June 16, 2015 | David F. Coppedge

Scientific Progress Needs Design, Not Darwin

Numerous papers advancing scientific knowledge rely on design principles, not evolutionary notions.

Biologists might need to revise a hoary old quote by Dobzhansky into a new one for the 21st century: “Nothing in biology makes sense except in the light of intelligent design.” In support, here are examples coming from recent science news showing a bonanza of knowledge coming out of attention to design details in living things.

Cell Wall

The stuff of cell walls is so complex, scientists are still trying to figure it out. In “Unlocking the biofuel energy stored in plant cell walls” on PhysOrg, Cherie Winner reports on the work of plant scientist Daniel Cosgrove. He is investigating some of that complexity that, when understood, will revolutionize the energy industry. “We are expert at using the structural parts of plants to make things—wood for buildings and furniture, flax and cotton for clothing—but when it comes to using them for energy, we haven’t progressed much beyond the Neanderthal stage: We burn them.” The energy that is densely packed into plant cell walls is still waiting to be understood and imitated. What’s the payoff?

Solving the mystery of cell walls could do more than provide an alternative fuel source, says Cosgrove. Farmers could sell the crop residue they currently discard, gaining extra income with little or no additional investment. In some areas, getting rid of the leftover plant matter may be even more important than gaining income.

“Down in Brazil they grow sugar cane,” says Cosgrove. “They chop up the stalks, they extract the sugars, but then they’re left with a huge residue of cell wall material. It’s very much like cornstalks, just bulkier. They used to burn it but it created air pollution problems, so they banned burning it. So they’re left with this problem, what do you do with all this stuff?

Raising crops specifically for fuel production, already under way on an experimental basis, could become efficient enough to be profitable.

The research could even translate into a wide range of other products. “Cell walls go into all kinds of things,” he says. “It’s cotton, it’s wood, it’s fibers, and it’s used in a lot of industrial processes. Knowledge lets you improve all of that. You never know where this will be picked up by engineers who say, OK, we now see a way that we can tweak this to make a product better, different, cheaper.”

The DOE has renewed Cosgrove’s funding for “another four years,” the article says—an indication of the promise in this research. He says just wants to learn how walls are made and how they work

“We knew a whole lot more about cell walls 20 years ago!” he laughs. “We were totally misinformed. We thought we knew, and we didn’t. We keep coming upon surprises, all the time, as we learn more. The wall is a much more sophisticated structure than anyone had believed.”

Photosynthesis

Knowledge about “photosystem I (PSI) and the light-harvesting complex I (LHCI) supercomplex” continues to grow, as a new paper in Science Magazine shows. Commenting on the paper in the same issue of Science, Roberta Croce gives us just a hint of the complex physical engineering that takes place at the nanoscale in pea plants:

BM-AmazingFacts-cellPhotosystem I (PSI) is an extremely efficient solar energy converter, producing one electron for nearly every photon absorbed. This large multipigment-multiprotein complex is an essential constituent of the photosynthetic membrane of plants, algae, and cyanobacteria. The energy of the photons absorbed by the PSI pigments is transferred to chlorophylls in the reaction center, where charge separation occurs. The high chlorophyll concentration in PSI maximizes light harvesting while minimizing the cost of protein synthesis; furthermore, its absorption spectrum is broad and extends to the far-red wavelengths. PSI is very stable and only becomes photodamaged in the absence of electron acceptors. The structure of the Pisum sativum (pea) PSI at 2.8 Å resolution reported by Qin et al. on page 989 of this issue helps to explain how the pigment-protein complex achieves its remarkable performance.

The researchers do not mention evolution. Croce’s only reference to evolution is to its absence: “The core part of the complex, which contains 98 chlorophylls, has been conserved [i.e., unevolved] during evolution.” By contrast, “Qin et al.‘s structure is an excellent source of information for understanding the design rules of light harvesting,” she remarks. Yes; design rules!

