Sign Systems Studies

Volume 31, Issue 2, 2003

Kalevi Kull
Pages 589-602

Ladder, tree, web
The ages of biological understanding

Fundamental turns in biological understanding can be interpreted as replacements of deep models that organise the biological knowledge. Three deep models distinguished here are a holistic ladder model that sees all levels of nature being complete (from Aristotle to the 18th century), a modernist tree model that emphasises progress and evolution (from Enlightenment to the recent times), and a web model that evaluates diversity (since the 20th century). The turn from the tree model to the web model in biology includes (1) a transfer from modern to postmodern approaches, (2) a shift of semiotic threshold to the border of life, and (3) building the semiotic models of living systems, i.e., the rise of biosemiotics.