Question

1. (4m) While mating, the male redback spider does a somersault so that the back of his abdomen dangles directly over the jaws of the much larger female. This entices the female redback spider to begin to eat the male’s abdomen but does not affect the continuing transfer of sperm.

Propose two possible explanations for the male’s behavior. One explanation should deal with ultimate causation; the other explanation should deal with proximate causation.

Answer 1

• The male redback spider have a self sacrificing nature during the reproduction, by this nature the male can increase the length of copulation, as a result large number of sperm get transfered into the female redback spider.
• This self sacrificing nature is an innate and genetically programmed behavior.
• By this nature the male provide nutrients to his hungry partner. Because the female eat the males abdomen.

2.

• The male redback spider is smaller than females, for transfering sperm into females sperm storage organ, it insert pedipalp into female and it turn its body to 180 degree, as a result abdomen becomes dirctly infront of females jaws, the male performs somersault.
• By this male provide male provide nutrients to its offsprings. This hepls in fertilizing large number of eggs.