The mechanism almost certainly evolved, at least in humans, as a way to limit cancer.
This mechanism has evolved through natural selection to ensure that human groups survive.
After years of a state-dominated economy, the mechanisms for private investment, domestic or foreign, are still evolving.
But this mechanism evolved to get through a difficult winter - and we're living now in an eternal spring.
But on the Web, the mechanisms for security and payment are still evolving.
These mechanisms have evolved since the beginning of angiosperms 1000 mya and have become quite effective.
It is not yet known if this mechanism evolved before mosquitoes became the main vectors for transmission of Plasmodium.
This mechanism evolved to keep the young from starving and to ease the burden of raising offspring.
It is possible that this mechanism evolved to protect the mother's health.
It has been proposed that this mechanism evolved to suppress cancer.