Recitation Week 2 - Evolution & Natural Selection (1/24-25)

This week in recitation we reviewed the first and second lectures of the semester, presented by Dr. David Ehrenfeld.  In this post, I will briefly outline some of the terminology and concepts we discussed.  This post will not substitute your personal notes, but will highlight some key terms and concepts.  Therefore, specific research examples from lecture, or from your readings are not discussed below. I've included hyperlinks to expand upon lectures and the assigned readings; with an emphasis on resources with informative visual aids.

Lectures 1-2 - Evolution & Natural Selection

Important Figures:

  Charles Darwin (Origin of Species, 1859)

  Alfred Russell Wallace 

Biological Species Concept (BSC)

Speciation (this hyperlink has a lot of great visuals)

Allopatric speciation                                          

Peripatric speciation ("founder effect")

  Allopatric speciation (geographic isolation) 

Sympatric Speciation 

Sympatric speciation

   Parapatric speciation

Natural Selection & Speciation

Convergent Evolution

 Adaptive Radiation & Galapagos finches

News article: fossils, DNA, frogs, & teeth!

The tree frog in question (Wikimedia commons)

A student forwarded me this interesting New York Times article about a frog species that has evolved to have teeth on its lower jaw.  This trait, lost at least 230 million years ago (MYA) in frogs, appears to have reemerged approximately 5-17 MYA in a marsupial tree frog.  

Read The Times article highlighting this research: A Frog Evolved to Regain the Teeth Its Ancestors Jettisoned.

Or better yet, go to the source article by Dr. Weins! Re-evolution of lost mandibular teeth in frogs after more than 200 million years, and re-evaluating Dollo's law.

This research was originally published in the peer-reviewed scientific Journal Evolution by John J. Weins (2011).  The full article includes figures with phylogenetic trees illustrating relatedness among species based on genetic DNA results and teeth presence/absence.