Phosphorylation of Whi5 promotes its export out of the nucleus, allowing the transcription factor complex SBF to induce transcription of the G1/S phase cyclin genes CLN1 and CLN2.

TLS Online TPP Program

#Id: 7040

#Unit 11. Evolution and Behavior

Populational change is Darwin’s hypothesis that evolution occurs by changes in the proportions (frequencies) of different variant kinds of individuals within a population.

TLS Online TPP Program

#Id: 7041

#Unit 11. Evolution and Behavior

 Natural selection was Darwin’s brilliant hypothesis, independently conceived by Wallace, that accounts for adaptations, features that appear “designed” to fit organisms to their environment.

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#Id: 7042

#Unit 11. Evolution and Behavior

TLS Online TPP Program

#Id: 7043

#Unit 11. Evolution and Behavior

Where, though, do these hereditary variations come from? This was the great gap in Darwin’s theory, and he never filled it.

TLS Online TPP Program

#Id: 7044

#Unit 11. Evolution and Behavior

Orthogenesis - “Straight-line evolution,” held that the variation that arises is directed toward fixed goals.

TLS Online TPP Program

#Id: 7045

#Unit 11. Evolution and Behavior

 Mutationist - Theories were advanced by some geneticists who observed that discretely different new phenotypes can arise by a process of mutation.