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A Whale of a Tale?

The Evidence for the Evolution of Whales


Author(s)

Gabriel D. McNett
Department of Biology and Environmental Science
Westminster College
gabe.mcnett@westminster-mo.edu

Abstract

For years whale evolution was characterized by speculation and limited evidence. Evolution critics even focused on whales as a means to criticize evolutionary theory. Now whale evolution represents one of the best examples of "macroevolution." This "clicker case" uses this fascinating story of historical irony as a backdrop to the study of whale evolution. First, students study an array of whale fossils to learn how evolution is properly viewed as a branching, relationship-based process, not a linear, progressive, "chain-of-being." Using this view they learn how scientists seek to reconstruct past relationships and study transitional features, not search for "missing links." Students then learn that evidence for macroevolution relies on several lines of independent evidence from fossils, comparative anatomy, embryology, genetics, and paleoecology. With a focus on macroevolution, this case makes a critical contribution to evolution education. It could work well in a lower level undergraduate biology / evolution / paleontology course (non-majors or majors), or in an upper-level evolution course, perhaps early in the semester as a primer for related topics.


Objectives

  • Distinguish evolution as a branching, relationship-based process, rather than a linear, progressive process.
  • Interpret the basic structure of an evolutionary (phylogenetic) tree.
  • Discuss various independent lines of evidence that support the evolution of whales from a four-legged, terrestrial vertebrate.

Keywords

Macroevolution; phylogenetics; cetaceans; missing link; fossils; transitional forms; whales; dolphins; Cetaceans; Pakicetus; Ambulocetus

Topical Areas

N/A

Educational Level

High school, Undergraduate lower division, Undergraduate upper division

Format

PDF

Type / Methods

Clicker

Language

English

Subject Headings

Biology (General)  |   Paleontology  |   Evolutionary Biology  |  


Date Posted

12/23/2015

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