The term synthetic probably is used to refer to specific sequences of nucleotides that are not naturally formed i. Conversely, if I was to synthesis a gene for a protein but changing as many codons as possible without affecting the amino acid sequence - what would that be? With mutagenesis I would say it's genetic engineering, as there is no 'synthetic' element to the DNA modification, other than it is done under experimental conditions I have not seen a concrete definition, so I may well be mistaken.
So main theories of evolution are: I Lamarckism or Theory of Inheritance of Acquired characters. This theory is based on the comparison between the contemporary species of his time to fossil records. His theory is based on the inheritance of acquired characters which are defined as the changes variations developed in the body of an organism from normal characters, in response to the changes in environment, or in the functioning use and disuse of organs, in their own life time, to fulfill their new needs.
Thus Lamarck stressed on adaptation as means of evolutionary modification. Lamarckism is based on following four postulates: Every living organism is found in some kind of environment. The changes in the environmental factors like light, temperature, medium, food, air etc.
To fulfill these new needs, the living organisms have to exert special efforts like the changes in habits or behaviour.
Use and disuse of organs: The new habits involve the greater use of certain organs to meet new needs, and the disuse or lesser use of certain other organs which are of no use in new conditions.
This use and disuse of organs greatly affect the form, structure and functioning of the organs. Continuous and extra use of organs make them more efficient while the continued disuse of some other organs lead to their degeneration and ultimate disappearance. Inheritance of acquired characters: Lamarck believed that acquired characters are inheritable and are transmitted to the offsprings so that these are born fit to face the changed environmental conditions and the chances of their survival are increased.
Lamarck believed that in every generation, new characters are acquired and transmitted to next generation, so that new characters accumulate generation after generation.
After a number of generations, a new species is formed. So according to Lamarck, an existing individual is the sum total of the characters acquired by a number of previous generations and the speciation is a gradual process. Summary of four postulates of Lamarckism: Living organisms or their component parts tend to increase in size.
Production of new organ is resulted from a new need. Continued use of an organ makes it more developed, while disuse of an organ results in degeneration. Acquired characters or modifications developed by individuals during their own lifetime are inheritable and accumulate over a period of time resulting a new species.
Evidences in favour of Lamarckism: Phylogenetic studies of horse, elephant and other animals show that all these increase in their evolution from simple to complex forms. Development of present day long-necked and long fore-necked giraffe from deer-like ancestor by the gradual elongation of neck and forelimbs in response to deficiency of food on the barren ground in dry deserts of Africa.
These body parts were elongated so as to eat the leaves on the tree branches. This is an example of effect of extra use and elongation of certain organs. Development of present day limbless snakes with long slender body from the limbed ancestors due to continued disuse of limbs and stretching of their body to suit their creeping mode of locomotion and fossorial mode of living out of fear of larger and more powerful mammals.
It is an example of disuse and degeneration of certain organs.
Development of aquatic birds like ducks, geese etc. These changes were induced due to deficiency of food on land and severe competition. It is an example of both extra use skin between the toes and disuse wings of organs.Synthetic biology goes beyond genetic engineering.
It has been described as a convergence of chemistry, biology, computer science, and engineering to create a standardized, automated construction of biological systems. and the Action of Evolution: Engineering Versus Tinkering Michel Morange Received: 29 May /Accepted: 24 June /Published online: 7 August deﬁnition of synthetic biology is no easy task; the false evolution by natural selection is limited in two additional different ways.
The ﬁrst is that evolution recombines much. Neo-Darwinism or Modern Concept or Synthetic Theory of Evolution: The detailed studies of Lamarckism, Darwinism and Mutation theory of evolution showed that no single theory is fully satisfactory.
Neo-Darwinism is a modified version of theory of Natural Selection and is a sort of reconciliation between Darwin’s and de Vries theories.
Natural selection is the mechanism of evolution, the process in nature by which only the organisms that are best adapted to their environment tend to survive and reproduce, transmitting their genetic traits to the next generation.
And, in their work, synthetic biologists crucially need the optimizing action of natural selection. To give a definition of synthetic biology is no easy task; the false distinction drawn between the work of synthetic biologists and the action of evolution is of no help.
Natural selection occurs in all kind of natural populations and it is a natural selection process; whereas Artificial selection occurs in domestic populations and it is a man-made selection.
Examples of Natural selection are Darwin finches which are a group of birds of 14 species of small birds, evolved from the same species of bird on the.