When there is every thing same from their genes to their phenotype so then why they don't have same fingerprints?
Identical twins have, despite the name, neither identic fingerprints nor identic genetic fingerprints.
Fingerprints: According to the papers listed below the fingerprints show higher similarities (the "structure" is the same), but they can be distinguished and are not the same.
- On the similarity of identical twin fingerprints
- Can identical twins be discriminated based on their fingerprints?
Genetic Fingerprint: Although identic (or monozygotic) twins share the same DNA, they are not the same and can still be distinguished with a DNA fingerprint, if enough regions are analyzed. The difference comes from small mutations (so called "single nucleotide polymorphisms", one base mutations) which occur in each of us individually. The other difference comes from epigenetic modifications of our genome (basically adding methyl groups to our DNA) which are also not the same between identic twins (there is an interesting video on this on Youtube). However, when using standard forensic kits it is usually not possible to discriminate between identical twins. Differences are detected with whole genome sequencing.
Have a look at these publications:
You might expect identical twins to have the same fingerprints as twins have virtually indistinguishable DNA. The distinguishing nature of physical characteristics of a person is due to both the inherent individual genetic diversity within the human population as well as the random processes affecting the development of the embryo. The same would then be true of clones of a person.
In the case of fingerprints, the genes determine the general characteristics of the pattern. Fingerprint formation is similar to the growth of capillaries and blood vessels in angiogenesis. The general characteristics of the fingerprint emerge as the skin on the fingertip begins to differentiate. However, the flow of amniotic fluids around the fetus and its position in the uterus changes during the differentiation process. Thus, the cells on the fingertip grow in a microenvironment that is slightly different from hand to hand and finger to finger. The finer details of the fingerprints are determined by this changing microenvironment. A small difference in microenvironment is amplified by the differentiation process of the cells. There are so many variations during the formation of fingerprints that it would be virtually impossible for two fingerprints to be alike.
Therefore, fingerprints aren't entirely a genetic characteristic. They are a part of a ‘phenotype’ which means they are determined by the interaction of an individual’s genes and the intrauterine environment.
Overall, identical twins’ fingerprints tend to be similar. Before genetic testing, the similarity of twins’ fingerprints was used to determine whether they were identical or fraternal. But there always will be subtle differences making even their fingerprints unique.