michelle-williams-segel.jpgArchive photo from August 2012

Michelle Williams and Jason Segel have split, according to Us Weekly.

The two started dating early last year, and though they kept their relationship under wraps, just last month they were spotted on vacation in Cancun with Williams' BFF Busy Philipps.

So what drove them apart? A source tells the mag they "couldn't survive the long distance," as Segel is based out of Los Angeles and Williams lives in New York with her 7-year-old daughter Matilda.