In my ongoing effort to emphasize the cognitive capabilities of cells, this blog describes two examples of highly sophisticated searching behavior by very different kinds of cells. At the same time, I want to discuss the bewildering resistance of at least one conventional evolutionist to additional researchers coming in from other fields to help unravel biological phenomena. The two subjects are connected because cooperation with scientists trained in other disciplines was critical to revealing sophisticated cell search capacities in both examples.
In his "Sandwalk" blog last year, Larry Moran attempted to make fun of my enthusiasm for physicists bringing their skills and insights into biology:
"Meanwhile, I welcome all those physicists who know nothing about evolution, protein structure, genetics, physiology, metabolism and ecology. That's just what we need in the biological sciences to go along with all the contributions made by equally ignorant creationists."
Moran's dated sarcasm equating physicists with creationists was pointed out to me by a friend who also sent a link to a recent news story about how T cells hunt down Toxoplasma gondii parasites in infected mice.
The ScienceDaily story referred to a Nature paper published this week by a group that involved "... a unique collaboration between the laboratories of senior authors Christopher Hunter, professor and chair of the Pathobiology Department in Penn's School of Veterinary Medicine, and Andrea Liu, the Hepburn Professor of Physics in the Department of Physics and Astronomy. Penn Vet postdoctoral researcher Tajie Harris and physics graduate student Edward Banigan also played leading roles in the research."
The physicists used their analytical skills to identify the T cell search strategy as a "generalized Lévy walk" partially guided by chemokine signals. This was not something the biologists could have learned on their own.
The T-cell results are especially important because they show that single cells display a search ability that parallels one used by multicellular organisms with nervous systems. The authors write in their summary: "... CD8+ T-cell behaviour is similar to Lévy strategies reported in organisms ranging from mussels to marine predators and monkeys, and CXCL10 aids T cells in shortening the average time taken to find rare targets."
The T cell case is not isolated. An increasingly famous example of sophistication in cell migration and search behavior is the study of slime mold Physarum polycephalum amoebae migrating through mazes.
The slime mold work was done not in a biological institution but by Toshiyuki Nakagaki and his colleagues at the Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan.
Condensed matter physics statistical analysis has been central to this research, and
the slime mold solutions have proved superior to mathematically-derived search patterns. As the researchers wrote in a 2004 article:
"Statistical analysis showed that the network geometry met the multiple requirements of a smart network: short total length of tubes, close connections among all the branches (a small number of transit food-sites between any two food-sites) and tolerance of accidental disconnection of the tubes. These findings indicate that the plasmodium can achieve a better solution to the problem of network configuration than is provided by the shortest connection of Steiner's minimum."
Among the behaviours documented by Nakagki and colleagues are maze-solving to find the minimum path for access to nutrients and anticipation of periodic depletion of nutrients.
The Physarum solutions have even been applied recently to optimizing railroad traffic (reported in 2011). The use of biomimetic methods to find superior algorithms for traffic control illustrates how biology can contribute to mathematics, the physical and computational sciences.
In studying and analyzing the computational feats of living organisms, we will learn how networks that are far more sophisticated than our own operate to solve problems. We need the help of physicists and mathematicians to do that. Why would anyone serious about understanding how life really operates want to exclude them?
As I said in my book, we can expect new information science to arise from studying cells and evolution. I'm surprised that Larry Moran did not choose that prediction to ridicule. Maybe he found it too fantastical for his highly critical attention. Or perhaps he saw that goal as incompatible with his vision of evolution science, which seems to be to keep things just as they are.
Scotland opens stem cell research center and bio-medical incubator
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Berthajane Vandegrift
A Few Autistic Questions about Freud, Marx and Darwin
You are truly a puzzle to me. I assume you would like to convince others of your point of view, you seem very upset when others disagree with you. Yet, the approach you take - for example: "Intelligent Design cretinism" is almost guaranteed to push those who do not agree with you (in this case the intelligent design advocates) away from your position.
