Recently, some scientists from NASA have claimed that there may be a black hole like structure at the centre of the earth. We show that the existence of life on the earth may be a reason that this black hole like object is a black brane that has been formed from biological materials like DNA. Size of this DNA black brane is 109 times longer than the size of the earth's core and compacted interior it. By compacting this long object, a curved space-time emerges, and some properties of black holes emerge. This structure is the main cause of the emergence of the large temperature of the core, magnetic field around the earth and gravitational field for moving around the sun. Also, this structure produces some waves which act like topoisomerase in biology and read the information on DNAs. However, on the four-dimensional manifold, DNAs are contracted at least four times around various axis's and waves of earth couldn't read their information. While, by adding extra dimensions on 4 +n-dimensional manifold, the separation distance between particles increases and all of the information could be recovered by waves. For this reason, each DNA has two parts which one can be seen on the four-dimensional universe, and another one has existed in extra dimensions, and only it's e_ects is observed. This dark part of DNA called as a dark DNA in an extra dimension. These dark DNAs not only exchange information with DNAs but also are connected with some of the molecules of water and helps them to store information and have memory. Thus, the earth is the biggest system of telecommunication which connects DNAs, dark DNAs and molecules of water.