Fox News and the New York Post had fun with a “shocking
study” about “cowmoooonication” published in Nature’s open-access
journal Scientific Reports. Experiments with 13
Holstein heifers seem to indicate that they all know each other’s names, and
can learn where food is located, and more, from each other’s “individual moos.”
They regularly share “cues in certain situations and express different
emotions, including excitement, arousal, engagement and distress.” Other
scientists are praising young researcher Ali Green, whose 333 recordings and
voice analysis studies of moooosic is like “building a Google translate for
cows.”
Design appears everywhere
scientists look when they take their Darwin glasses off. For quality research
that actually does some good for people, join the Uprising.
Photo
credit: Japanese pearl oyster, Pinctada fuc