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Sunday 10 January 2016

Biology and Maths make a second try at a closer relationship

Biology and Mathematics
Evolution News & Views May 24, 2011 6:00 AM

Perhaps mathematics can explain certain biological phenomenon.

While the chemistry and physics students suffered through semester after semester of mathematics, the biology students finished their calculus sequence and moved on. The idea was that biology does not lend itself to mathematical application in the same way chemistry and physics does, so students didn't need very much math. However, that may be old news. According to an article in New Statesman by Ian Stewart, biology may be undergoing another revolution and the result will be "biomathematics":
Maths has played a leading role in the physical sciences for centuries, but in the life sciences it was little more than a bit player, a routine tool for analysing data. However, it is moving towards centre stage, providing new understanding of the complex processes of life.
Stewart mentions at the beginning of the article that biology has undergone five great revolutions:
Invention of the microscope
Classification
Evolution
Discovery of the Gene
Discovery of the structure of DNA
He contends that mathematics may be the new, sixth revolution in biology. If we are talking about scientific revolutions in the sense that Thomas Kuhn describes them in The Structure of Scientific Revolutions, then the important point here is while the prior revolutions may have provided a greater understanding of biology they did not account for certain other observations. The next revolution provides a different framework by which that field of science operates, and opens the door for asking different kinds of questions.

What drives the research questions is the framework through which you are asking the questions. Stewart indicates that mathematics provides an apt framework for looking at the complexity of biological systems and for bringing up new research questions. He provides three interesting examples of research that was guided by questions that came out of mathematical theory. This post will look at one of them, animal markings. This particular theory had to do with work based on Alan Turing's equations and Mendelbrot's fractals.

Two scientists from Japan wanted to study the striking stripe pattern on a particular type of tropical angelfish (Pomacanthus imperator). They applied Turing's mathematical models to the patterns on the angelfish, but came up with odd results. The Turing model predicted that the angelfish's stripes move along its body. So the scientists decided to test this theory. From the article:

It seemed wildly unlikely, but when Kondo and Asai photographed specimens of the angelfish over periods of several months, they found that the stripes slowly migrated across its surface. Moreover, defects in the pattern of otherwise regular stripes, known as dislocations, broke up and re-formed exactly as Turing's equations predicted. They did this because the pigment proteins leaked from cell to cell, drifting from the fish's tail towards its head. (In animals whose stripes are fixed, this does not happen; but once the size of the animal and other factors are known, the maths can predict whether its markings will move.)
Most likely these scientists would not have considered the possibly of the angelfish's markings migrating across its body had they not used the mathematical models which pointed towards this research.

As scientists delve deeper into biological systems, they find more and more layers of complexity. Mathematics can help scientists understand the mechanisms behind the function.

Stewart mentions how DNA had changed the way we do biology. DNA, and genetics in general, turned biology into a micro-scale endeavor. Biochemistry emerged as a prominent discipline. Stewart points out that while we are able to identify the DNA sequence, we still do not understand how the genes work together:
A creature's genome is fundamental to its form and behaviour, but the information in the genome no more tells us everything about the creature than a list of components tells us how to build furniture from a flat-pack. What matters is how those components are used, the processes that they undergo in a living creature. And the best tool we possess for finding out what processes do is mathematics.
Stephen Meyer discusses how mathematics, particularly information theory, can help our understanding of DNA in chapter 4 of his book, Signature in the Cell. One of the important features to applying information theory to DNA is that DNA is mathematically similar to text (he compares it to English text) because it is not only non-compressible information, but is capable of carrying information. But it doesn't just carry information, it also conveys functional information. This leads to new research questions, particularly in origin of life research.


From a philosophical standpoint, what does it mean that these biological systems can be explained by mathematical theories (DNA and information theory, animal markings and fractals, viruses and geometry, plankton and chaos theory)? The mathematical predictability certainly implies non-randomness. It also seems to imply layers of complexity and layers of information. These layers of complexity seem to indicate something more than unguided or random processes. It seems to indicate either a front-loading of information or at least some kind of mechanism that has the end goal in mind.

Chimera: coming soon to a lab near you.

Scientists Make Part-Human Animals -- Good Idea?
Wesley J. Smith January 8, 2016 12:13 PM

Public money is being used to pay for research that create animals that are part human. From the MIT Technology Review story:

Braving a funding ban put in place by America's top health agency, some U.S. research centers are moving ahead with attempts to grow human tissue inside pigs and sheep with the goal of creating hearts, livers, or other organs needed for transplants.

The effort to incubate organs in farm animals is ethically charged because it involves adding human cells to animal embryos in ways that could blur the line between species.

This begins to cross into Dr. Moreau territory. Even the often compliant NIH is alarmed:

The agency, in a statement, said it was worried about the chance that animals' "cognitive state" could be altered if they ended up with human brain cells. The NIH action was triggered after it learned that scientists had begun such experiments with support from other funding sources, including from California's state stem-cell agency.

The human-animal mixtures are being created by injecting human stem cells into days-old animal embryos, then gestating these in female livestock. Based on interviews with three teams, two in California and one in Minnesota, MIT Technology Review estimates that about 20 pregnancies of pig-human or sheep-human chimeras have been established during the last 12 months in the U.S., though so far no scientific paper describing the work has been published, and none of the animals were brought to term.

Birthing these animals will be the next step. And who knows what health problems they could have? This is an animal welfare issue as well as bearing obviously on human exceptionalism.

Creating such chimeric beings isn't the same thing as, say, genetically altering an animal so their organs can be used for transplant, or inserting a human gene to make transgenic animals that produce a specific hormone in their milk for medicinal uses.

Hard regulatory lines need to be drawn -- which won't be easy -- and all public money limited to research that is both ethical and respectful of proper boundaries between humans and all other species.


Scientists clearly cannot be trusted to govern themselves on this matter. It is time to set well-defined limits.

Ps. Of course it's far too late to put this genie back in the bottle the lure of potential profits and fear of losing out to the competition is going to trump any appeal to virtue.