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On Human Origins, Smithsonian Teaching Resources Oversell Evolution

Sarah Chaffee

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Recently, I reviewed the Smithsonian Human Origins Project’s Cultural and Religious Teaching Strategies Resource for evolution education. Now, I’d like to delve into some of their other materials in the Teaching Evolution through Human Examples resources. Topics include adaptation to altitude, skin color, malaria, and a unit entitled “What Does It Mean to Be Human?” I will address the first three here today. Unfortunately, regarding the power and effects of evolution, each of them claims more than the evidence demonstrates.

Macroevolution and Microevolution

In the altitude adaptation unit, students learn about icefish and other fish living in frigid waters — called notothenioids. In these fish, an antifreeze protein allows them to survive in waters where the temperature is below that of the freezing point for blood. Students watch a video, “The Making of the Fittest: The Birth and Death of Genes,” and then are asked to answer the question, “How would biologists explain how the antifreeze protein evolved in living icefish from ancestors that did not make the antifreeze protein?” In other words, they are to give a scientific explanation for the emergence of this new protein. However, scientific explanations for the antifreeze protein are based on sequence analysis — what may have happened. But sequence analysis doesn’t address how this would happen. Next, the students address the genetic basis of adaptation to altitude in Tibetans. This section involves interesting some discussion, but there isn’t much evidence that these genetic changes demonstrate macroevolution. If we’re simply talking about an allele shift involving one nucleotide base change, that doesn’t go beyond the known power of natural selection acting on random mutations.

Another unit covers human skin coloration. It notes that skin color is under the influence of many genes, but this doesn’t necessarily show meaningful gain of information. On the other hand, this unit is a near-perfect description of microevolution — down to the description of rock pocket mice and their varying coat colors. Students should definitely learn about microevolution, because it does have applications in medicine and other parts of our lives! But it doesn’t help explain the emergence of humans — which is what the Smithsonian’s Human Origins Project seeks to explore.

The Edge of Evolution

The third unit delves into malaria, one of the leading causes of death in the world. In a description for students of a scientific experiment, it talks about how resistance to the drug chloroquine came about because of a change in an amino acid in the PfCRT protein — lysine changed to threonine. This sounds a lot like what Michael Behe discusses regarding malaria in The Edge of Evolution. Yet, the authors try to use this discussion to build their case for human evolution when in fact malaria demonstrates the opposite: how little evolution can accomplish even in organisms with huge populations and short generation times. The G6PD deficiency shows a loss of information that is beneficial — not the emergence of a new protein or anything similar to that.

The Teaching Evolution Through Human Examples resources present evolution as something it’s not: processes of unguided Darwinian evolution do not explain human origins. If one can appreciate microevolution for what it is and what it shows, there is a lot to learn. And philosophical questions like who we are and where we came from are surely worth considering. But nothing in these documents will bring students closer to being able to do so in an informed manner.

Photo credit: A display at the David H. Koch Hall of Human Origins, Smithsonian’s National Museum of Natural History, by Ryan Somma, via Flickr.