Evolution: Education and Outreach

by McCall, Lauren W.

While human genetic variation is limited due to a bottleneck on the origin of the species ∼200 kya, cultural traits can change more rapidly, and may do so in response to the variation in human habitats. Does cultural diversification simulate a natural experiment in evolution much like biodiversity so that cultural divergences and convergences can be interpreted in terms of the differences and similarities of local environments? Or is cultural diversity simply the result of human behavioral flexibility? Although the majority of cultural data comes from the tips of the hominin phylogeny, anthropologists can follow the example of evolutionary ecologists, who often compare the endpoints of phylogenies when that is all that is available. This article compares 97 contemporary indigenous language communities from around the world, and 24 of their cultural traditions, to help determine whether human cultures and their cultural traits are proportionately dispersed, as predicted by the neutral theory of biodiversity, or whether they show non-proportionalities that could be explained with evolutionary reasoning.

DOI: 10.1007/s12052-008-0067-2
Online Date: 10/31/2008
Print publication date: 3/1/2009
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by Moore, Randy; Cotner, Sehoya

College students whose recollections of their high school biology courses included creationism were significantly more likely to invoke creationism-based answers on questions derived from the Material Acceptance of the Theory of Evolution (MATE) instrument than were students whose recollections of their high school biology courses included evolution but not creationism. On average, students who were taught neither evolution nor creationism in their high school biology courses exhibited intermediary responses on the MATE instrument. These results suggest that (1) high school teachers’ treatments of evolution and creationism have a lasting impact and (2) the inclusion of creationism in high school biology courses increases the probability that students accept creationism and reject evolution when they arrive at college. These results are discussed relative to the impact of high school biology courses on students’ subsequent acceptance of evolution and creationism.

DOI: 10.1007/s12052-008-0097-9
Online Date: 10/25/2008
Print publication date: 3/1/2009
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by Novella, Steven

The human eye is an excellent example of suboptimal bottom-up design resulting from the constraints of evolutionary historical contingency. The resulting suboptimal optics manifests in a number of medical ophthalmological disorders.

DOI: 10.1007/s12052-008-0092-1
Online Date: 10/25/2008
Print publication date: 10/1/2008
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by Espinasa, Monika; Espinasa, Luis

When we teach evolution to our students, we tend to focus on “constructive” evolution, the processes which lead to the development of novel or modified structures. Most biology students are familiar with the subjects of finches’ beaks, giraffes’ necks, and hair in mammals. Of course, there is nothing inherently wrong with a constructivist approach to teaching evolution, but if it is our only focus, we may overlook the flip side of the coin. By the flip side of the coin, of course, we are referring to regressive evolution: the loss or degeneration of a trait. Regressive evolution does not often make its way into biology textbooks, but it is of great relevance nonetheless. In all likelihood, when a new trait evolves or an existing one is modified, something is sacrificed in return. In order to develop a flipper, a marine mammal must sacrifice individual digits. You may be familiar with one or more of the following familiar characters lost through regressive evolution: teeth in birds, scales in mammals, and tails in higher primates. For aficionados of cave biology like us, one of the most interesting examples of regressive evolution concerns cave fish: Why do cave fish lose their eyes?

DOI: 10.1007/s12052-008-0094-z
Online Date: 10/23/2008
Print publication date: 10/1/2008
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by Oakley, Todd H.; Pankey, M. Sabrina

Eyes provide a rich narrative for understanding evolution, having attracted the attention of preeminent scientists and communicators alike. Until recently, this narrative has focused primarily on the evolution of eye structure and far less on biochemistry or genetics. Although eye biochemistry was once likened to an unknown “black box;” the flood of discoveries in biochemistry is now allowing an increasingly detailed understanding of the processes involved in vision. As a result, evolutionary comparative (“tree-thinking”) analyses that use these data currently allow a new and still unfolding narrative, both richer in detail and more comprehensive in scope. Rather than toppling evolutionary theory by finding irreducibly complex molecular machines, eye evolution provides detailed accounts of how natural processes tinker with existing genetic components, duplicating and recombining them, to yield complex, intricate, and highly functional eyes. Understanding the new biochemical narrative is critical for researchers and teachers alike, in order to answer anti-evolutionist claims, and to provide an up-to-date account of the state of knowledge on the subject of eye evolution.

DOI: 10.1007/s12052-008-0090-3
Online Date: 10/23/2008
Print publication date: 10/1/2008
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by Eldredge, Gregory; Eldredge, Niles

DOI: 10.1007/s12052-008-0081-4
Online Date: 10/21/2008
Print publication date: 10/1/2008
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by Buschbeck, Elke K.; Friedrich, Markus

The visual organs of insects are known for their impressive evolutionary conservation. Compound eyes built from ommatidia with four cone cells are now accepted to date back to the last common ancestor of insects and crustaceans. In species as different as fruit flies and tadpole shrimps, the stepwise cellular patterning steps of the early compound eye exhibit detailed similarities implying 500 million years of developmental conservation. Strikingly, there is also a cryptic diversity of insect visual organs, which gives proof to evolution’s versatility in molding even the most tenacious structures into something new. We explore this fascinating aspect in regard to the structure and function of a variety of different insect eyes. This includes work on the unique compound–single-chamber combination eye of twisted-winged insects and the bizarre evolutionary trajectories of specialized larval eyes in endopterygote insects.

DOI: 10.1007/s12052-008-0086-z
Online Date: 10/18/2008
Print publication date: 10/1/2008
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by Young, Gavin C.

Evidence of detailed brain morphology is illustrated and described for 400-million-year-old fossil skulls and braincases of early vertebrates (placoderm fishes). Their significance is summarized in the context of the historical development of knowledge of vertebrate anatomy, both before and since the time of Charles Darwin. These ancient extinct fishes show a unique type of preservation of the cartilaginous braincase and demonstrate a combination of characters unknown in other vertebrate species, living or extinct. The structure of the oldest detailed fossil evidence for the vertebrate eye and brain indicates a legacy from an ancestral segmented animal, in which the braincase is still partly subdivided, and the arrangement of nerves and muscles controlling eye movement was intermediate between the living jawless and jawed vertebrate groups. With their unique structure, these placoderms fill a gap in vertebrate morphology and also in the vertebrate fossil record. Like many other vertebrate fossils elucidated since Darwin’s time, they are key examples of the transitional forms that he predicted, showing combinations of characters that have never been observed together in living species.

DOI: 10.1007/s12052-008-0087-y
Online Date: 10/18/2008
Print publication date: 10/1/2008
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by Zimmer, Carl

DOI: 10.1007/s12052-008-0089-9
Online Date: 10/16/2008
Print publication date: 10/1/2008
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by Oakley, Todd H.

DOI: 10.1007/s12052-008-0093-0
Online Date: 10/16/2008
Print publication date: 10/1/2008
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