How did the development of the saddle contribute positively to the growth of trans-saharan trade? a. it enabled merchants to cross the desert safely. b. its creation made animals useful for the first time in the trans-saharan caravan trade. c. it increased the speed of the caravan trade. d.it enabled the berbers to dominate the desert.

It enabled the Berbers to dominate the desert.

Explanation:

The Trans-Sahara trade refers to the trade between West African Kingdoms and Arab and Berber Kingdoms on Africa's Mediterranean coast. They mostly traded gold and traveled as far as Persia. They, mostly traveled in the dry deserts with the help of camels.

Gold was exchanged for salt from the Mediterranean. Berbers were mostly found in Morocco and Algeria. Arabs found the uniqueness of Berber merchants who were trained to fight against Spain. Saddles helped the Berber merchants to travel across the Saharan desert in order to carry on the trade. Saddles helped Berber merchants to carry the huge loads of spices and salt in  exchange of gold in the trans Saharan route.

as university of miami psychologists debra lieberman and adam smith pointed out in a recent article in the journal current directions in psychological science, humans have social and psychological mechanisms to deter incest. with very few exceptions, marriages between brothers and sisters and between parents and their children are verboten in every human culture. the primary psychological anti-incest mechanism is the yuck response. even the idea of sex with their mom or dad, bro or sis is upsetting to most people. the psychologist jonathan haidt has found that nearly everyone is repelled by the prospect of brother-sister sex, even in hypothetical situations in which there is no chance of pregnancy).

the biological cost of incest

this raises an interesting question: just what’s so bad about incest? sure, having sex with your dad or your sister seems gross — but why? some anthropologists have argued that incest taboos are learned social conventions. this explanation, however, doesn’t make sense to me as it does not explain the widespread existence of anti-incest mechanisms in creatures ranging from cockroaches to chimpanzees. second, the incest taboo is about as close to a universal law as human moral rules get.

why should mechanisms to avoid incest be so widespread both in nature and across human societies? the answer is simple. the problem with having sex close with relatives is that there is an astonishingly high chance that your offspring will be born with a serious birth defect.