Week 9 Lecture Notes: Primate Origins and Evolution

Course Progress Update

• We're in Week 9 of a 16-week semester.
• Entering the final part of Module 2.
• Exam 2 scheduled for November 7th.

Readings and Learning Objectives

• Readings: Chapter 8 from "Explorations."
  • Chapter is dense and requires time management (suggest breaking into sessions).
• Learning Objectives:
  • Understand climate evolution from primates to human species.
  • Learn about primate adaptations and major groups.
  • Discuss evidence used by primatologists to relate extinct and living primates.
  • Recognize geographical and climatic influence on primate distribution.
• Important Taxonomic Groups:
  • Plesiadapiforms, Carpolestes, Adapoids, Omomayids, and others.

Videos and Assignments

• Videos:
  • "Evolution in Reverse," "Floating Island in Panama," "Evidence for Evolution."
• Discussion Assignment: Scientist Spotlight
  • Choose a scientist and discuss their contributions.

Primate Origins

• Hypotheses on Primate Evolution:
  • Arboreal Hypothesis: Adaptations to tree life (vision, limb flexibility).
  • Visual Predation Hypothesis: Forward-facing eyes relate to predatory behavior.
  • Angiosperm Coevolution Hypothesis: Adaptations linked to fruit-bearing plants.

Primate Taxonomy

• Strepsirrhines vs. Haplorhines:
  • Strepsirrhines: Lemurs, lorises.
  • Haplorhines: Tarsiers, monkeys, apes.
• Characteristics differ in snout length, eye orbit closure, and vision.

Early Primate Evolution

• Eocene Primates (50-55 million years ago):
  • Adapoids: Long snout, small eyes (diurnal).
  • Omomayids: Short snout, large eyes (nocturnal).
• Fossils:
  • Notharctus: Similar to modern lemurs.
  • Ida (Darwinius masillae): Well-preserved fossil from Germany with opposable toe and evidence of fruit diet.

Key Takeaways

• Understanding primate evolution helps contextualize biological adaptations.
• Fossil records provide insight into primate and human ancestry.
• Study of various hypotheses gives a comprehensive view of primate adaptations and behaviors.