Communicating Phylogeny: Evolutionary Tree Diagrams in Museums

Tree of life diagrams are graphic representations of phylogeny—the evolutionary history and relationships of lineages—and as such these graphics have the potential to convey key evolutionary ideas and principles to a variety of audiences. Museums play a significant role in teaching about evolution to the public, and tree graphics form a common element in many exhibits even though little is known about their impact on visitor understanding. How phylogenies are depicted and used in informal science settings impacts their accessibility and effectiveness in communicating about evolution to visitors. In this paper, we summarize the analysis of 185 tree of life graphics collected from museum exhibits at 52 institutions and highlight some potential implications of how trees are presented that may support or hinder visitors’ understanding about evolution. While further work is needed, existing learning research suggests that common elements among the diversity of museum trees such as the inclusion of anagenesis and absence of time and shared characters might represent potential barriers to visitor understanding.     

Talking About Evolution in Natural History Museums

The Natural History Museum’s approach to conducting learning conversations about evolution with visitors in the galleries is described. Potentially difficult scenarios were identified, and training was developed for education staff and volunteers to enable them to engage visitors with a range of motivations and beliefs. Workshops and discussion events focusing on evolution, which form part of the museum’s education program, are also described.     

The Fossil Record of Feather Evolution in the Mesozoic

The oldest known feathers from the Late Jurassic are alreadymodern in form and microscopic detail. Because these oldestexamples are assignable to an extinct branch (Sauriurae) ofthe basal avian dichotomy, their features must have been establishedat a significantly earlier date. The skin of a wide varietyof dinosaurs is now known and is unlikely to represent a predecessorto a feather bearing integument. Examples of feathered dinosaursresult from erroneous identification of internal structuresas part of the skin covering, and from the confusion of flightlessbirds from the Early Cretaceous of China with dinosaurs.     

Dental Eruption Sequences in Fossil Colobines and the Evolution of Primate Life Histories

Unlike other catarrhines, colobines show early molar eruption relative to that of the anterior dentition. The pattern is variable, with Asian genera (Presbytina) showing a greater variability than the African genera (Colobina). The polarity of early relative molar eruption, as well as the degree to which it is related to phylogeny, are unclear. Schultz (1935) suggested that the trend reflects phylogeny and is primitive for catarrhines. More recently, however, researchers have proposed that life history and dietary hypotheses account for early relative molar eruption. If the colobine eruption pattern is primitive for catarrhines, it implies that cercopithecines and hominoids converged on delayed relative molar eruption. Alternatively, if the colobine condition is derived, factors such as diet and mortality patterns probably shaped colobine eruption patterns. Here we update our knowledge on eruption sequences of living colobines, and explore the evolutionary history of the colobine dental eruption pattern by examining fossil colobine taxa from Eurasia (Mesopithecus) and Africa (Kuseracolobus aramisi and Colobus sp.) and the basal cercopithecoid Victoriapithecus macinnesi. We scored specimens per Harvati (2000). The Late Miocene-Early Pliocene Mesopithecus erupts the second molar early relative to the incisors, while the Early Pliocene Kuseracolobus aramisi does not. These results demonstrate that the common colobine tendency for early molar eruption relative to the anterior dentition had appeared by the Late Miocene, and that some of the diversity observed among living colobines was already established in the Late Miocene/Early Pliocene. We discuss the implications of these results for phylogenetic, life history, and dietary hypotheses of dental development.     

