Read aloud Is life just a coincidence? For the French molecular biologist Prof. Jacques Monod, awarded the Nobel Prize for Medicine in 1965, there is no reason to assume that the world has reserved a place for life and produced it purposefully. On the contrary, he says it is a unique stroke of luck in an otherwise inanimate cosmos, "in the indifferent immensity of the universe." Monod's central argument for the chance hypothesis is that the probability of the formation of the proteins and hereditary molecules (DNA), which are necessary for all terrestrial life forms, is extremely low. So small that it probably has not been fulfilled a second time in the universe. After Monod's consideration, it would not be a miracle if life had not existed at all.

Teleological approaches (from the Greek "telos", goal, purpose), on the other hand, assume that there are purposeful forces or laws. One can distinguish two types of goal-directedness: one given from outside and one inherent in matter itself. The first type is based on a planning authority, a cosmic mastermind who controls the events. For example, he could have consciously selected from the billions of possibilities of complex molecules the few that were essential to the first organisms. The emergence of life would then not be due to a whim of nature, but to a "divine" spark or a cosmic script.

The other teleological variant assumes that matter itself strives to achieve a particular developmental goal. The Greek philosopher Aristotle called this principle 2300 years ago as entelechy (Greek for "what his goal carries") and postulated as an essential feature of life. To this day, vitalists rely on a mysterious life force that should not be physically and chemically detectable in principle.

The philosopher Prof. Bernd Olaf Küppers of the University of Jena rejects both approaches as unscientific: "The chance hypothesis is fundamentally unprovable, the teleological approach is fundamentally irrefutable." Display

The evolution of life on earth is likely to be unique, as it actually happened, and to have been caused by countless coincidences. But it does not follow that there have been and will not be any other and even similar developments elsewhere in the universe.

Prof. Norman R. Pace of the University of California at Berkeley, therefore, emphasizes a very different viewpoint: "It may not be at all about how probable the origin of life is, but how probable it is that life, once created, survived and begins to dominate his planet. "

=== Rüdiger Vaas

© science.de

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