Paying the price for body evolution (original) (raw)

A Physiological Theory of Evolution

Courtenay Young is currently the President of the European Association for Body-Psychotherapy (EABP) and works as a counsellor & psychotherapist in the UK National Health Service in Edinburgh. This article is an expanded extract from a book entitled "Under The Skin" that he is in the process of writing about psychophysiology for body-psychotherapists and body therapists. I would like to discuss a slightly different and somewhat controversial theory of evolution, based on a number of significant aspects of our human physiology, which also helps to explain some of them. It may also be of considerable interest to Body-Psychotherapists. It is quite an important story, as well as being quite a long one, so please persevere with me through it. Given the essential genetic closeness (between about 4% and 1.3% DNA differences, depending on what bit of DNA you study) between us, and our nearest relatives the large primate chimpanzees, there must have been a relatively recent point i...

Beauty and the beast: Psychobiologic and evolutionary perspectives on body dysmorphic disorder

CNS spectrums

Body dysmorphic disorder (BDD) is characterized by preoccupation with a defect in appearance. Concepts of beauty play a particularly crucial role in humans' mental and social life, and may have specific psychobiologic and evolutionary underpinnings. In particular, there is a growing literature on the neurocircuitry underpinning the body schema, body image and facial expression processing, and aesthetic and symmetry judgments. Speculatively, disruptions in cognitive-affective processes relevant to judgements about physical beauty lead to BDD.

Certain medical problems resulting from evolutionary processes: bipedalism as an example

Humans are primates, and as such, our overall anatomy is very similar to that of other members of this biological order. Yet, there are numerous differences in certain anatomical regions of living humans when compared to our closest living relatives, the African great apes. Many of these, such as our extremely large brains compared to body size (even if all primates have relatively large brains), details in dental anatomy, and so on, appear at different times in our evolutionary past and within the tribe hominini. However, the first, and taxonomically most significant synapomorphy of the hominin clade is a change in locomotory mode, from that of a quadruped (presumably the ancestral state in last common ancestor (LCA) of humans and apes) to biped. In this paper, a brief overview is given of the most important anatomical challenges that these novel locomotory patterns required to be enegretically efficient, as seen in the comparison between living African apes and humans. Further, an overview of the fossil record, as related to the issues raised, is given. Lastly, the importance of understanding evolutionary adaptations and changes for the medical profession is discussed.

Full Body: The Importance of the Phenotype in Evolution

Artificial Life, 2008

This is a position paper on phenotype based evolution modeling. It argues that evolutionary complexity is essentially a functional kind of complexity, and for it to evolve, a full body, in other words, a dynamically defined, deeply structured and plasticity-bound phenotype is required. In approaching this subject, we ask and try to reply some of the key questions of the Call for this Special Issue, as we think several of them are interrelated. The questions we discuss and answers we propose are: -How could complexity growth be measured or operationalized in natural and artificial systems? Evolutionary complexity is functional, akin to that of machines, and to operationalize it, we need to study how organismic functions work and develop. Inspired from studies on causality, we propose the notion of 'mechanism' to be the key here. A mechanism is a simplified causal system which can carry out a function exactly because of the simplification, and a growth of functional complexity involves interconversions between the 'deep' (or unused) processes and those of the simplification. -Are the principles of natural selection, as they are currently understood, sufficient to explain the evolution of complexity? The answer is strongly negative. Natural selection (and competition) help to adapt mechanisms to carry out a task, but will not generate tasks. Hence there is a trade-off between the available tasks and mechanisms that are the solutions. We argue that 'competition aviodance' is required for new complexity to emerge beyond that limit, making it possible for evolving mechanisms to reply to new challenge. -What are the environmental constraints of complexity growth in living systems? These constraints arise from the structure of the co-evolving, ecological system of organisms, and the basic constraint comes from the niche, to which an organism belongs. We suggest that 'niche constuction' is central to the generation of new complexity and that, in turn, this can be achieved by using a plasticity of the phenotype. We derive and discuss a form of phenotype plasitcity from the interconversions between hidden (unused) and explicit (functional) factors discussed in the causality part. -What are the main hypotheses about complexity growth that can actually be tested? We hypothesize that the rich natural phenotypes that can support the above interconversions are necessary ingredients of any functional complexity growth process in natural and model systems. We review our work on the FATINT system, which incoporates these ideas in computer simulations, showing that phenotype change is a sufficient factor for achieving such functional evolution. -What language is more appropriate to speak about the evolution of complexity in living systems? FATINT is developed using Agent Based Modeling (ABM) techniques and we discuss the general relevance of this methodology for understanding and simulating the kind of phenomena discussed in this paper.

How are we made?: Even well-controlled experiments show the complexity of our traits

Evolutionary anthropology, 2015

The fact of evolution seems as well established as anything in science. However, there are many questions for which we don't yet have clear answers. That's fortunate because it allows us to have careers in evolutionary sciences, during which we can try to understand the origin and genetic basis of traits that interest us. From what is currently understood, the development and evolution of physical and even behavioral traits are genetic at their core. We should be able to design studies to explore what that basis is. An important criterion for success in genetics, as in any other science, is the ability to frame a well-posed question on which to base one's research. A well-posed question should enable focused research to yield a unique, clear answer. That's particularly difficult for questions about the evolution of complex traits because we have only fragmentary physical evidence from the past; fossils that happened to be preserved, though how representative they are we can't really say, and ancient DNA from a small number of sources. Consequently, our understanding of how traits evolved necessarily rests on historical narrative rather than on direct observation of mechanism or process. We must find indirect ways to use contemporary material to pose questions about how traits are produced and evolve. Fortunately, the same evolutionary process that generated the complex traits in our ancestors also provides connections among present-day organisms and thus suggests clever strategies we can take. GETTING AHEAD OF WELL-POSED QUESTIONS Upright posture and thumbs have long interested anthropologists, but we often like to think headfirst about ourselves. Much of what makes us different from other species, and perhaps more vain, has to do with our heads. However, understanding the genetic basis of the head, or its individual traits, has been difficult. Many genes that ostensibly are important to the evolution of the head have been identified because, when mutated, they can cause serious craniofacial disorders. Many or most mutational variation in those genes seems to be so serious that the embryo doesn't survive development. In that sense, more fine-tuned adaptive evolution doesn't seem to work by purging the truly pathologic genes, but more NOTES I welcome comments on this column: kenweiss@psu.edu. I co-author a blog on relevant topics at EcoDevoEvo.blogspot.com. We thank John Fleagle for critically reading this manuscript. The Box reports collaborative work done with co-investigators James Cheverud and Jeffrey Rogers, whose contact information is, respectively,

Evolutionary Medicine: The Ongoing Evolution of Human Physiology and Metabolism

Physiology

The field of evolutionary medicine uses evolutionary principles to understand changes in human anatomy and physiology that have occurred over time in response to environmental changes. Through this evolutionary-based approach, we can understand disease as a consequence of anatomical and physiological “trade-offs” that develop to facilitate survival and reproduction. We demonstrate how diachronic study of human anatomy and physiology is fundamental for an increased understanding of human health and disease.