The replicated region appears as a replication bubble within the nonreplicated DNA. 

TLS Online TPP Program

#Id: 9552

#Unit 11. Evolution and Behavior

Gradualism is Darwin’s proposition that the differences between even radically different organisms have evolved by small steps through intermediate forms, not by leaps

TLS Online TPP Program

#Id: 9553

#Unit 11. Evolution and Behavior

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

TLS Online TPP Program

#Id: 9554

#Unit 11. Evolution and Behavior

Alfred Russel Wallace - Who was collecting specimens in the Malay Archipelago, had independently conceived of natural selection

TLS Online TPP Program

#Id: 9555

#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: 9556

#Unit 11. Evolution and Behavior

TLS Online TPP Program

#Id: 9557

#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. The problem was serious because, according to the prevailing belief in blending inheritance, variation should decrease, not increase.