In today’s Discovery: Mysterious human remains in the Amazon, facial reconstruction from 4,500-year-old DNA, and ticks taking over city parks. 

But first: A last glimpse inside the world’s vanishing cave societies.

For centuries, humans have lived underground. Today, that ancient practice is under dire threat—even as cave life makes more sense than ever.

More stories:
— The Alps’ magical ice caves risk vanishing in our warming world
— How uncharted caves in Greenland could predict the Earth's future

The Mississippi River is in crisis: Recent years have seen severe, months-long droughts take hold across America’s Midwest and South, regularly leaving the river at a historic low. Tons of grains and crops are shipped down the Mississippi River every year. What will happen if America’s longest river runs dry?

BEFORE YOU GO: Looking to capture some great photos for Fourth of July? Here are tips on how to photograph fireworks for that perfect shot.

Today’s newsletter was edited and curated by Jennifer Baik and produced by Alisher Egamov. Did someone forward this to you? Sign up for our other newsletters here.