If one were to look deep in the earth, you would see layers upon layers of rocks filled with fossils of incredible looking creatures worthy of the SyFy channel. From strange worm like beasts to massive dinosaurs and finally to mankind, these fossils provide a rare glimpse into the past to see evolution at work. Even today you can see examples of evolution. Just look at the platypus. It’s a creature with a duckbill, lays eggs, lactates, and is poisonous. This bizarre mammal possesses a genetic similarity with both reptiles and birds and is thought to have split and evolved separately from other mammals about 166 million years ago (“Platypus Genome Reveals Secrets of Mammal Evolution”). Although evolution has been constantly challenged, especially by religious groups, it’s pretty safe to say that we have become comfortable with the idea that evolution occurs through a gradual time span and natural selection. However, this idea has come under fire from a controversial theory that states the evolution of species comes from a rapid and accidental process.
As a student in a Prehistoric Life class at UNC Chapel Hill, I can honestly say that I had never heard of the theory of accidental speciation, which means creation of new species, until I found the article, “Accidental Evolution: the real origin of species”. In my Prehistoric Life course, the professor teaches us everything we need to know about how life came to be and how and why life evolved into the creatures that live in the modern world. Evolution is both a fact and a theory. Evolution itself is a fact (yes evolution did happen and no there is no way you can get around it) but the way it occurred is still a theory.
Currently in the scientific community, evolution is literally defined as a series of partial or complete and irreversible transformations of the genetic composition of populations, based principally on altered interactions with the environment. The way that the genetics of a particular creature changes is due to natural selection, a slow and gradual process approached by Charles Darwin where animals change to better suit their environment. For example, the finches on the Galapagos Islands near South America have varying size of beaks but they are closely related. These finches’ beaks changed due to the types of food the birds were eating. The birds that eat insects have small, thin beaks. These beaks are perfect for snatching insects. The finches that eat large seeds have large, wide beaks that can grasp and crack large seeds.
Natural selection does have a major role in evolution. However, according to Mark Pagel, an evolutionary biologist at the University of Reading, UK, natural selection does not explain what causes the creation of new species. In fact, the trigger that creates new species has puzzled scientists for decades. In general, the majority of biologists view the term ‘species’ to be a group of organisms that can reproduce among themselves but not in other groups (“Accidental Evolution: The Real Origin on Species”). Therefore, in order for one species to branch off into two, or perhaps more than two, species, a division of the initial species must become incapable of reproducing with the others. According to natural selection, the creation of new species may occur when a few groups within a species drift apart to different environments, then each group adapts to the different climates, types of food, etc. Through DNA sequencing technology, Pagel was able to obtain 101 evolutionary trees to test and created the hypothesis that “if new species are the sum of a large number of small changes then this should leave a telltale statistical footprint in their evolutionary lineage” (Accidental Evolution: The Real Origin of Species”).
In order to prove evolution was due to gradual and small evolutionary changes through natural selection, the results of the DNA tests would have to produce a normal distribution (“Accidental Evolution: The Real Origin of Species”). Normal distribution is a curve on a graph, such as the one featured below, with the majority on the results in the middle. In other words, the heights of females in America would vary greatly, but the majority would be around 5 ft 4in tall. The majority would be the greatly raised curve in the dead center of the graph featured below.
However, Pagel and his associates found that their findings did not fit a normal distribution. Instead it fit an exponential distribution, as seen in the figure below. An exponential distribution occurs when one is waiting for a single and rare event to happen (“Accidental Evolution: The Real Origin of Species”), such as the time interval from one exam to another.
After running the tests, Pagel discovered that his research was leading him away from a conclusion of gradual change and towards a change that is rapid and singular. All in all, if his conclusion is correct, then natural selection slowly influences species already in existence, but most of evolution of new species completely unpredictable (“Accidental Evolution: The Real Origin of Species”). Currently, other evolutionary biologists are not accepting Pagel’s theory.
Although it is very unlikely that any of you readers are evolutionary biologists, this research is still important to you and to all other people no matter what major you have or what direction in life you are taking. If Pagel’s research is correct, then humanity could have started differently. Instead of slowly branching off from our monkey cousins, our entire existence could be a mere accident. In fact, the many species of animals on this planet could have evolved not by gradual improvement by natural selection, but by accident as well.
Works Cited
“Accidental Evolution: The Real Origin of Species.” 13 March 2010. http://ehis.ebscohost.com/ehost/detail?vid=24&hid=118&sid=d9a2e56e-afcc-4c 3a-8bcd-7602ccaebb5e%40sessionmgr111&bdata=JnNpdGU9ZWhvc3QtbGl2ZSZzY29wZT1zaXRl#db=aph&AN=48668431
“Platypus Genome Reveals Secrets of Mammal Evolution.” 7 May 2008. http://news.nationalgeographic.com/news/2008/05/080507-platypus.html
Images:
Evolution of Man:
http://www.truthtree.com/evolute.shtml
Normal Distribution:
http://www.tushar-mehta.com/excel/charts/normal_distribution
Exponential graph :
http://www.itl.nist.gov/div898/handbook/eda/section3/eda3667.htm
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