Convergent Evolution in Aquatic Tetrapods: Insights from an Exceptional Fossil Mosasaur

Mosasaurs (family Mosasauridae) are a diverse group of secondarily aquatic lizards that radiated into marine environments during the Late Cretaceous (98–65 million years ago). For the most part, they have been considered to be simple anguilliform swimmers – i.e., their propulsive force was generated by means of lateral undulations incorporating the greater part of the body – with unremarkable, dorsoventrally narrow tails and long, lizard-like bodies. Convergence with the specialized fusiform body shape and inferred carangiform locomotory style (in which only a portion of the posterior body participates in the thrust-producing flexure) of ichthyosaurs and metriorhynchid crocodyliform reptiles, along with cetaceans, has so far only been recognized in Plotosaurus, the most highly derived member of the Mosasauridae. Here we report on an exceptionally complete specimen (LACM 128319) of the moderately derived genus Platecarpus that preserves soft tissues and anatomical details (e.g., large portions of integument, a partial body outline, putative skin color markings, a downturned tail, branching bronchial tubes, and probable visceral traces) to an extent that has never been seen previously in any mosasaur. Our study demonstrates that a streamlined body plan and crescent-shaped caudal fin were already well established in Platecarpus, a taxon that preceded Plotosaurus by 20 million years. These new data expand our understanding of convergent evolution among marine reptiles, and provide insights into their evolution''s tempo and mode.     

Museums, collections and biodiversity inventories

Natural history museums area at a turning point in their history. To play a central role in research on biodiversity, they must change their mode of operation and public image. Collections have grown in a haphazard manner, depending on the interests and preferences of successive curators. There is an urgent need to create international networks and standard practices among museums, to meet the challenge of the biodiversity crisis.     

Evolution and the Second Law of Thermodynamics: Effectively Communicating to Non-technicians

Given the degree of disbelief in the theory of evolution by the wider public, scientists need to develop a collection of clear explanations and metaphors that demonstrate the working of the theory and the flaws in anti-evolutionist arguments. This paper presents tools of this sort for countering the anti-evolutionist claim that evolutionary mechanisms are inconsistent with the second law of thermodynamics. Images are provided to replace the traditional misunderstanding of the law, i.e., “everything always gets more disordered over time,” with a more clear sense of the way in which entropy tends to increase allowing a thermally isolated system access to a greater number of microstates. Accessible explanations are also provided for the ways in which individual organisms are able to minimize entropy and the advantages this conveys.     

The Hemocyanin from a Living Fossil, the Cephalopod Nautilus pompilius: Protein Structure, Gene Organization, and Evolution

By electron microscopic and immunobiochemical analyses we have confirmed earlier evidence that Nautilus pompilius hemocyanin (NpH) is a ring-like decamer (M_r = ∼3.5 million), assembled from 10 identical copies of an ∼350-kDa polypeptide. This subunit in turn is substructured into seven sequential covalently linked functional units of ∼50 kDa each (FUs a–g). We have cloned and sequenced the cDNA encoding the complete polypeptide; it comprises 9198 bp and is subdivided into a 5′ UTR of 58 bp, a 3′ UTR of 365 bp, and an open reading frame for a signal peptide of 21 amino acids plus a polypeptide of 2903 amino acids (M_r = 335,881). According to sequence alignments, the seven FUs of Nautilus hemocyanin directly correspond to the seven FU types of the previously sequenced hemocyanin “OdH” from the cephalopod Octopus dofleini. Thirteen potential N-glycosylation sites are distributed among the seven Nautilus hemocyanin FUs; the structural consequences of putatively attached glycans are discussed on the basis of the published X-ray structure for an Octopus dofleini and a Rapana thomasiana FU. Moreover, the complete gene structure of Nautilus hemocyanin was analyzed; it resembles that of Octopus hemocyanin with respect to linker introns but shows two internal introns that differ in position from the three internal introns of the Octopus hemocyanin gene. Multiple sequence alignments allowed calculation of a rather robust phylogenetic tree and a statistically firm molecular clock. This reveals that the last common ancestor of Nautilus and Octopus lived 415 ± 24 million years ago, in close agreement with fossil records from the early Devonian. [Reviewing Editor: Dr. Axel Meyer] The sequence reported in this paper has been deposited in the EMBL/GenBank database under accession number AJ619741.     

