1. Alfred Hitchcock’s “The Birds”
Discussing the Origin of Birds
Suu Suu Zhou, Andy Gomez, Victor Garcia, Mona Moshfegh
AP Biology Period 4

2. Background Information
Birds are descendants of theropod dinosaurs.
Charles Darwin suggested that all species are descended with modification from other species.
Fossils often have features that are intermediate
between those of an ancestral form and its descendants.
These fossils help us understand how different groups
of organisms living today are related.

3. Summary
The origin of birds is a topic of great controversy in the ornitho-paleontological community
Most dinosaurs do not resemble birds, but upon the discovery of the archaeopteryx, the shared features were evident
There are other traits in dinosaurs that are in birds, which shows how birds are descended from the dinosaurs.
Only the more birdlike dinosaurs (theropods) survived the mass extinction
Birds are the modern dinosaurs

4. Species Descend From Other Species
Key Concept:
Species Descend From Other Species
The Archaeopteryx
Archaeopteryx fossils show that both living birds and living reptiles are related.
The distinct birdlike features are clear in the wings, feathers, and digits
Archaeopteryx is an ancestor of birds

5. Shared Anatomical Features
Bones and Traits
Key Concept:
Shared Anatomical Features
Traits of Theropods
Wishbones
Feathers (even if not for flying)
Hollow bones
Anatomical structure

6. Discussion Point 1
-Did birds evolve from dinosaurs? What kind of dinosaurs?
-What similarities do birds have with dinosaurs?

7. Discussion Point 1 (cont.)
-Birds evolved from theropods, which are dinosaurs that have two legs and three toes, as well as hollow bones.
-Dinosaurs and birds share many physical characteristics such as bone structure and feathers

8. Discussion Point 2
In the video, Dr. Clarke says, “It was long assumed that feathers evolved for flight. But clearly, feathers predate flight and arose for some other purpose.”
Why is this significant?
What caused the first feathers to appear?
Why did the feather trait become more common?
Did the feathers let them fly immediately, or did flight take a while to evolve?

9. Discussion Point 2 (cont.)
Feathers were not developed solely for flight
Mutation (a random process) caused the first feathers to appear
Feathers might be beneficial for insulation or communication
Flight was not immediate and the feathers gained use over time
-the beginnings of feathers were the

10. Review Questions ON YOUR PAPER, WRITE THE ANSWER!~
What caused the first feathers to appear?
Does having feathers mean you can fly?
What traits does the T-Rex share with the chicken?🐓

11. ANSWERS Mutations Not necessarily
Anatomical structures, such as Wishbones and Hollow bones

12. Thanks for listening!