Lightning round

There are too many other examples of design-focused science to explore in detail. Here are some teasers for those interested:

  1. Amoeba-inspired computing system outperforms conventional optimization methods (PhysOrg).
  2. NASA tests aircraft wing coatings that slough bug guts (PhysOrg); “the materials scientists turned to nature for inspiration—lotus leaves, to be precise—to create the right combination of chemicals and surface roughness in the test coatings.”
  3. Vegetable-based artificial muscles that can expand and contract while bending (PhysOrg). “The initial goal was to develop an engineered microstructure in artificial muscles for increasing the actuation deformation [the amount the muscle can bend or stretch when triggered],” said lead researcher Wen-Pin Shih. “One day, we found that the onion’s cell structure and its dimensions were similar to what we had been making.”
  4. Ultra-tough fiber imitates structure of spider silk (Science Daily). At Polytechnique Montréal, “a group of scientists has produced an ultra-tough polymer fiber directly inspired by spiders.
  5. Researchers analyze the structure of bird feathers to create hues without dye (Science Daily). The projects at U of Akron “are just the beginning in a growing field that seeks to improve human life by imitating the success of natural designs and methods.”
  6. Color-Changing ‘Squid Skin’ Designed in Lab (Live Science). “Now, materials scientist Aaron Fishman at the University of Bristol in England and his colleagues have designed a system that mimics how cephalopod skin works.
  7. Learning about the birds and the bees helps aid flight (PhysOrg). “Research into how birds and bees use vision in flight is guiding the design of future autopilots and unmanned aerial vehicles.”
  8. Strong teeth: Nanostructures under stress make teeth crack resistant (Science Daily). “Their results may explain why artificial tooth replacements usually do not work as well as healthy teeth do: they are simply too passive, lacking the mechanisms found in the natural tooth structures, and consequently fillings cannot sustain the stresses in the mouth as well as teeth do. ‘Our results might inspire the development of tougher ceramic structures for tooth repair or replacement,’ Zaslansky hopes.”
  9. Reducing the energy cost of human walking using an unpowered exoskeleton (Nature).  “This design was inspired by ultrasound imaging studies suggesting clutch-like behaviour of muscle fascicles to hold the spring-like Achilles tendon, the recoil of which leads to the largest burst of positive mechanical power at any joint during walking.”
  10. Soft robot tentacle can lasso an ant without harming it (New Scientist). “Existing robots inspired by animal tentacles are larger, since it can be tricky to reproduce the spiralling motion at a small scale.”
  11. Robot eyes will benefit from insect vision (Science Daily). “This bio-inspired ‘active vision’ system has been tested in virtual reality worlds composed of various natural scenes. The Adelaide team has found that it performs just as robustly as the state-of-the-art engineering target tracking algorithms, while running up to 20 times faster.
  12. Wind turbines with owl wings could silently make extra energy (New Scientist). “Moving silently through the air is not just for the birds,” Jacob Aron reports. “Wind farms inspired by the stealthy flight of owls could generate more energy without annoying those who live nearby, say researchers.”
  13. New honeycomb-inspired design delivers superior protection from impact (Science Daily).
  14. New type of gecko-like gripper created at U of Pennsylvania (Science Daily). “The problem is that it’s really hard to manufacture complex structures as well as nature.

Exceptions?

Are there any bad examples? The title of this article in The Conversation might suggest a failure: “Why we fell out of love with algorithms inspired by nature.” Alexander Brownlee and John R. Woodward at the University of Stirling are not saying, however, that biological designs are found wanting. Quite the contrary! Their complaint is about so-called “evolutionary algorithms” that supposedly “draw on the same narrative as Darwin’s theory of evolution: that of a ‘population’ of individuals competing, the fittest ‘parents’ then producing ‘offspring’ which form the next generation, so that the population becomes gradually ‘fitter’ over time.” It’s actually a form of artificial selection (see Evolution News & Views) that is design-based. But despite some remarkably effective evolutionary algorithms in multiple disciplines, it has become stale in the field of metaheuristics, they say.

All researchers have been doing is wasting time on developing new approaches that are probably little better than existing ones. And the language of each metaphor then invades the literature, distracting people from using the already sufficiently expressive terminology of mathematics and, above all, working together to find the best way forward.

So their complaint is not with natural engineering, but rather with use of evolutionary algorithms to find a one-size-fits-all approach to mathematical problem solving. Even in metaheuristics, “this doesn’t mean that nature-inspired algorithms are going to decline – not while arriving at approximate solutions to our complex modern problems is still the best that we can do,” they say. “Instead the focus is shifting towards improving our understanding of how existing approaches work and improving their scientific value.” Perhaps the best way to do that is to shift the focus of Darwinian evolution and onto intelligent design.

All these scientists are so focused on design, seeing a straight path to understanding and application, they seem oblivious to thoughts about “making sense in the light of evolution.” Darwinian evolution is like the flattened coyote on the dirt road as a thousand roadrunners race to the reward.

 

 

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