Physiology and the revolution in Evolutionary Biology

Rocking the foundations of biology
A major revolution is occurring in evolutionary biology. In this video the President of the International Union of Physiological Sciences, Professor Denis Noble, explains what is happening and why it is set to change the nature of biology and of the importance of physiology to that change. The lecture was given to a general audience at a major international Congress held in Suzhou China. The implications of the change extend far beyond biology itself. This video will interest economists, business leaders, politicians and others who deal with the important social questions that have been raised by ideas in evolutionary biology ever since Darwin wrote his Origin of Species.

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The President of the VPH Institute, Denis Noble, has recently delivered a lecture to a large Congress in China with the title Physiology and Evolution. The video is available.

During the lecture Prof Noble explains that a major revolution is occurring in evolutionary biology and why it is set to change the nature of biology and of the importance of physiology to that change. For the VPH project this is potentially important news. The genome is not isolated from the influences of the development of the organism and it is also sensitive to the environment.

Denis Noble uses the insight of the 1983 Nobel Prize winner, Barbara McClintock, the discoverer of jumping genes, who said that 'the genome is an organ of the cell'. As such, modellers of the cells tissues, organs and systems of the body will in future need to include the downward causation from the organism and its environment onto the genome. These determine its activation patterns (some of which are inherited), its structure, and even its sequences. This is another grand challenge for the future of the VPH project. It may still be too early to meet that challenge just yet. We need to advance the present projects to the stage where such a grand vision could be achievable. But the existence of this challenge is itself significant. It brings physiology and the VPH project into the centre ground of biology, relevant to its conceptual foundations. Moreover, the implications of the change extend far beyond biology itself.

Watch the video: http://vph-institute.org/vph-videos/
This video will also interest economists, business leaders, politicians and others who deal with the important social questions that have been raised by ideas in evolutionary biology ever since Darwin wrote his Origin of Species. The Selfish Gene (Dawkins, 1976) had precisely such an influence, many would say to the detriment of biological science and to social and political ideas (Midgeley, 2010). Denis Noble shows that all of this is metaphorical metaphysics (Noble, 2006, 2011). It is time we dropped the misleading metaphors used widely in biology during the twentieth century.


For more information:
- Dawkins R (1976, 2006). The Selfish Gene. Oxford University Press, Oxford Midgley M (2010). The Solitary Self. Darwin and The Selfish Gene. Acumen, Durham.

- Noble D (2006). The Music of Life. Oxford University Press, Oxford.

- Noble D. (2011) Neo-Darwinism, the Modern Synthesis and selfish genes: are they of use in physiology? Journal of Physiology, 589, 1007-1015.

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The “Modern Synthesis” (Neo-Darwinism) is a mid-twentieth century gene-centric view of evolution, based on random mutations accumulating to produce gradual change through natural selection. Any role of physiological function in influencing genetic inheritance was excluded. The organism became a mere carrier of the real objects of selection: its genes. We now know that genetic change is far from random and often not gradual. Molecular genetics and genome sequencing have deconstructed this unnecessarily restrictive view of evolution in a way that reintroduces physiological function and interactions with the environment as factors influencing the speed and nature of inherited change. Acquired characteristics can be inherited, and in a few but growing number of cases that inheritance has now been shown to be robust for many generations. The twenty-first century can look forward to a new synthesis that will reintegrate physiology with evolutionary biology.

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Feb. 14, 2013 — The 18th century natural philosopher Jean-Baptiste Lamarck proposed that the necks of giraffes lengthened as a consequence of the cumulative effort, across generations, to reach leaves just out of their grasp. This view of evolution was largely abandoned with the advent of modern genetic theories to explain the transmission of most important traits and many medical illnesses across generations.

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However, there has long been the impression that major life events, like psychological traumas, not only have effects on individuals who directly experience these events, but also have effects on their children. For example, cross-generational effects have been well-documented in the children of Nazi death camp survivors. Similar issues have been reported in the context of mood disorders and addiction. Until recently, these trans-generational effects were attributed to changes in the way that parents treated their children or the child's reaction to learning about the parent's history.

In the most recent issue of Biological Psychiatry, Swiss researchers from the University of Zurich and Swiss Federal Institute of Technology, led by Dr. Isabelle Mansuy, discuss how the emergence of the field of epigenetics has introduced a new component to this discussion -- the trans-generational transmission of changes in the regulation of gene expression.

"The question of the inheritance of acquired traits has puzzled biologists and clinicians for decades. Although it has been consistently observed as early as in the 18th century, the time has now come that sufficiently strong and convincing evidence has accumulated to firmly accept it," said Mansuy.

The genetic transmission of traits reflects alterations in genetic structure, i.e., the base pairs that form DNA. Epigenetics, on the other hand, involves cellular processes that do not alter the structure of DNA. Instead, epigenetic mechanisms, including the methylation of DNA or of specific residues on histone "supporter" proteins, influence the extent to which individual genes are converted into messenger RNA. These changes can occur in any cell of the body, but when they occur in the germ cells (sperm or eggs) the changes may be passed to the next generation.

The changes in DNA structure are random events that acquire functional significance in the context of Darwin's "natural selection" process. In contrast, the epigenetic reactions to specific environments are designed to enable that organism to cope with that context. When these traits are passed to the next generation, it is as if the newborn arrives prepared for that specific environment. Problems arise when the epigenetic processes give rise to traits that are not adaptive for the offspring, such as heightened stress reactivity, or when the environment has changed.

"This is a remarkable story with far-reaching implications," commented Dr. John Krystal, Editor of Biological Psychiatry. "There is a suspicion that epigenetic processes may be reversed more easily than genetic traits, exemplified by the development of HDAC inhibitors. This is a rapidly evolving research area that has captured a great deal of attention."

The article is "Transgenerational Epigenetic Effects on Brain Functions" by Johannes Bohacek, Katharina Gapp, Bechara J. Saab, and Isabelle M. Mansuy. The article appears in Biological Psychiatry, Volume 73, Issue 4 (February 15, 2013), published by Elsevier.

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