Demise of the Great Beasts

Description
A jubilant cheer goes up from your tribesmen as the giant, savage creature finally succumbs to the blows, and topples to the ground with a thunderous crash. Dead. You share your kin's rejoicing -- the kill promises plenty of meat -- but your happiness is tinged with sadness too. These great beasts cross the tribe's path less and less often these days, no doubt hunted to death by the most skillful hunters of all -- humans. Their eventual disappearance seems certain. What steps will you take to ease the burden of their loss?

Options
"We will understand the ebb and flow of the seasons on our foraged foods, so that they may give us greater bounties in time."
 * Study
 * Effect: Modify Calendar research cost by -25%

"Mammoths might never be subdued, but perhaps other animals can be bent to our will, so we never need starve."
 * Tame
 * Effect: Modify Domestication research cost by -25%