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Mobile genetic elements

on Sat Sep 09, 2017 11:10 am
First of all, it is necessary to understand what is evolution? The change of specie and it's adaptation, over time, according to the challenges and circumstances presented by environment is known as evolution. These changes are required to pass on to future generations so that, they become more and more fine-tuned with the passage of time. Even though this explanation is a fact but still specific Dynamics and mechanisms have not yet delineated. A question that most importantly emerge is the extent of control of an organism or specie over this evolution. Evolvability, if presented, would be helpful to organisms in rapid production of novel traits in the progeny. A mechanism of evolution has been introduced by William Brown, that explains the evolvability as a degree of directed adaptation. This shows that evolution is not a random process, but a dynamic one that involves altruistic genes, which includes genetic elements that are shared between organisms and which transpose within the genome, having the ability to mobilize to different locations and change genetic expression. This ability allows the organisms to produce different profiles of genetic expression, which gives flexibility and diversity in generating phenotypes that are better adapted to the environmental condition. Moreover, altruistic genes involves the exchange of genetic material by membrane bounded vesicles e.g., in viruses and bacteria. These exchanges are not necessarily pathogenic i.e., disease-causing. According to research carried out by NASA, it has been demonstrated that such exchange of genetic material in Archea takes place due to environmental stress condition. This enables the organisms to adapt to the environmental stress by rapidly changing their genotype and hence phenotypes diversity diversity
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Re: Mobile genetic elements

on Tue Sep 19, 2017 2:06 pm
With the greatest respect for your understanding and the wide range of your interests, I would like to clarify the process of evolution a bit.

First, there is no "direction" to evolution. It is driven by random processes, mutation and lateral transposition. Most mutations are either lethal or have no effect. We consider them neutral.

Second, evolution is a process that occurs on the molecular scale and appears on the scale of the whole organism. It does not happen to the organism directly.

Third, the process previously described as "natural selection" is better described as peak climbing in a fitness landscape. That landscape has bumps and ridges and is multi-dimensional (more than 3 dimensions). Organisms that climb the peaks have greater reproduction so their genes come to dominate the local group. If the genetic distance becomes such that one group can no longer mate with another group, we have speciation. Isolated populations tend to break off from their original groups this way.

So Darwin's wrens grew beak sizes for different seed sizes and those seeds could be harvested at different times of the year. Estrus cycles shifted and the new species no longer mated at the same time as the old species. They became separate species, according to the definition of "species".

On the molecular level, the original group had an operon (a set of genes,) that controlled beak size. Wrens with the more adaptive beak size ate more and therefore had more eggs.

Fourth, speciation is usually graphed by a tree structure. Every species branches off from another species. On the molecular level, the difference between two genomes, called the genetic difference, follows that tree pattern, In fact, that is the criterion for the shape of the tree.

Certain operons, such as the ones that control the maintenance and reproduction of DNA, are immortal. They go back hundreds of millions of years. We share them with trees, fish and bacteria. Tracing the operons back from species to species defines the tree's broad outline. This is the Tree of Life. At the root is a single organism, probably a member of the order we call Archaea. This single original living thing is the LUCA, the Last Universal Common Ancestor of all life.

This is the basis of molecular biology today. It is fascinating.
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Re: Mobile genetic elements

on Wed Sep 20, 2017 12:59 pm
Your understanding and knowledge of evolution, molecular and genetics is applauded by me brother and I thank you for sharing this knowledge for many who don't know it. However, this is an article which citation I forgot to add.
Human indeed evolve as a result of neutral mutations or those mutations that happens in germ cells and those that can be inherited to future generations. Our environmental factors contribute to mutations too, they are either silence or lethal e.g. cancer. So all these definition of evolution are taken in consideration. Smile Smile
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