Life, Emergence and Adaptive Mutation
Life- What Is It Anyways?
I asked four people in a science forum, “What is life?” and got four different answers:
“Everything is alive.”
“To be alive is to have life...the vital ingredient to resist entropy.”
“Things that are alive make copies of themselves.”
“It depends on how you define life. A simple definition of life is that it can make copies and evolve.”
The dictionary definitions were just as varied.
Usually something to do with what distinguishes organisms from inorganic objects. Something about growth and metabolism, reproduction and adaptation to the environment.
Wikipedia defines life as:
”Any contiguous living system is called an organism.”
The free Dictionary and Merriam Webster in part had the most hilarious definition for life:
“The property or quality that distinguishes living organisms from dead.”
Definitions vary depending on the agenda of the person that is defining it. For instance, the biologist may have a difficult time defining life in order to put forth their particular theory on abiogenesis.
Definition of Life:
Compilation of New Data in Physics and Cosmology and Its Application in Support of the Theory of Abiogenesis. - by Biologist Nasif Nahle Council Leadership/Researcher Biology Cabinet Org., New Braunfels, Tx.:
“We do not have a direct definition of life, but from direct and indirect observations of the thermal state of the living structures, we can say that:
“Life is a delay of the spontaneous diffusion or dispersion of the internal energy of the biomolecules towards more potential microstates.”
Huh? The first response was “everything is alive.” Really? I suppose I shouldn’t have flushed my goldfish or buried my dog then. I’m not even going to get into that ridiculous proposition.
Even a small child understands that there is a difference between a living object such as a goldfish, and a non-living object such as a rock. However, for purposes of a scientific discussion we need to define our term precisely, unambiguously, and in a non-synonymous and non-circular manner.
Science studies objects, that which has physical presence, that which exists; object with location. Life is the set of all living objects.
So we need to define alive or living. If there are any exceptions, we need to start over with a different definition.
The second definition, “To be alive is to have life...” is not really a definition it is circular. The definition contains a variation of the term being defined. What have we learned?
What about reproduction? The very young and very old do not reproduce. Are they not alive?
So what distinguishes living objects from non-living objects? Non-living objects are different than living objects in their inability to move by themselves against gravity. This is the one criteria common to all forms of life on earth.
Non-living things move away from or towards each other due to collisions or because of a stronger gravitational pull from elsewhere.
Gravity is the attraction between two or more objects.
An object is static conceptually, but because all things are in motion on an atomic level, there is a difference between living and non-living objects in regards to motion and the definition has to account for this difference.
Hence the rational definition for a living object: a natural object which “moves by itself against gravity, and with or against the path of least resistance.”
Living things move by themselves against gravity. This movement is by way of surface to surface contact between objects just as is non-living objects.
An earthworm receives signals that there is rain above, and it moves in that direction by wiggling his body against the soil. An E-coli bacteria wiggles its flagellum against blood platelets and moves upstream. A virus just gets pushed along by the flow of blood. That ends the on-going debate about whether or not a virus is alive.
Mountains form when tectonic plates collide and volcanoes erupt. Plates collide and volcanoes erupt because of moving magma. Magma is formed because pressure creates temperatures that melt rock. Pressure is caused by gravity pulling everything towards the center of the earth. Ergo, gravity causes mountains. Mountains are not moving against gravity, but because of it!
Gases move in water in different ways related to specific gravity of the water, solubility of a particular gas, and other things such as temperature. Any motion of gas in water can be attributed to surface to surface contact between water molecules and gas molecules. Neither a gas molecule nor a water molecule moves by itself against gravity.
A monkey moves against gravity when it climbs a tree and swings on a vine. If he drops a banana, it has fallen and can't get up. If the monkey falls out of a tree, he can get up. Whether the monkey has eaten a banana or anything else in a very long time, he can still move against gravity by himself. Metabolism takes place whether he eats or not and will continue until all the body process break down and the monkey dies. There are many contributing factors to how and why a monkey moves. No one thing determines his movement alone.
The definition: “moves by itself against gravity, and with or against the path if least resistance” is the one thing common to all living objects, without exception. It is what distinguishes living objects from non-living objects - without exception.
Emergent Complexity
Neurons organizing into neural networks, water molecules forming snowflakes, and moving air creating weather patterns are all examples of the simple becoming the complex.
