I need your help

I will be in Washington DC this coming weekend, and I would like to visit the Smithsonian Institute to take pictures of the evidence for evolution.

I am aware of "The Evolution Trail" that will tell me why they believe giraffes have long necks and why they think flowers have many colors. I am also aware of "The Evolution of Evolution" display which has "Specimens from the Museum’s diverse collections, along with documentation from our ongoing research." But I want to find empirical evidence for