What Evolves

When we ask what evolves we come to one of those subjects where the contemplative’s unique experiential insight trumps a more academic approach. The contemplative does not propose new terms; the difference is in how the meditative states uncover how it feels to relate to what those terms refer to.

DNA_StructureThe academic explanation of what evolves is, for the most part, the genetic code. Each species is carrying their signature bodily form and the DNA from which those forms have developed. The evolutionary development, evo-devo, was touched on earlier. The development process is one in which the DNA codes for how proteins will be created and those in turn become the building blocks of our body, speech and mind. The DNA holds the recipes for the liver, heart, lungs, stomach, brain, eyeballs and all the rest. The blueprint is the genetic code but the code alone is not sufficient to actualize any of the genetic features. The most recent scientific view is nuanced. It recognizes that the code specifies what to make – the form the proteins will take – yet a larger percentage of the DNA consists of genes and their regulatory elements. This equally important characteristic controls how the main production is scheduled, how the processes work together, get organized and become specialized for the task at hand. The study of evo-devo has taught us how the expression of the DNA depends on the environment it finds itself in. Ecology, the study of life in its environment, extends its reach even here. Part of the DNA environment will be the chemical coordinators created by the DNA itself. These are chemical products that are used to regulate when other DNA sequences will become active, effectively managing the production of the biological building blocks.

The subject of genetics has become commonplace in our news and movies. Most educated people have at least a basic grasp of how the amino acid base pairs form the double spiral shape of the DNA molecule. The standout feature of this molecule is its ability to duplicate itself by a process of unzipping one spiral from the other. The all-important environment the molecule finds itself in then supplies the necessary amino acids to complete the pairing process. This creates two double spirals where there was one before. Due to the strict rules governing how the amino acids pairing will take place the second one is a nearly perfect duplicate of the first. The information structure retains its integrity over generations. The luck accumulates.

What is interesting to consider is just where exactly the influence of these genetic operations end. If we can break out of our habitual knowledge of genetics and really contemplate what is being signified behind all the terms and models, the reality of living things becomes magical. Consider this very moment: this little slice of time we label now contains every currently living organism’s vibrational molecular signature in a never stopping dynamic of building, tearing down and transforming simultaneously every biochemical pathway needed to sustain life into the next moment. When we think of DNA the mind tends to isolate a double spiral model but with this thought experiment we are trying to develop an experience of just how all pervasive the magic molecule of life really is. From the grasses in the field to the tip of your nose, if it is organic matter it contains earth’s DNA: the same amino base pairs, the same replication mechanic, and the same dependency on its environment to regulate its expression is found in each and every living thing on this planet. It is the ultimate proof of a shared ancestry, a shared life.

That is one direction we can take to break out of our habitual hoh-hum understanding of genetics: sense its all pervasiveness. Another is to appreciate how the DNA since its moment of inception has never known a moment of death. Yes every vehicle which bears it is mortal through and through but as it itself propagates through the germ cells generation after generation its activities never cease.

The Cambrian explosion is a very educational illustration of just how shared our ancestory is. At that time, roughly 550 million years ago, the trick of DNA replication with slight variations seems to have met just the right conditions to explode into an amazing variety of body forms the likes of which had never been seen before or since.

Burgess500WEBIn Wonderful Life Stephen Gould discusses these Cambrian body forms, known as an animal’s phenotype, at length. It was as if the constraint around DNA’s expression was loosed and for roughly 30 million years it was anything goes at the morphology rodeo. Numerous phenotypes were tried which are no longer around. There were barrel shaped creatures that would not be out of place in H. P. Lovecraft’s Mountains of Madness. The spiny genus known as Hallucigenia hosted skinny legs with claws but, bizarrely, above each leg a rigid cone shaped spine erupted. The Opabinia was a soft body animal which hosted five eyes and a mouth that faced backwards along with a proboscis used, it is assumed, to get food into its mouth. We do not find ourselves in a world filled with descendants of the Hallucigenia or the Opabinia. These were tried but discarded.

