This book is written with a strong emphasis on genetics and molecular biology of evolution for both professionals and also for general readers. However, I must warn that it gets little technical at places and a reasonable background in molecular biology will be helpful.
The flow of information is a key to the biological evolution. All elementary processes of life are governed by information; it is stored in the genome of the organism and is expressed by a process through which the genetic information is continually re-evaluated by permanent interactions with the physical environment to which it is exposed. In this way, the living organism is built step by step into a hierarchically organized network of unmatched complexity. The fact that all phenomena of life are based upon information and communication, and this is indeed the principal characteristic of living matter. Without the perpetual exchange of information at all levels of organization, the functional order in the living organism could not be sustained.
Molecular evolution may act in different ways, through protein evolution, gene loss, differential gene regulation and RNA evolution. Natural selection and adaptation modulated the first primitive cells on this planet all the way into the human system; mathematical modeling and also the genome comparisons have provided strong leads in this regard. An unprecedented desire for life to sustain, persevere, grow, and evolve in most inhospitable environments of the planet such as soil rich in arsenic, highly alkaline medium, anoxic conditions under salty water, and high temperature deep under the ocean close to the vents of volcanic activity all strongly support the principle of adaptation.
Primarily it is not the genes that make us different, but it is regulatory regions accounts for some of our uniquely human traits. We have lost 510 sizeable chunks' of regulatory DNA despite the fact that it is retained by other animals like chimps, mice and chickens. Before the human genome sequence was published, it was estimated that there were about 100,000 genes, but it turned out to be about 20,000. The human genome is less complex than it was previously thought. It is this missing DNA that provides us the clue of what makes us so different from others.
Evolution of life is an adaptive process and this is clearly illustrated in molecular immunology, where antibodies are synthesized to recognize unknown invaders. The genetic engineering and evolutionary change resulting in genome restructuring in the immune system is a fine example of adaptation. In fact, recently there are numerous reports that early humans, when they left Africa for Europe and Asia were exposed to new infections. Now genetic evidences suggest that there were significant interbreeding of humans with Neanderthals, Denisovans and other hominins that offered genetic resistance of humans to infections in their new world. An international group of scientists completed the sequence of the Neanderthal genome in May 2010. The results indicate breeding between humans and Neanderthals as the genomes of non-African humans have 1-4% more in common with Neanderthals than do the genomes of sub-Saharan Africans.
The author in this book takes a view contrary to generally held opinion of many molecular evolutionists. He states that innovation and not selection is the critical issue in evolution, because innovation creates novelty. Without variation and novelty, selection has nothing to act upon. The living organisms actively change themselves thorough genome modification. The author argues that conventional evolutionary theory assumes inherited novelty, the result of chance or accident, and Darwin's idea of adaptive change from natural selection applied to countless random small changes over long periods of time. The inevitable errors in the replication process, the accidental, stochastic nature of mutations are still the prevailing and widely accepted wisdom on the subject, the author claims. The author suggests that the capacity to change is itself adaptive, and overtime, conditions inevitably change, and organisms that acquire novel inherited functions have the greatest potential to survive. He adds further that the conventional evolutionary theory treats the genome as read only memory (ROM) subject to change by stochastic damage and copying errors. It has now become apparent that the genome is read-write (RW) memory system subject to non-random change by dedicated cell functions. Cell mediated inscriptions occur at all time scales ranging from the single cycle to evolutionary epoch. Therefore, the author claims that we must incorporate the capacity of living organisms to alter their own heredity in the current ideas of molecular evolution.
