Darwin, Then and Now

Posts Tagged ‘genome’

In 1943, published in a paper entitled “Mutations of Bacteria from Virus Sensitivity to Virus Resistance,” microbiologist Salvador Luria, biophysicist Max Delbrück, and bacteriologist and geneticist Alfred Hershey discovered that mutations occur at a constant rate. In 1969, they were awarded the Nobel Prize in Physiology and Medicine “for their discoveries concerning the replication mechanism and genetic structure of virus.”

The Luria-Delbrück Experiment opened the question, are mutations inherent to microbes for the purpose of adaption to rapidly changinging environments and not for evolution? While microbe resistance through mutation is a logical mechanism for evolution, the reality is the bacteria have remained a bacteria and the virus has remained a virus. Preexistent genetic variants determine the range of mutations. Pierre-Paul Grassé, president of the French Academy of Sciences, observed, “bacteria, the study of which has formed a great part of the foundation of genetics and molecular biology … stabilized a billion years ago.”

The question is whether the mutations are the “raw material for evolution” or nature’s means for the microbes to adapt to the environment. In a 2009 review article by entitled “Darwinian evolution in the light of genomics”, published in Nucleic Acid Research, Eugene V Koonin concluded, “There is no consistent tendency of evolution towards increased genomic complexity” through mutation as expected with current evolutionary theories. Mechanisms of evolution remain beyond any known natural law.

Reflecting on the role of mutations, Grassé questioned, “What is the use of their unceasing mutations if they do not change?” Grassé concludes, “the mutations of bacteria and viruses are merely hereditary fluctuations around a median position; a swing to the right, a swing to the left, but no final evolutionary effect.” Microbes undergo constant mutations, but do not evolve – mutation stasis.

*Nucleic Acids Res. 2009 March; 37(4): 1011–1034 

Genomics offers unprecedented opportunities for testing the central tenets of evolutionary biology formulated by Charles Darwin in The Origin of Species in 1859, later modified into the Central Dogma by the Modern Synthesis during the twentieth century.

In a 2009 review article by entitled “Darwinian evolution in the light of genomics”, published in Nucleic Acid Research, Eugene V Koonin concludes “[m]ajor contributions of horizonal gene transfer… undermine the Tree of Life concept. An adequate depiction of evolution requires the more complex concept of a network or ‘forest’ of life.” 

Darwin wrote in The Origin of Species,“[a]lthough the belief that an organ so perfect as the eye could have been formed by natural selection, is enough to stagger any one; yet in the case of any organ, if we know of a long series of gradations in complexity, each good for its possessor, then under changing conditions of life, there is no logical impossibility in the acquirement of any conceivable degree of perfection through natural selection.”

Koonin continues, “[t]here is no consistent tendency of evolution towards increased genomic complexity.” Genomics has failed to demostrate increasing complexity as hypothesized by Darwin.

Evolution needs to synthesis a new mechanism to survive. To this end, Koonin suggests the possibility: “a new synthesis of evolutionary biology might become feasible in a not so remote future.” Until then, genomic evidence fails to support evolution.

Koonin, EV. 2009. Darwinian evolution in the light of genomics. Nucleic Acid Research, 37(4)1011-1034.

The anticipation around Charles Darwin’s 200^th birthday celebration passed nearly unnoticed. Few media venues ventured to highlight the day. Perhaps, the struggling economy naturally selected the sullenness.

While researchers in Germany, announced completion of the first draft of the Neanderthal genome, to coincide with the 200th anniversary of Charles Darwin’s birth, the hoped for links to human evolution are still missing.

 The genome team led by geneticist Svante Paabo after isolating 3.7 billion base pairs could only conclude:  ”We’re currently analyzing if we see evidence in the Neanderthal genome of contribution from human ancestors,” Paabo said. “That question I think is still totally open.”

Again, this big golden nugget of evolution, like the fossil record, continues as the emperor without clothes. In the Guardian, palaeontologist Simon Conway Morris writes:

 “[P]erhaps now is the time to rejoice not in what Darwin got right, and in demonstrating the reality of evolution… “Isn’t it curious how evolution is regarded by some as a total, universe-embracing explanation, although those who treat it as a religion might protest and sometimes not gently. Don’t worry, the science of evolution is certainly incomplete.”

Even the New York Times writer, Carl Safina, in an essay for the science section entitled “Darwinism Must Die So That Evolution May Live” concludes, “So let us now kill Darwin.”

 After 150 years, since the natural mechanism of evolution that Darwin was looking for is still missing, in this post-modern evolution era the birthday party fizzled.