Why are we losing the battle of evolution to our unicellular counterparts?

As great thinkers always said everyday is a new learning experience, it's no different for our human body. The astoundingly complex design of our Human body with all its intricate networks place a million questions before the most advance science of this age. The best single solution to a bag of questions in the million available was provided by Charles Darwin. Evolution, a very simple term which explains the most complex design. Many people have a wide variety of views about his theory of the origin of species. A few people call the bottom-line of the theory as the 'survival of the fittest' but some call it the 'survival of the species which is most adaptive'.

Here we are the fittest species on the planet with all our might and wisdom, dominating the planet for centuries now, as the dinosaurs did for about 100 million years. Remarkably we have evolved a lot more than the dinosaurs did in a number of ways. But, we have forgotten to realize a major problem. The more complex we are, slower is our rate of evolution. So here is answer to one basic question, more simple organisms are, faster they evolve.

Coming to the bottom line of Darwin's theory, he had clearly stated the evolution of any given species more specifically a trait, just depends on how much the trait helps for the survival of the species. Darwin's classical examples of the tortoises in the Galápagos Islands. The tortoises with longer necks had a selective advantage to reach out to prickly pear for food in arid areas, whereas the tortoises with short necks were not able to reach out to food available at a considerable height above the ground. So the long neck tortoises dominated and survived.

In the same lines the species which require a much lesser time for reproduction, will be able to evolve traits which increase their chances of survival. And mind you they don't have too many rules or ethics and their genetic content is very simple. So when a certain species is facing a threat against survival, they can receive genes (which are the cause for the trait or the characteristic) from organisms which can give resistance to that particular threat.

Say for example when we use a particular antibiotic against a species which causes diseases to humans, so that species faces threat. In that case, when one individual in that particular species comes to contact with an other individual of a species which has resistance to this antibiotic, they may undergo conjugation and reproduce thereby exchange genes. This is of-course a chance event. But when there are millions of this species spread in an area this chance event will have a high occurrence rate. Now what happens is, since all the individuals which does not posses this antibiotic resistant gene die the ones resistant has more space for growth and multiple exponentially. So, we have a new species which is resistant to a drug.

This is not the only case, like all organisms the replication of the DNA of the microbes are also error prone. So when the protein targeted by the antibiotic undergoes random mutation through generations, the microbe again becomes resistant. Now one thing which should strike people strongly is the multiplication rate of microbes which is very high. An organism like E.coli has a doubling time of 20 minutes. So a simple math calculation will tell us that in a day the organism will have had 72 generation of descendants in a day. While we humans may take more than 3000 years to have so many generations and the best part is not more than the 69th to 71st generations would live to see the 72nd generation. While in the case of the microbes most of them will survive through most of these generations.

It does not mean that we human beings do not have these mechanisms in place. A best example of human evolution is in the Africa population where Malaria is a major killer disease till date. The survival rate is high with individuals who have one abnormal allele of the hemoglobin beta gene (which leads to formation of sickled RBCs) and one normal allele in the Red blood cells (human beings have two copy of every gene). So when a heterozygous (dissimilar allele carrier) person is affected with the malarial parasite, they have more chances of survival because the parasite is not able to affect the sickled RBCs. This selective pressure is very high in a few regions of Africa due to the malarial parasite, this has led to the predominant presence of heterozygous individuals in the region.

The present situation is we are training our bodies not to evolve. We just take medicines for granted. How many of us know that the antibiotics we use DO NOT fight viruses which are the cause of cold. Antibiotics can just fight against secondary infections caused by bacteria like sore throat. We are advised to take specific antibiotics which will fight the secondary infections and allow our immune system to concentrate combating the viruses. If we treat ourselves without proper consultation or proper diagnosis we are just wasting our money and giving more stress to our kidneys to clear the chemical waste.

There are many physicians who clearly understand the problem and just prescribe us a normal healthy diet. But, the sad part is there are physicians who are ignorant about this danger. The scientific community is trying to find new possible anti-biotic candidates to highly resistant microbes which are evolving at a steady pace. Now its just left to us to allow out immune system to evolve and adapt.

After-all in our struggle for survival, adaptation is the best cure for any given disease and circumstance in our day to day life.

P.S: This is my first pure scientific blog and the blog is to bring awareness among my counterparts with whom I share the 21st century Biosphere.