Is there Supreme Fitness in Evolution?

Richard Lenski of Michigan State University has grown Escherichia coli bacteria since 1988. Even after 58,000 generations, he found that no supreme bacteria were produced. He expected that someday the bacteria would create the ultimate fit entity that was much stronger than their evolutionary predecessors. What he found was that evolution slowed but continued to adjust and change. 

The findings are significant in that it is assumed that eventually all creatures max out in their development. This is not true. As the evolutionary process develops, it never really hits its maximum peak. New peaks are always in sight so the species continues to develop. 

There is an assumption that biological change is a result of environmental change. If an environment stays the same, a species will reach its biological peak and any further mutations will force it downward into a less competitive stance. Decline becomes a type of biological crash whereby further adaptations put the system out of equilibrium and encourage its decline.

The authors do not go this far in their analysis but what if each creature comes with a DNA blue print or destiny for development? The changes in the environment will place pressure on the species to adapt either fast or slow but does not end that development. Adaption is always lagging as an effect because of constant pressures from the environment.  If the DNA cannot handle this change, or the amount of pressure, the species dies as the dinosaurs did when their environmental collapsed. 

If this were true then it would be possible to assume that species can handle environment changes if these changes are slow enough as to not overwhelm the DNA structure of the entity. Bacteria changes fast because they are a small entity within a larger system and therefore are sensitive to small environmental adjustments. Dinosaurs change slowly as they are a larger entity within a system and do not feel the same sensitivity of pressures. 

The bacteria in the experiment at MSU were adapting based upon the mechanisms of their DNA in an effort to catch up to the environment. As they came closer to homeostasis, they continued to develop but at a slower rate due to the fewer environmental pressures. Yet that artificial environment does not define their full developmental process and they will continue to grow regardless.

At present the researcher has concluded that there is no supreme fitness for bacteria and that they will continue to develop even at a slower pace.

MSU Press Release

Discoveries in the Red Queen Hypothesis and Evolutionary Arms Race

Researchers have lent credibility to the concept of an evolutionary arms race. Charles Marshall, a biology professor and the director of the UC Berkeley Museum of Paleontology, states, “But we found that a decrease in the origin of new species is just as important as increased extinction rate in driving mammals to extinction.”(UC Berkely News Center, 2013) Their findings help highlight the concept that diversity loss of species is a sign that the environment has overwhelmed them.

This hypothesis was originally developed by Leigh van Valen who indicated that the probability of a species survival was based in its competitive abilities with the environment. The environment in this case is other species as well as the life sustaining resources like food and water. As species reproduces, they create opportunities to develop stronger adaptations (new forms) that are better aligned to environmental threats. Generally, the more a species reproduces the more successful it will be due to it s pace of adaptation. Is it any wonder cockroaches are one of the strongest bio-groups in the world?

Often called The Red Queen Hypothesis it helps explain why species often grow and then fundamentally collapse into extinction. Based off of the a character in the book “Through the Looking Glass” by Lewis Carroll which describes the Red Queen’s explanation to Alice of Wonderland, “it takes all the running you can do, to keep in the same place.” Researchers have confirmed that the concept of evolution as a continuous evolving entity for survival was correct.

Results reported in the June 20^{th, 2013} Journal of Science Express indicate that species must continuously adapt to a declining environment by developing new forms or they themselves will become extinct. As the species reaches its environmental carrying capacity it  begins to decline as predators and lack of resources take their toll. Species compete against a host of other species in the environment and continue to change to protect themselves and spread their genetic material.

The researchers studied 19 mammals and found that many of them had their origins from around 66 million years ago. Their histories indicate a wide variety of related species. As their diversity decreases it also mirrors the decline in their over species because they cannot adapt to the overall environmental difficulties. It helps people understand that the system is never in full equilibrium and must increase or decline.

Taking a historical perspective allows for analysis over a greater time. Historical footprints such as fossils of previous adaptations with comparison to existing creatures helps to show how a particular species has grown or declined based upon its biodiversity. The more variability in its genetic diversity the stronger the survival probability when the environment changes. In the case of horses and elephants, the biodiversity is decreasing which means that they are less able to adapt to the modern environment. Humans are not immune to these adaptations and will continue to develop new forms of life to compete not only against other species (i.e. parasites and bacteria) but also the environment itself (overcrowding, global warming, food shortage, etc…).

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