Is your penchant for nastiness so overpowering that you cannot state your points in a respectful manner, showing RESPECT for others who may disagree with you? People come to this blog with a wide variety of viewpoints. You will understandably disagree with many of these people. Can you not show this disagreement in a polite and respectful manner, without resorting to nastiness? In this regard, you are your own worst enemy - your response, far from convincing those who disagree with you, ends up convincing them that your position is not worthy of consideration. Being nasty to someone does not convince him of the truth of your position.
http://www.huffingtonpost.com/2012/06/07/earth-tipping-point-study_n_1577835.html
Among the authors include such notable biologists as paleobiologist Anthony Barnosky, ecologist James H. Brown (who was a graduate school professor of mine elsewhere) and marine ecologist/invertebrate paleobiologist Geerat J. Vermeij.
One of the co-authors, University of California, Berkeley graduate student Nicholas J. Matzke, has his own personal take on it here:
http://pandasthumb.org/archives/2012/06/predicting-a-st.html
Eventually the current "Neo-Darwinian" theory of evolution will be subsumed within another, more expansive, evolutionary theory, but that will happen only when it can't account for a substantial portion of the existing biological data, not because there are those who wish that it would "fade away".
How do "optimized" patterns allow cells to chase moving targets, respond to chemical signals, or anticipate nutrient changes they have experienced? The sensory component is essential. Once you include that, you're into the cognitive realm, however it operates.
[noncount] technical : conscious mental activities : the activities of thinking, understanding, learning, and remembering "
From Merriam Webster's online dictionary. Can cells learn and remember? Sure. Can they act upon it? Sure (but within very specific limitations). Can they understand? I don't think so, and I am yet to see evidence saying otherwise.
Can they think?
"think"
intransitive verb
1
a : to exercise the powers of judgment, conception, or inference : reason b : to have in the mind or call to mind a thought .
Also from MW. To say that they can think one must say that they exercise the powers of judgement, conception, or inference. And I don't see cells do any of that, so as far as I'm concerned, they don't think.
So they only fill two out of four needed prerequisites for cognition, and one only in a limited fashion. Hence, cells don't seem to have the elements of cognition. The sensory component is essential because without sensory input life isn't life in the first place either way, so we're back to square one on a tautologic dissertation of cell cognition.
On an entirely different subject, since you claim now to "like" the Discovery Institute as much as my friends Barbara Forrest and Ken Miller, then perhaps you might concur with Barbara's assessment of one of the Discovery Institute's "favorite" philosophers, one Bradley Monton:
http://lasciencecoalition.org/2012/05/31/monton-didnt-get-the-memo/
"[T]he T cell search strategy [is characterized] as a "generalized Lévy walk" partially guided by chemokine signals".
When monkeys engage in this strategy we have no problem identifying the mechanism which makes it possible: they have both a brain and a nervous system; cognition on their part is easily explained. Since T cells have neither we may be inclined to argue that for them cognition is impossible. Their observed behavior, although easily explained if they were capable of cognition, must instead be explained by mechanisms known to be compatible with their limitations, even if the explanations require us to 'bend' things a bit.
This situation is analogous to what physicists faced about a century ago. The famous "two slit experiment" showed that electrons and photons were in fact doing things which were clearly impossible: they were being in two separate places at the same time (among other things). This 'impossible behavior' was explained by expanding our understanding of physics to include what is now known as quantum mechanics.
Perhaps an analogous expansion of our understanding of 'life' will make it possible to explain 'cognition' which is now clearly seen in individual cells. Science advances not by forcing 'new wine' into 'old wine skins' but by discovering 'new wine skins' which comfortable accommodate the 'new wine'.
About 30 years ago, Nature magazine posted a letter comparing Darwinian evolution to the Law of Gravity. I answered and asked if that was Newton's Law or Einstein's Law. Science always changes, whether it's biology or physics.
In both cases, it's turtles all the way down, and we have to live with the realization that we'll never get to the bottom. That seems hard for some people to accept. So they fantasize certainty. That kind of belief structure has a fascinating similarity to religion.
For Newton, space was an absolute boundless 3 dimensional entity. Time was also absolute and was totally independent of space. Gravity was an unexplained force which acted instantaneous across unlimited distances
Einstein showed that neither space nor time exist as separate entities but rather are aspects of a 4 dimensional space-time, an entity that is not absolute but can be 'warped'. Gravity is no longer a force acting at distance but a local action between mass and warped space-time.
The paradigm shift brought about by the 'change' in our understanding of gravity is truly mind boggling. Will the theory of evolution undergo a similar paradigm shift in the future?