TF: Pan Pan Jiang
T HEO RIGIN OF THE S PECIES:C HAPTERS 7/8(I NSTINCT AND HYBRIDISM )
Darwinchoosesto focusonseveral highly complexbehaviorsas thebehavioral equivalents ofthe eyeand
other“organsof extreme perfection andcomplication”(Chapt6). Namethree ofthese behaviors
highlighted by Darwin.
Darwin highlights comb-building in honeybees, cuckoo parasitism, and “slave-making” in ants.
Outline howDarwin supposes these behaviorsto have evolved.
Darwin draws a parallel between physical structures and behavior, making the case that slight
variations in behavior that are advantageous will be preserved by natural selection; over time, even
the most complex behaviors can be developed. He argues that finding evidence of gradations is
possible. Darwin suggests that the stepwise evolution of hive-bee cell-building is resource-driven,
with the need for efficient storage of large quantities of honey is likely to have led to the evolution of
What, inDarwin’s opinion, causes hybridstobe ster