All over the planet we are confronted with endless variety of phenotypes yet we find only so many limbs, heads, and eyes – a family of phenotypes we immediately recognize as earth life. It takes the study of something like the Cambrian explosion to appreciate just how arbitrary and contingent these details really are. The pictures of the organisms from the Cambrian era leave us with a sense of viewing alien forms; they lack the signature shapes we intuitively associate with living things on this planet. The phenotype provides another way to break through our habitual model when considering the reality of our experience in the light of genetics.

We have touched on evo-devo, the way in which the genetic code expresses itself through the development of the embryo, fetus and child. With the creation of the body the reach of the genes would seem to be at its end, but is it? Just what is this organism so wonderfully built?

When examining an organism reductive analysis can find aggregates of collections, say all the liver cells in the liver or all the brain cells in the hypothalamus. Looking the other direction, holistically putting all the parts together, we find numerous emergent properties. These are those properties that cannot be found among the parts but only exist as a characteristic of the whole. Among the most important emergent properties of living things are an organism’s behaviors. Among mammals for example, how exactly individuals of a particular species will go about foraging for food is an emergent property of its digestive system, emotional drive system acting on hunger, the homeostasis system maintaining bodily health, muscular systems controlling movement, sensory awareness guiding the movements and some form of an awareness system that can deal with the immediate feedback from the environment it encounters through the senses. This awareness needs to be able to make adjustments and adaptations to stay on track for achieving whatever feeding goal the organism has set out for itself in an ever changing environment. Now ask yourself, ultimately, where did all these systems come from? You will find their roots in the genetic code.

The full blown evolutionary view sees an animal’s many behaviors – and the internal experiences that generate them – and asses them all as an extended phenotype. The beaver’s dam is as much a part of the beaver DNA as is the beaver’s tail, to use the example from The Extended Phenotype where Richard Dawkins first introduced the idea. Everything we call instinctual behavior falls easily into the definition of the extended phenotype. After all, sticking with the example of mammalian species, the nervous system and brain are also products of the genetic code’s evo-devo procedures. The very nexus from which behavior originates is included in the scope of the intelligence we find in the genetic code.

It is indeed interesting to consider just where exactly the influences of these genetic operations end. When we see spiders create a web it is easy to attribute the skill displayed to the magic of instinctual learning. We do not doubt that the information in the genetic code that formed the spider’s phenotype included the details needed to orchestrate the building of the web. What happens when we turn our attention to ourselves?

BrocasAreaSmallThere are organs in the mind and each one is as thoroughly under the control of the evo-devo process as are our fingers and toes. The brain’s ‘organs’ are specialized areas, modules dedicated to particular information processing tasks. Language acquisition depends on these types of specialized areas and shows many indications of being influenced by genetic control. Language, its use and understanding, is associated with the brain’s Broca area whereas written and spoken language is associated with the Wernicke area. Research has shown that human children use these brain centers to learn language. It does not matter which language children are exposed to though it does matter that the language is used to interact with the child. It is as if our brain physiology has primed us to learn language which the human social environment then supplies.

Research has also shown that there is an optimal time for this exposure to occur if the child is going to become fluent in language use. This period of heightened language acquisition ends around adolescence. If a child has not been properly exposed to an environment conducive to learning language by that time, that individual will never be able to become as competent in the use of language as a native speaker. Developmental psychologists have discovered other critical periods where proper environmental inputs are required if the individual is to develop into a healthy adult. All these details are features of an ongoing evo-devo process: careful scheduling of events and adjusting exactly how biological structures will be fashioned through responding to environmental feedback.

Consider again the all-pervasive nature of the DNA molecule but now include the extended phenotype – the flower striving to be sexy for the bee, the bee’s dance communicating direction to the pollen feast and all the other activities of this buzzing, bustling world. Turn the contemplative eye within and spend some time with the dynamics of your internal world. How does learning happen? How can I think ‘my’ thoughts when I have to think them in ‘your’ language? How is it that that which seems most individual about my experience of being alive is so often one of the most collective features of being human? My fear and love, my hope and hurt, my laughter and lust all strike me as exquisitely unique. Yet, in these deepest wells of self, is there not a hint of selflessness? Is it not true that there is a sense in which, as has been mentioned before, life lives us?

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