Dani De Waele | PubMed Health

PubMed2002

Epigenetics: a challenge for genetics, evolution, and development?

In this paper, it is argued that differences in how one relates the genome to its surrounding contexts leads to diverse interpretations of the term epigenetics. Three different approaches are considered, ranging from gene-centrism, over gene-regulation, to dynamic systems approaches. Although epigenetics receives its widest interpretation in a systems approach, a paradigmatic shift has taken place in biology from the abandonment of a gene-centric position on to the present. The epistemological and ontological consequences of this shift are made explicit.

Animals↗

PubMed2002

Theories in early embryology: close connections between epigenesis, preformationism, and self-organization.

In current biological and philosophical literature, the use of the terms epigenesis and epigenetics has increased tremendously. As these terms are often confused, this paper aims at clarifying the distinction between them by drawing their conceptual and historical evolutions. The evolution of the term epigenesis is situated in the context of early embryological studies. Departing from Aristotle's natural philosophy, it is shown that epigenesis gained alternating attention from the 17th century onwards, as it was introduced into neo-classical embryology and considered to be the opposite of the preformationist tradition. Where preformation stated that the germ cells of each organism contain preformed miniature adults that unfold during development, epigenesis held that the embryo forms by successive gradual exchanges in an amorphous zygote. Although both traditions tried to explain developmental organization, religious and metaphysical arguments on the conception of embryonic matter as either active or passive determined the scope of their respective explanations. It is shown that these very arguments still underlie the use of gene-centric metaphors in the molecular revolution of the 20th century.

Animals↗