Telecommunication companies find the optimum location for their com towers, bees find the optimum location to put their bee hives, and prediction markets find their customers all by using swarm intelligence, a form of emergence.
Cellular automata can be used as a metaphor for the evolutionary process which can result in convergence, divergence, and extinction.
For a visual representation of how this works, spend a little time looking at cellular automata.
Apply a few simple rules and watch divergence, extinction, or convergence in action. From a successful random combination of black and white boxes, a beautiful complex pattern emerges. An unsuccessful combination, and extinction is the result. Extinction happens most of the time just like in nature.
Professor Robert Sapolsky of Stanford University gives an excellent lecture explaining the principal of emerging complexity and uses cellular automata here:
https://m.youtube.com/watch?v=o_ZuWbX-CyE
Here is an explanation of how this emerging complexity works with bees determining where to nest optimally near a food source:
A first generation bee leaves the hive, finds food, and returns randomly to the hive. It gets in the middle of the group of bees there and does a figure eight dance wiggling its tail. The angle of the tail indicates the direction to the food source, the extent to which it wiggles its tail indicates how far away to the food source, and the duration of time it wiggles its tail indicates how good the food source is.
A 2nd generation bee returns randomly and bumps into another bee doing a dance, then goes where the longer dancing bee tells it to go. We see random interaction between bees as they come and go. Longer dance increases odds of other bees bumping into them. Briefly dancing bees are less likely to bump into other bees, and all this optimizes the route to the food source. Eventually the hive moves closer to the best food source.
But when does life begin in the first place?
Living objects make the transition from simple to complex, so it is easy to make the obvious connection between simple random motion of atoms leading to life. It isn’t too difficult to imagine a progression from Atoms to elements, to molecules, to chemical compounds, to amino acids, to proteins and enzymes, to DNA & RNA, to unicellular organism, and finally to multi-cellular organisms.
With a few simple rules, and many iterations over an eternity of atoms bumping into each other, it was inevitable that complex systems such as life would arise. Intelligent life would follow eventually, and if it could have found a way to overcome data density birth rates, and overturned population, or economic pyramids, intelligent life would have found a way to cover every inhabitable surface in the universe.
The point at which something becomes a living object is when it moves on its own against gravity. At what point does this happen? At the cell level.
At what point does a tornado become a tornado? When the sky turns dark? When the wind reaches a certain speed? When the hook echo appears? Or is it when the funnel forms and rips a neighborhood to shreds?
According to Oxford’s Professor Lee Cronin, biological systems are complex chemical systems that control large numbers of interconnected processes by partitioning semi-permeable membranes and allowing or denying the passage of different chemicals between them.
The Cronin Group had put together “a toolbox of inorganic materials; molecular metal oxides, hybrid-functionalized polyoxometalates and coordination compounds, which allowed them to construct pre-designed complex chemical systems that have emergent properties.“
How does a simple weather pattern go from warm and cool air currents to hurricanes? How do neurons organize into neural networks. That's the rub isn't it?
The answer lies in emerging complexity. Emerging complexity involves a few simple rules and lots of interactions between individual components, to produce hurricanes in the ocean, the creatures in the desert and the plants in the tropics. What science has discovered in all these examples are a few basic principals. Quantity produces quality, the simpler the better, and the more random the interactions, the better.
Atoms to elements, to molecules, to chemical compounds, to amino acids, to proteins and enzymes, to DNA & RNA, to unicellular organism, and finally to multi-cellular organisms.
Adaptive Mutation-A Driving Force behind Evolution’s Natural Selection.
Natural selection is the guiding hand. There are at least three mechanisms that work together in evolution; heritability, mutation and natural selection. This leads to emergent complexity.
To understand the process you have to study the mechanisms behind mutation, and there are quite a few. The most salient point to keep in mind is that not all mutations are harmful. Sometimes information is added.
Look up flight of the Peppered moth to get an idea how mutations can be beneficial.
"Thousands of peppered moths turned from white to black to avoid predators by blending in with the blackened leaves on the trees. Scientists had put it down to an evolutionary fluke but have now worked out exactly what went on.
“Instead, just a single mutation in the area of their genetic code which also deals with the wing pattern was responsible for the dramatic colour change"
To understand mutations, one has to spend a great deal of time learning about the genome. A change in this genetic material leads to mutation. We're talking about the chromosomes where all this takes place. A sequence of the nucleotides AGC and T make up a gene. Where the gene is located in a string of DNA is called the locus and where one finds the A, or G, C, or T is called the site.
