Does epigenesis explain evolution?


Epigenetics deals with a question to which scientists still have no clear answer: How far are we and all living things preprogrammed by our genes, and how much can the environment change and shape this program? The answer lies in the epigenetic processes of our cells. These molecular mechanisms ensure - depending on external circumstances - that genes are read more or less. The information stored there in the DNA sequence is not changed.

  • In epigentic regulation, enzymes change certain sections of the DNA in order to be able to read them better or less well. However, this does not affect the nucleotide sequence of the DNA strand, but rather the level "above", which is why we speak of epigenetics (from Greek: epi = over). In this way, cells control, among other things, when they produce which proteins - and in what quantities.
  • The mechanism has long been neglected by genetic researchers. The cell nucleus can react to environmental influences via epigenetics and regulate which genes are switched on and off depending on when and to what extent. Epigenetic mechanisms also make the same genetic material of the most diverse cells flexible: how skin, heart or intestinal wall cells use their identical DNA sequences can also depend on environmental factors under epigenetic regulation.
  • Epigenetic regulators influence how tightly packed - and therefore accessible - individual chromosome areas are present. Access is initially regulated by attaching or detaching small chemical groups. The genome's marking pattern, which can be modified in this way, is then read by special enzymes that initiate further steps and, for example, switch genes on or off.
  • The discovery of epigenetics has overturned a long-cherished dogma of biology: the idea that the properties of an organism are invariably determined by the genetic material inherited at birth. In fact, epigenetics allows even subtle environmental changes to access our genetic make-up. Illnesses or changes in personality traits can also be epigenetically influenced.