Origins of Primates Lecture

Introduction

• Humble origins of our ancestors.
• Discovery location: Badlands of Wyoming.
• Focus on tiny bones, unlike large dinosaur bones.

Background

• Dinosaurs ruled the Bighorn Basin, dining in lush forests.
• Dinosaurs extinct ~65 million years ago due to comet impact.
• Primate ancestors appeared ~56 million years ago.

Primate Characteristics

• Larger brain size compared to other mammals.
• Forward-facing eyes for 3D vision.
• Developed leaping abilities.
• Grasping hands and feet with nails instead of claws.

Evolutionary Gap

• 10 million years unaccounted for between dinosaur extinction and primate appearance.
• Jonathan Block hunts evidence in Bighorn Basin limestone.

Research Process

• Bones found in limestone examined in the lab.
• Bones coated and treated with acid to expose them.
• Hundreds of tiny bones discovered.
• Mapping and documenting bones to determine their origins.

Discovery of Plesiidaeperforms

• Tiny mouse-like creatures from the period between dinosaurs and primates.
• Over 120 species identified.
• Most complete skeletons known for Plesiidaeperforms.

Primate Evolution Evidence

• Nail structure found in fossils, a primate trait.
• Collaboration with Mary Silcox, Eric Sargis for further study.

Techniques Used

• CAT scanning of primitive skulls.
• Mapping bone relationships, comparing anatomical data.
• Numerical system for data comparison and algorithmic family tree construction.

Findings

• Single family tree indicates Plesiidaeperforms are likely early primates.
• Species Dryomomes identified as a transitional specimen.

Conclusion

• Early primates evolved over 10 million years from small mammals.
• Evolution spurred by dinosaur extinction.
• Co-evolution with flowering plants and fruit led to primate adaptations.
• Without these evolutionary changes, modern humans might not exist.

Implications

• Study reveals insights into primate ancestry and evolutionary history.
• Highlights the significance of mass extinction events on evolution.