This worksheet was created during the Covid-19 pandemic to be administered remotely on google classroom. The student version is available for free through google docs, which also can be copied for students in Google Classroom.
The activity is adapted from Understanding Evolution: which outlines mechanisms for how snakes evolved from lizards. It was designed for second year (AP Biology) biology students and has fairly detailed and advanced concepts to work through.
This download includes the answer key and a pdf version of the student document, I recommend using the link to download the google doc version of the worksheet for editing and sharing with your students.