This entry should virtually be point form, but i haven't bothered with the actual points. This is really just an attempt to colelct my thoughts, form a logical sequence to the argument and form points where I need to do more research. I would appreciate any feedback or additional thoughts which you think I should add.
The Scientific Method and Paradigms
Under both of the prevailing philosophies of science, Evolutionary theory resides as a strong Science. Under Popperian philosophy, Evolution has many falsification principles and has been tested on many of those principles and never yet ultimately falsified. By Kuhn's theory of Scientific revolutions, Evolution is the current biological Paradigm and it will remain so until formally trained biological scientists continually find fault and error with the predictions made by the theory and it becomes obvious that another theory is required. The new theory must explain all of the previous data better than evolutionary theory plus the new anomalies which evolutionary theory doesn't explain before a revolution will occur.
Examples of previous scientific revolutions include Copernicus et al gradually convincing Europe that the Earth was not the center of our solar system. This took several generations. The second famous example of a scientific revolution is the gradual acceptance of Evolutionary Theory in replace of the previous theory: Creationism.
Falsification Of Evolution
What principles in the theory of evolution are falsifiable? There are many falsifiable principles in evolutionary theory that would either falsify evolutionary theory outright, or cause a major reshaping of the theory. Usually multiple falsifcation principles will be touched upon before a 'revolution' will occur according to Kuhn.
1. a static fossil record;
2. true chimeras, that is, organisms that combined parts from several different and diverse lineages (such as mermaids and centaurs) and which are not explained by lateral gene transfer, which transfers relatively small amounts of DNA between lineages, or symbiosis, where two whole organisms come together;
3. a mechanism that would prevent mutations from occurring or accumulating;
4. observations of organisms being created.
5. Fossils found out of sequence
6. Demonstrating similar species have less genetic similarity than dis-similar species; i.e. showing Chicken DNA is closer to human DNA than Chimpanzee DNA
7. Demonstrating that the Earth is not Billions of years old
Every new fossil that is dug up, could potentially falsify evolutionary theory. Every new genome sequenced could falsify evolutionary theory. Every new organism found could falsify evolutionary theory.
Evolutionary theory has survived over 150 years of this constant bombardment of falsification pressure without any major strikes of falsification. It has been revised a few times in light of Mendels laws of particulate inheritence, then updating to include Genetic theory and many other advances in scientific knowledge, but the core theory remains unchallenged by observations.
The Principles of Evolutionary Theory
The core tennant of evolutionary theory has a beautifully simplistic expression. Wheresoever there is something which:
1. Replicates itself (produces offspring with hereditary information)
2. Encounters small variations in that replication (mutations)
3. There is a differential fitness (Some will replicate more than others, some will not)
there will be evolution.
*This concept has been verified many times since the creation of computers which run evolutionary models.
*Evolutionary algorithms have been used to design things
*Programs have been designed to show proof of principle
There can't be any denying this concept, so the question of the truth of Evolutionary theory as it applies to our Natural world is whether the organisms we see around us are actually the consequence of this process or not.
Darwin argued that our short history of animal husbandry was evidence enough of the existence of the three principles above (Although he didn't ever expresss evolution in those terms). Clearly anyone can see that animals pass down hereditary information with variation, and if we actively select them than we could affect their form. We had done this as a civilisation for a few thousand years and acheived amazing diversity within the species with which we have practiced it. Based on that information, if life has existed for billions of years, that could be enough time for the huge variety in life we witness today to have arisen.
From such a simple central premise 150 years ago, so much more has been discovered which has come to support evolutionary theory. Not only the peripheral information:
Discovering the Sun burns by Fission, hence billions of years old.
Discovery of Radiometric dating techniques.
but also core biological information which Darwin had no knowledge about. All of which creates a much stronger case for evolution than that originall posed by Darwin.
For a start, we discovered that Hereditary information is carried in genetic code, a system very amiable to the Descent with modification theory. The modifications could now be substantively measured. This was a HUGE leap for evolution. If evolution was wrong, then being able to quantify and exactly measure the variation in descent should surely indicate the error. But instead it has done nothing but verify it.
Sequenced genomes and found relatedness in them.
Discovered many new species in our explorations of the globe.
This will probably be expanded more, but I need to figure out the bounds between this section and the next section...
Accumulating Evidence For Evolutionary Theory
Before publishing Origin of the Species, Darwin spent 20 years collecting data to support his theory. He understood the ramifications of his theory and wanted to present the strongest case he could.
He presented much evidence for his theory including:
Since his time we have added much to the list..
Relatedness phenotypically AND genetically.
Junk DNA consistency
...more to come.
I'll revise this again soon and start working on the first section. I'll hopefully be able to fill that out pretty easily. It is the later chapters which will be data intensive and require some solid foundational research.