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Friday, May 22, 2009

Teaching Evolution in Natural History Museums

In an article published last November in Trends in Ecology & Evolution, Bruce MacFadden urges that natural history museums explore the use of new displays, such as those involving genomics and molecular biology, to educate the general public [Evolution, museums and society].

He writes ...
Public understanding of evolution has changed little over the past quarter-century [4]. The challenge therefore remains for natural history museums to improve communication about evolution, particularly the more difficult concepts.
MacFadden notes that museum visitors are more likely to accept evolution. Museums need to do a better job of taking advantage of this fact in order to enhance understanding of evolution.
Evolution represents a complex array of concepts, some of which are well understood whereas others are poorly understood by museum visitors. If an institution is committed to improving public understanding about evolution, then additional resources and effort should be directed toward more effectively communicating the more poorly understood concepts such as natural selection.
Yes, natural selection is difficult but random genetic drift is even more difficult. Unfortunately, I don't get the impression that MacFadden is counting random genetic drift as one of the basic concepts that museum visitors need to learn about.

One solution is to create displays about molecular evolution.
In this regard, there is much room to highlight research traditionally not considered to be natural history, such as genomics and molecular biology [9], although these subjects are not usually specimen based and therefore potentially less attractive to the public. In these instances, visitors are more likely to grasp difficult concepts when they have some prior understanding of a topic [10], or can place these concepts in a modern-day societal context. For example, disease vectors such as influenza and malaria mutate rapidly to become drug resistant, and therefore have negative consequences for world health.
This is a good idea. I recently visited the American Natural History Museum in New York and it had an excellent display on molecular evolution. It showed how you could compare DNA sequences and it explained that many of the mutations were just accidents that became fixed in the population by genetic drift. It even mentioned junk DNA and messy genomes.

It was a very popular display. Not only did it highlight some of the most important evidence for the history of life, it also explained the two main mechanisms of evolution. There were more people reading the material in the molecular evolution area than in the more traditional fossil areas. DNA is exciting.

Kotiaho et al. (2009) disagree. In the June issue of Trends in Ecology & Evolution they write [Evolution education in natural history museums ] ...
In his essay, MacFadden advocates the allocation of resources into novel contents, such as genomics or molecular biology, in order to increase the public understanding of evolution. We argue that museums should concentrate more on demonstrating the basic principles and outcomes of natural selection, rather than presenting fashionable novel contents such as genomics (which, it seems, even scientists often have a hard time understanding [4]).
It's clear that Kotaiho et al. see natural selection as the main (only?) mechanism of evolution. What they want is the kind of display that illustrates natural selection. They like dioramas.
If we want to educate the visitors of natural history museums about evolution by means of natural selection, we should aim at delivering the message that across species there is enormous within-species variation, that some of this variation is likely to cause differences among individuals in their lifetime reproductive success and that these differences will result in a constant change – evolution. In museums, we have a great opportunity to do this; as well as the exhibits open to the public, museums usually have extensive collections containing numerous individuals of each species. A simple illustration of the replacement of one generation by the next generation might work in making the operation of natural selection more tangible. With such an illustration, we can easily see why and how a population can undergo constant change, and thus grasp the basic principles of evolution by means of natural selection.

Natural history museums are our collective memory of the past. Their collections can, and have been, used to study evolution (e.g. [7]). Perhaps even more importantly, however, they could also be used to illustrate to the general public the evolutionary changes that have taken place. We challenge the exhibit designers of natural history museums to emphasize variation within species, and to demonstrate change due to natural selection, rather than stasis in nature.
Here's the problem. It might be fine to mount a display showing variation within a population. It might be possible to construct a display where the next generation has a different degree of variation. But it would be wrong to attribute that to natural selection unless you could present evidence that there were fitness differences associated with those variants.

I fear that these authors are not distinguishing between evolution and natural selection. They think that evidence of evolution is evidence of natural selection.

I don't understand why Kotaiho et al. would want to ignore molecular evolution and genomics. There's no better way to illustrate random genetic drift and there's no excuse for eliminating one of the most important fields in modern evolutionary biology.

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