In Somali caves was discovered the fish-“vampire”, which has no system to repair mutations in the DNA of cells. Therefore, sunlight is deadly to her.
This system restore DNA damage in a result of small mutations is available to all animals. The lack of this system is one of a million people. It is a genetic disease, the Genesis of “Nosferatu” makes such people vulnerable to sunlight. In daylight they can die.
We are talking about breakdowns in the genes DDB, HRS, ERCC and several other parts of the genome, a genetic disease called “retinitis xeroderma”. When exposed to ultraviolet radiation on the skin there is the small damage in DNA, single gaps of the spiral. When the described disease such breaks are not restored.
Apparently, people with this disease gave rise to legends about vampires and living dead who are afraid of sunlight. In reality, people with this genetic disease are prone to development of melanoma, other cancers and rarely live up to 18 years.
But it is a rare disease. In the case discovered in the caves of Somalia fish Phreatichthys andruzzii, a distant cousin of the carp, the absence of a mechanism of DNA repair is a species characteristic. This system repair DNA somehow was lost by them.
“something similar happened only with one group of animals – placental mammals. This, apparently, can say that our ancestors lived in total darkness,” says Nicholas Foulkes (Foulkes Nicholas) from the Karlsruhe Institute of Technology (Germany).
There’s no mechanism to repair DNA is not typical of other fish living in caves or at great depths where no sunlight.