It’s hard to believe that ‘KUWTK’ is already in its 16th season, and things sure have changed since the show began in 2007 — including how the cast members look!

The Kardashian family members have changed up their looks plenty of times over the years, but it’s still pretty shocking to see just how much they’ve transformed since the first season of Keeping Up With the Kardashians. Ahead of the show’s season 16 premiere on March 31, we’re looking back at how drastically the fam has changed. Of course, Kendall Jenner and Kylie Jenner underwent the biggest transformations. After all, they were just 11 and nine years old, respectively, when the show first premiered, Now, they’re grown women!

Kendall, who is now 23, transformed from an awkward pre-teen to one of the world’s hottest supermodels in the years since KUWTK began. Along with her growth spurt, Kendall also grew into all her features, and almost looks like a different person. Meanwhile, Kylie, who’s 21, went from a child to a mother in the last 12 years. Although she doesn’t plump up her lips as much as she did in her late teen years, her bigger pout is definitely one of the most drastic differences in her features from season one until now.

It might be Caitlyn Jenner who underwent the biggest transformation of all, though — remember, she was still Bruce Jenner when KUWTK premiered! Caitlyn’s transition into a woman remains one of the most iconic storylines the show has ever had, and although she only appears on KUWTK very rarely these days, she obviously looks much different.

Kim Kardashian, Kourtney Kardashian, Khloe Kardashian, Kris Jenner, Scott Disick and Rob Kardashian have also transformed in big ways since the start of their family’s fame. Click through the gallery above to check out the before and after photos, and tune into KUWTK on March 31 at 9:00 p.m. on E!