Prehistory, Identity, and Archaeological Representation in Nordic Museums

In this article, I examine the variable representation of Saami (Lapp) prehistory in several Nordic museums. The analysis is situated at the intersection of (1) the examination of the ideology of archaeological practice, (2) the discourse about creation of indigenous identity, and (3) the visual culture of museum exhibitions. I describe and analyze displays about archaeology and prehistory from seven museums in Sweden, Finland, and Norway. The presentation of Saami prehistory differs significantly between majority community museums and those run by Saami communities. These presentations reflect ideologies implicated in building indigenous, nationalist, and pannational identities as well as in establishing legitimacy of Saami claims to land and heritage. Representations of the past are inevitably political because they are about linking people, place, and legitimacy. Ambiguities in these uses of prehistory are discussed, as is the globalizing role of the European Union.     

在中国云南发现狒狒化石

现存狒狒类(Papionin)生活于非洲(如Papio和Theropithoan)、亚洲(如Macaca)和北非(M.sylvanas)。在上新世和更新世,Theropithecus经历了从非洲到亚洲的扩散过程,在印度发现了类似化石。这次在云南中甸金沙江附近发现的下更新世狒狒化石(Papio)证明,如同亚洲猕猴和现代人类祖先一样,非洲狒狒类(Papio和Theropithecus)在同一时期从非洲扩散到亚洲。所不同的是它们没有像猕猴和人类一样生存下来。这次化石的发现对于研究以下生物学问题提供了重要依据1)探讨旧大陆猴类在上新—更新世从非洲到亚洲的扩散过程;2)研究不同旧大陆猴类的进化和环境适应性;3)为现代人类祖先在非洲—亚大陆的扩散研究提供证据;4)由于化石产地包括有人类祖先和其他动物的化石,因此,狒狒在亚洲的生态适应研究将为探讨人类在同一时期的生态适应提供证据。     

Review of the Fossil Evidence for the Origin and Earliest Evolution of the Seed-plants

The earliest identified seed-plants are found in Latest Devonian aged sediments from Northwest Europe and North America and are believed to have evolved from within the progymnosperms, a group of anatomically advanced pteridophytic plants. However, current evidence makes it problematic to determine from which particular progynmospermous lineage the seed-plants evolved, with the major contender being the Aneurophytalean progymnosperms. The evidence for the ancestral stock to the seed-plants is summarised and the morphologies of the earliest known seed-plants are considered. From their first geological occurrence, the seed-plants are morphologically diverse to such an extent that the identification of a single potential ancestral morphology is impossible. In the light of the evidence so far presented, the precise origin of the seed-plants is unresolved and in need of new evidence relating to the progynmosperm/seed-plant transition. Future lines of research are also suggested.     

Trends in the Evolution of Insect Parasitism by Nematodes as Inferred from Fossil Evidence

Fossil evidence can reveal a wealth of information regarding entomogenous nematodes. Amber is an excellent medium for the preservation of such fossils because it protects delicate organisms like nematodes, often along with their insect hosts. Such fossils establish a baseline for the appearance and continuation of parasite lineages as well as parasite-host associations. Thus far, fossil records of insect parasites have been discovered in the following nematode groups: terrestrial and aquatic Mermithidae, Tetradonematidae, Iotonchidae, Diplogasteridae, Allantonematidae, Sphaerulariidae, and Rhabditidae. Records date from 15 to 130 million years, demonstrating that these associations have existed for a considerable length of time.     

Destination Culture: Tourism, Museums, and Heritage

Destination Culture: Tourism, Museums, and Heritage. Barbara Kirshenblatt-Gimblett. Berkeley: University of California Press. 1998.xviii. 326pp.     

Museums and Collections

Abstract

Certain quill techniques and buckskin shirts of the Mandan, Hidatsa, Arikara; and the Crow are discussed Described are the plaited technique, its distribution, Manufacture, variation of style, pattern, and the type of clothing upon which it appeared. Attention is drawn to specific examples in European collections. The same type of information is covered for the quill-wrapped horse hair technique and quill decorated shirts.