The Mystery Behind the Biggest Bears of All Time

PBS Eons・2 minutes read

The spectacled bear in South America is distinct for its looks and diet, descended from extinct bears, adapting to changes in environment and competition through evolution. It is the sole surviving bear species in South America after the disappearance of its larger ancestors in North America, with genetic evidence linking it closer to Arctotherium angustidens rather than North American giant bears.

Insights

  • The spectacled bear is the only remaining native bear in South America, distinguished by its unique appearance and primarily plant-based diet.
  • Genetic evidence indicates that the spectacled bear shares a closer relationship with Arctotherium bears from South America than with giant bears from North America, suggesting a complex evolutionary history shaped by environmental changes and competition.

Get key ideas from YouTube videos. It’s free

Recent questions

  • What is the spectacled bear known for?

    Unique appearance and plant-based diet

  • What is the relationship between the spectacled bear and extinct short-faced bears?

    Last surviving member, related to extinct short-faced bears

  • How did bears migrate to South America?

    Great American Biotic Interchange

  • What caused the evolution of smaller, herbivorous bears in South America?

    Increased competition, adaptation to changing environment

  • What led to the disappearance of giant bears in North America?

    Mystery, leaving spectacled bear as only surviving species

Related videos

Summary

00:00

Evolution and Mystery of South American Bears

  • The spectacled bear is the only native bear in South America, known for its unique appearance and plant-based diet.
  • The spectacled bear is the last surviving member of the Tremarctinae subfamily, related to extinct short-faced bears.
  • Ancestors of the spectacled bear included enormous bears like Arctodus simus and Arctotherium angustidens.
  • The Great American Biotic Interchange led to the migration of bears from North America to South America.
  • Genetic evidence suggests that Arctotherium is more closely related to the spectacled bear than to North American giant bears.
  • Arctotherium angustidens was likely an omnivore, adapting to a changing environment in South America.
  • Arctotherium bears evolved to be smaller and more herbivorous over time, possibly due to increased competition.
  • Arctodus simus, a giant bear in North America, may have been a scavenger rather than a hypercarnivore.
  • The disappearance of Arctodus simus and Arctotherium angustidens remains a mystery, leaving the spectacled bear as the only surviving species.
Channel avatarChannel avatarChannel avatarChannel avatarChannel avatar

Try it yourself — It’s free.