Tag Archives: Evolution

Darwin, Wallace, and Natural Selection – A Short Film

Below is an HHMI BioInteractive short film on the epic voyages of Darwin and Wallace that led each to independently discover the natural origin of species and to formulate the theory of evolution by natural selection.

Many textbooks are smothered with Charles Darwin as being the “father” of natural selection,  rarely mentioning Alfred Wallace at all. In scientific circles, both men are credited with arriving at natural selection theory independently.

It is important to note that their theories were not entirely identical. Darwin’s theory is more focused on individual struggle while Wallace’s tends to concern itself with populations and groups. Wallace possessed more combined field time than Darwin, and in my opinion, Wallace explored more smaller isolated lands than Darwin which led to the Wallace Line – an imaginary boundary line separating ecozones that explains the differentiation of species among groups.

Wallace Line
Wallace Line

There is a richer backstory to both Darwin and Wallace, but to end this blog post, be comforted in knowing that they remained friends, despite minor disagreements. For example, Darwin believed that animal breeding could demonstrate natural selection, but Wallace always disagreed, arguing that such demonstrations are examples of artificial selection rather than natural selection (Wallace was correct). The short film below highlights how both men arrived at their theories.

Evolution of the Eyes

Millions of years ago, the first eyes calmly yawned at the sun’s light that massaged the earth. These primitive eyes did very little but detect light that helped organisms to establish day/night cycles and allowed them to coordinate behavior. Throughout time, eyes became more complex as organisms evolved more complex bodies and behaviors. This led to a gradual series of fine-tuned focusing muscles, better optics, and morphological changes that provide a survival advantage to animals in detecting prey – or predator.

Below are some resources and videos regarding the evolution of the eyes.

This video, “Eyes,” is part of the “Evolve” History Channel 11-part series that looks at the evolutionary origins of a particular trait. “Eyes” is the evolutionary story of how the eye was molded into the exquisite complicated organ we see today.

 

Here’s a TED-Ed animated story on “The Evolution of the Human Eye” by Joshua Harvey.

 

“To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I confess, absurd in the highest degree…The difficulty of believing that a perfect and complex eye could be formed by natural selection , though insuperable by our imagination, should not be considered subversive of the theory.” –Charles Darwin

 

This is a one hour academic lecture “The Evolution of Vision” lectured by Dr. William Ayliffe at Gresham College in 2012.  Although not cinematically crafted as other videos, this dense in-depth lecture has interesting bits ranging from Darwin’s personal diary notes to modern genetic research on eyes. Powerpoints, transcripts, and links to other videos in Dr. Ayliffe’s series (Vision and the Artist, The Aging Eye, The Window on the Soul, Animal Eyes, etc.) can be found here.

 

A young Richard Dawkins brilliantly demonstrates the evolution of the eye in this 14 min video. This was part of the 1991 Christmas Lectures.

 

Fast forward in time, a late Richard Dawkins explains the evolution of the eye in this 2010 video.

 

This is a video excerpt from a 2002 series “Evolution” concerning the evolution of the eye. It is narrated by Liam Neeson. Yes, he will find you and he will eye you.

 

A Ted-X talk by the author of “Evolution’s Witness: How Eyes Evolved.”

 

This is a short video from BBC’s Course Clips.

 

Evolution of the Eye, an infographic created by Voltier Creative via Zmescience.

Further reading:

  • http://learn.genetics.utah.edu/content/selection/eye/
  • http://www.nyas.org/publications/detail.aspx?cid=93b487b2-153a-4630-9fb2-5679a061fff7
  • http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3143066/
  • http://evolution.berkeley.edu/evolibrary/article/eyes_01
  • http://www.scientificamerican.com/slideshow/lamb-evolutions-eyes-slide-show/
  • http://physics.okstate.edu/axie/courses/4313/2012fall/C7_B2_reading-evolution-of-eye-2011.pdf
  • http://www.d.umn.edu/~olse0176/Evolution/mammals.html
  • http://www.nick-lane.net/Darwin%20and%20the%20Eye.pdf
  • http://www.evodevojournal.com/content/4/1/26
  • http://rstb.royalsocietypublishing.org/content/364/1531/2833