How Evolution Works, Part 2
(Video #7 in the BioLogos Basics video series.) In the previous video we looked at microevolution—small changes in a population on relatively short timescales. Most critics of evolution accept this but are skeptical of macroevolution—the claim that small changes can add up to big changes over long stretches of time.
Next Steps for Exploring this Topic:
- Evidence for Evolution. Two posts in this blog series give further details about whale evolution from the perspectives of DNA and comparative anatomy.
- Understanding Evolution: Theory, Prediction, and Converging Lines of Evidence This blog series by Fellow Dennis Venema uses whale evolution as the example to explain evolution.
- What is Evolution? Our common question entry on the topic, with many more resources.
- Common Ancestry In this short video clip, Denis Alexander explains how he understands human common ancestry with other life forms as “very good”.
- Does Science Disprove Faith? Video of a sermon by John Ortberg, which addresses science in general, but also evolution in particular.
- Finally, consider several blog posts from 2012 by our former Senior Fellow of Arts and Humanities, Mark Sprinkle. These are artistic representations of whales, including a poem, a sculpture, and a song.
Script for “How Evolution Works - Part 2":
In the previous video we looked at microevolution—small changes in a population on relatively short timescales. Most critics of evolution accept this but are skeptical of macroevolution—the claim that small changes can add up to big changes over long stretches of time. While the particulars of the mechanisms for such change are not all fully understood, there is very little disagreement among biologists that we now have powerful models of macroevolutionary transitions. These models make testable predictions and are continuously being refined by new evidence.
Whales provide a clear example of macroevolution. They are superficially similar to fish, but are, in fact, mammals! Darwin himself wondered whether whales had evolved from mammals on land, but he had no real empirical evidence for such a claim. Now we have impressive evidence.
In 1978 a 49 million year old skull was discovered that belonged to a land-dwelling wolf-like creature whose inner ear structure was curiously similar to that of modern whales. This led to a search for transitional forms, and very quickly a series of fossils spanning about ten million years was found that showed clear signs of increasing adaptation to life in water. The spine and legs were modified to allow for more efficient modes of swimming; nostrils moved toward the top of the skull, later becoming a blow hole; and hind legs eventually shrank to where they could no longer support the animals on land.
Many more fossils fit into this picture of whale evolution—more than 1000 specimens have been discovered in the Valley of Whales in what is now Egyptian desert. Remember these are not necessarily direct ancestors of whales today. That’s not how evolution works. More likely is that these represent related species that were evolving over millions of years. And taken together, they form an impressive picture of significant change in this lineage of mammals. This picture is not the result of wishful thinking or driven by unwarranted assumptions. It has emerged as the result of careful observation of evidence, which leads to the formation of hypotheses; these make predictions of future finds and are tested by observable evidence which is open to the scrutiny of others.
At BioLogos we see this interconnectedness of life as a testimony to God’s creativity. He worked through simple natural processes to fashion dinosaurs and daisies, weevils and warthogs, and human beings in his own image. He could have snapped his fingers to do this instantaneously, but both scripture and the natural world reveal that God delights in working through processes to accomplish his will. Evidence from the fossil record and also in the distribution and comparison of species supports the claim that he worked through evolution. And today we find even more persuasive evidence in genetics. We’ll consider that in our next video.
Script: Jim Stump
Video Production: Andrew DeSelm
Narrator: Chris Stump