Darrin Lowery
- Darrin Lowery found a collection of tools in Maryland that may date to 22,000 years ago.
- That would mean humans first arrived in North America thousands of years before we thought.
- Most experts believe humans first arrived in North America between 15,000 and 20,000 years ago.
North and South America were the last inhabited continents that modern humans settled thousands of years ago, but when and how they reached the Americas remains a mystery.