BIO 181 Lecture 2.6

Lecture 2.6: Evidence for Evolution


In the past, the Earth supported a variety of interesting creatures that are quite different than anything alive today: carnivores–dog- or cat-like creatures–that had hooves like a deer; a little racoon-like critter that also had hooves; a large mammal shaped like a crocodile, which had hooves. Oddly, all of these creatures had ear bones and other features unique to whales and dolphins. Modern organisms also have a variety of odd characteristics: whales have hind limb bones but no hind limbs; they develop hair and whiskers as fetuses but then lose them before birth; you have broken versions of genes from other species in your DNA. In this lecture, we observe these and other strange patterns and discuss why they exist. This discussion leads us to one of the most useful and successful theories–as professional scientists, not the general public uses that term–in all of science.


  1. Download Lec 2.6 slides.
  2. Do one of the following:
    1. In-person section: Attend Lecture 2.6.
    2. Online section: Watch the following videos:
      1. Video 2.6.1, Synapomorphies.
      2. Video 2.6.2, Vestiges.
      3. Video 2.6.3, Molecular evidence for evolution.
  3. Read Sections 22.1 and 22.2 of the textbook.
  4. Complete the questions on Study Guide 2.6.


After completing the activities, log into Canvas, launch BIO 181 and complete Lecture 2.6 Quiz.

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