Evolutionists including molecular biologists invoke the principles of Darwinism in interpreting their results. The fact that traditional evolution did not include genetics means that not much was known about that at that time but the ideas are still the same. Genes help human population to adapt to certain environmental conditions. An example of advantageous mutation in a population was traced in human genome, but it is harder and subtler to trace than originally anticipated. Using the statistical method they have found many less dramatic mutations that, for example, help highland Tibetans survive high altitude, and Yupik Eskimos to stay warm efficiently (1). How does an organism whose internal temperatures vary with ambient temperature. A Poikilotherm is shown to sense temperature of its environment using rhodopsin as a thermo sensor, which is actually a visual sensor (2). The photosynthetic apparatus of cryptophytes algae has pigments farther apart than is expected for efficient functioning. The authors find that its higher efficiency is partly due to quantum physical process (3). Does speciation occur within a population, sympatrically? Mating preferences can halt movement of genes within a population. The work of Van Doorn et al., gives credibility to this concept of sympatric speciation and suggests that both local adaptation and sexual selection may play a far more important role in speciation than previously thought (4). A bacterial strain GFA-1 of the Halomonadaceae is able to substitute arsenic instead for phosphorus to sustain growth. The substitution of this element for phosphorus in DNA and RNA has profound evolutionary significance in Darwinian language (5).
Digital evolution is another great way of understanding biological evolution. Chris Adami of Caltech came up with software for systematic study of evolutionary process that gave rise to the computer world of Avida where the life form can evolve. At Michigan State University at East Lansing, Charles Ofria's computers developed digital microbes called Avidians. They consume computing time as "food", have equations for genetic codes, they self replicate, mutate and evolve into new more intelligent artificial life forms. In other experiments, digital pets have been created with rudimentary memory and symmetrical brains. These experiments offer as fine models to study and understand the strength of natural selection and adaptation (6).
The author's comment that "The perceived need to reject supernatural intervention unfortunately led to the pioneers of evolutionary theory to erect a priori philosophical distinction between the "blind" process of hereditary variation and all other adaptive functions," is highly unfair. Most biologists are realists and believe in theory and experimental evidences in support of the theory. No evolutionists have interpreted his/her data to denounce faith based arguments. Darwin toyed with his idea for 20 years before he published his work. Most scientists and philosophers at his time were ordained ministers and people's belief in the book of Geneisis was unshakable. Darwin himself a conservative Christian took a great deal of courage to publish his work and there were no attempts by Darwin or by anyone to reject people's belief in supernatural intervention.
The flow of information is a key to the biological evolution. All elementary processes of life are governed by information; it is stored in the genome of the organism and is expressed by a process through which the genetic information is continually re-evaluated by permanent interactions with the physical environment to which it is exposed. In this way, the living organism is built step by step into a hierarchically organized network of unmatched complexity. The fact that all phenomena of life are based upon information and communication, and this is indeed the principal characteristic of living matter. Without the perpetual exchange of information at all levels of organization, the functional order in the living organism could not be sustained.
Molecular evolution may act in different ways, through protein evolution, gene loss, differential gene regulation and RNA evolution. Natural selection and adaptation modulated the first primitive cells on this planet all the way into the human system; mathematical modeling and also the genome comparisons have provided strong leads in this regard. An unprecedented desire for life to sustain, persevere, grow, and evolve in most inhospitable environments of the planet such as soil rich in arsenic, highly alkaline medium, anoxic conditions under salty water, and high temperature deep under the ocean close to the vents of volcanic activity all strongly support the principle of adaptation.
Primarily it is not the genes that make us different, but it is regulatory regions accounts for some of our uniquely human traits. We have lost 510 sizeable chunks' of regulatory DNA despite the fact that it is retained by other animals like chimps, mice and chickens. Before the human genome sequence was published, it was estimated that there were about 100,000 genes, but it turned out to be about 20,000. The human genome is less complex than it was previously thought. It is this missing DNA that provides us the clue of what makes us so different from others.
Evolution of life is an adaptive process and this is clearly illustrated in molecular immunology, where antibodies are synthesized to recognize unknown invaders. The genetic engineering and evolutionary change resulting in genome restructuring in the immune system is a fine example of adaptation. In fact, recently there are numerous reports that early humans, when they left Africa for Europe and Asia were exposed to new infections. Now genetic evidences suggest that there were significant interbreeding of humans with Neanderthals, Denisovans and other hominins that offered genetic resistance of humans to infections in their new world. An international group of scientists completed the sequence of the Neanderthal genome in May 2010. The results indicate breeding between humans and Neanderthals as the genomes of non-African humans have 1-4% more in common with Neanderthals than do the genomes of sub-Saharan Africans.
