'Lamarckism'

sensu Darwin

'Lamarckism'

sensu Lamarck

Environmental feed-back, acquired characteristics are inherited by descendants.

There is a feed-back from environment to the species, through the individual.

Example: a giraffe reaches for leaves sitting higher, it gets a longer neck, and its off-spring inherits longer necks.

The mechanism is an environmental interaction.

Animals evolved from 'gelatinous' particles and plants from 'mucilaginous' particles by heat and electricity.

An inner force improves species to advance up the scala natura (following Robinet).

Bodies of organisms shaped by behaviour, caused by needs.

Example: giraffe gets a longer neck because it needs to reach for leaves sitting higher. Mechanism is an inner force, a need for perfection.

 

Cuvier:

- species go extinct

- extinct species may be very similar to extant

- extinct species can be classified by same branching scheme

 

Lamarck:

- species are variable

- any classification will have to deal with intermediates

- fossils are spot-samples from a continuous history