Which observations led Darwin to establish a relationship between extinct and living animals? Select all that apply. Select all that apply. A. Tortoises from different Galapagos islands have distinct shells. B. Birdwing butterflies were found throughout the Malay archipelago, but species differed slightly from island to island. C. The fossilized remains of giant sloths were found in places where smaller sloths now live. D. Bird families clustered geographically: cockatoos in the Malay Archipelago and Australia, macaws and hummingbirds in the Americas. E. Mockingbirds from different Galapagos islands had subtle, consistent differences. F. The bony shells of armadillos resembled the shells of ancient Glyptodon fossils.