The author in this book takes a view contrary to generally held opinion of many molecular evolutionists. He states that innovation and not selection is the critical issue in evolution, because innovation creates novelty. Without variation and novelty, selection has nothing to act upon. The living organisms actively change themselves thorough genome modification. The author argues that conventional evolutionary theory assumes inherited novelty, the result of chance or accident, and Darwin's idea of adaptive change from natural selection applied to countless random small changes over long periods of time. The inevitable errors in the replication process, the accidental, stochastic nature of mutations are still the prevailing and widely accepted wisdom on the subject, the author claims. The author suggests that the capacity to change is itself adaptive, and overtime, conditions inevitably change, and organisms that acquire novel inherited functions have the greatest potential to survive. He adds further that the conventional evolutionary theory treats the genome as read only memory (ROM) subject to change by stochastic damage and copying errors. It has now become apparent that the genome is read-write (RW) memory system subject to non-random change by dedicated cell functions. Cell mediated inscriptions occur at all time scales ranging from the single cycle to evolutionary epoch. Therefore, the author claims that we must incorporate the capacity of living organisms to alter their own heredity in the current ideas of molecular evolution.
Evolutionists including molecular biologists invoke the principles of Darwinism in interpreting their results. The fact that traditional evolution did not include genetics means that not much was known about that at that time but the ideas are still the same. Genes help human population to adapt to certain environmental conditions. An example of advantageous mutation in a population was traced in human genome, but it is harder and subtler to trace than originally anticipated. Using the statistical method they have found many less dramatic mutations that, for example, help highland Tibetans survive high altitude, and Yupik Eskimos to stay warm efficiently (1). How does an organism whose internal temperatures vary with ambient temperature. A Poikilotherm is shown to sense temperature of its environment using rhodopsin as a thermo sensor, which is actually a visual sensor (2). The photosynthetic apparatus of cryptophytes algae has pigments farther apart than is expected for efficient functioning. The authors find that its higher efficiency is partly due to quantum physical process (3). Does speciation occur within a population, sympatrically? Mating preferences can halt movement of genes within a population. The work of Van Doorn et al., gives credibility to this concept of sympatric speciation and suggests that both local adaptation and sexual selection may play a far more important role in speciation than previously thought (4). A bacterial strain GFA-1 of the Halomonadaceae is able to substitute arsenic instead for phosphorus to sustain growth. The substitution of this element for phosphorus in DNA and RNA has profound evolutionary significance in Darwinian language (5).
Digital evolution is another great way of understanding biological evolution. Chris Adami of Caltech came up with software for systematic study of evolutionary process that gave rise to the computer world of Avida where the life form can evolve. At Michigan State University at East Lansing, Charles Ofria's computers developed digital microbes called Avidians. They consume computing time as "food", have equations for genetic codes, they self replicate, mutate and evolve into new more intelligent artificial life forms. In other experiments, digital pets have been created with rudimentary memory and symmetrical brains. These experiments offer as fine models to study and understand the strength of natural selection and adaptation (6).
The author's comment that "The perceived need to reject supernatural intervention unfortunately led to the pioneers of evolutionary theory to erect a priori philosophical distinction between the "blind" process of hereditary variation and all other adaptive functions," is highly unfair. Most biologists are realists and believe in theory and experimental evidences in support of the theory. No evolutionists have interpreted his/her data to denounce faith based arguments. Darwin toyed with his idea for 20 years before he published his work. Most scientists and philosophers at his time were ordained ministers and people's belief in the book of Geneisis was unshakable. Darwin himself a conservative Christian took a great deal of courage to publish his work and there were no attempts by Darwin or by anyone to reject people's belief in supernatural intervention.
No comments:
Post a Comment