DNA sequences differ from one member of a species to the next. These differences are called alleles.
If we looked at all the peppered moths in a population we'd find different combinations of AGCT at a particular locus as much as 20% of the time.
The moth has two alleles at the locus that makes him either dark or light colored. If both are the same he will be either light or dark. If both are different he will be which ever alleles dominates.
There are multiple ways the alleles can change:
The gene gets duplicated
A sequence gets inserted
A sequence gets inverted
A sequence gets deleted
The smog coloring the bark made it easier to find the moth for the bird that preyed on it. Natural selection occurred because the lighter moth stood out against the dark bark.
When the smog was cleaned up, the white bark reappeared and so the darker moth stood out The bird picked him off aiding selection of the moth bearing dominant alleles for light color. The three mechanisms involved here were heritability, mutation, and natural selection.
Another excellent example of what we are talking about is antibiotic resistance in bacteria:
Persons with sickle cell are resistant to malaria.
Jews with Tay-sachs disease are resistant to tuberculosis...and there are other examples.
Darwin only laid the groundwork for current investigation. In fact, Darwin knew nothing of genetics and only in ”New Darwinism“, mostly the last decade, have scientists been able to look more closely at adaptive mutation.
"Fairly early on in our studies, Cairns and I eliminated the hypothesis that mutations were ‘directed‘ toward a useful goal."
http://jb.asm.org/content/186/15/4846.full
Macro evolution is implied by microevolution. Charles Darwin, understanding one’s incredulity, said:
"The belief that species were immutable productions was almost unavoidable as long as the history of the world was thought to be of short duration; and now that we have acquired some idea of the lapse of time, we are too apt to assume, without proof, that the geological record is so perfect that it would have afforded us plain evidence of the mutation of species, if they had undergone mutation. But the chief cause of our natural unwillingness to admit that one species has given birth to other and distinct species, is that we are always slow in admitting any great change of which we do not see the intermediate steps."
Ever seen a series of photos of a child taken while growing up? It's hard to believe that that baby becomes that man. Of course, we can visualize the process, if we put our mind to it.
Whether mutation, genetic drift, magnetism, or any other component is at work, Natural Selection is the guiding hand. Evolution is rational conceptually, reasonable, and clearly evident. There is clear understanding of the underlying mechanisms (including mutation).
PubMed has over 3,000 references to gene duplication. Check out the enzyme mutation in Langur monkeys and transport genes in yeast for starters.
To throw in a little bit more theory. Genetic drift and selection remove genetic information, but according to information theory, random noise increases genetic information. Mutation NATURALLY increases information.
Information in this context is the strings of AGCs and Ts and their arrangement.
Obviously, the number of genes or length of the DNA strand doesn't necessarily indicate complexity. There are roughly 55,000 genes in a grain of rice but only about 30,000 genes in a human genome (the C- value paradox).
Along comes ”Maxwell's Demon“ and a method of determining physical components of genomic complexity.
First we must define information:
"A recent information-theoretic (but intuitively evident) definition identifies genomic complexity with the amount of information a sequence stores about its environment."
and complexity:
"If an organism's complexity is a reflection of the physical complexity of its genome (as we assume here), the latter is of prime importance in evolutionary theory. Physical complexity, roughly speaking, reflects the number of base pairs in a sequence that are functional."
http://www.pnas.org/content/97/9/4463.full
The beauty of information theory as it is portrayed in the article on Maxwell's Demon and Biological Complexity is that it regards information as something physical whether bits in a computer or neurons in a brain. Also, that information has to be about something, and the only way that it can be considered information in this regard is if it relates to other physical objects.
Emphasis has been placed on mutation as the "driving force" behind increasing complexity. We understand that evolution is blind and that a successful result of natural selection is the obvious exception in the short run when looking at all the failed attempts.
The majority of times, as shown with emerging complex automaton and reflected in our world, species fail to arise from the mix, or because of natural selection fail to thrive. Of course, because of extinction mechanisms, all species eventually go extinct. That is a separate subject and discussed in my Hub on What Happened to the Dinosaurs.
https://discover.hubpages.com/education/What-Happened-to-the-Dinosaurs
