Recording-2025-03-12T13:16:44.898Z

Introduction to Primates

• All primates share common traits, but exceptions exist.

• Tree shrews are the closest non-primate genetic relatives but classified under their own order, Scadentia.

Tree Shrew Characteristics

• Classified previously as insectivores, tree shrews exhibit primitive traits compared to modern primates:

  • Long and Wet Nose: Indicates reliance on smell.

  • Long Snout: Suggests adaptation for olfaction.

  • Large Eyes on the Side of the Head: Typical of nocturnal mammals, indicating tree shrews are likely nocturnal.

  • Claws instead of Nails: Differentiates them from primates which generally have nails.

Evolutionary Context

• The divergence between Scandentia and primates occurred a long time ago, with tree shrews retaining some ancestral traits.

• Distinction in physical characteristics:

  • Primates possess front-facing eyes and nails, unlike tree shrews.

  • Primates rely more heavily on vision than olfaction.

Defining Traits of Primates

• A trait list is required to define primates distinctively from other mammals:

  • Small Litter Size: Generally produce one offspring at a time, although some exceptions (e.g., twins).

  • High Parental Investment: Focus on nurturing single offspring due to the demanding nature of raising primate babies.

  • Prolonged Dependency of Young: Offspring stay with parents longer for development and learning.

Exceptions to Primate Traits

• Traits like prolonged dependency and large brains can also be found in other species, such as dolphins.

• Not all primates possess every characteristic; for instance, some New World monkeys exhibit claws instead of nails.