The optic vesicle secrete two paracrine factors:

 BMP4

 FGF8

TLS Online TPP Program

#Id: 9541

#Unit 11. Evolution and Behavior

James Hutton and Charles Lyell – Uniformitarianism

Darwin was greatly influenced by Lyell’s teachings, and he adopted uniformitarianism in his thinking about evolution.

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#Id: 9542

#Unit 11. Evolution and Behavior

Chevalier de Lamarck

Different organisms originated separately by spontaneous generation from nonliving matter.

We now see a hierarchy of species because they differ in age

Species differ from one another because they have different needs.

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#Id: 9543

#Unit 11. Evolution and Behavior

TLS Online TPP Program

#Id: 9544

#Unit 11. Evolution and Behavior

Just as muscles become strengthened by work, more strongly exercised organs attract and become enlarged by the “nervous fluid.” 

Acquired during an individual’s lifetime, are inherited—a principle called inheritance of acquired characteristics.

TLS Online TPP Program

#Id: 9545

#Unit 11. Evolution and Behavior

TLS Online TPP Program

#Id: 9546

#Unit 11. Evolution and Behavior

In the most famous example of Lamarck’s theory, giraffes must have stretched their necks to reach foliage above them, and so their necks were lengthened

The longer necks were inherited, and over the course of generations, this process was repeated, and their necks got longer and longer.