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Part III--THE NATURE OF SPECIES AND THE MEANING OF ��SPECIES��: 11 A Multidimensional Approach for Detecting Species Patterns in Malagasy Vertebrates--ANNE D. YODER, LINK E. OLSON, CAROL HANLEY, KELLIE L. HECKMAN, RODIN RASOLOARISON, AMY L. RUSSELL, JULIE RANIVO, VOAHANGY SOARIMALALA, K. PRAVEEN KARANTH, ACH
Pages 201-228

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From page 201... ... The many biologists who, like Mayr, take a primarily zoological perspective, will appreciate the case studies presented by Anne Yoder et al. in "A Multidimensional Approach for Detecting Species Patterns in Malagasy Vertebrates" (Chapter 11) Read the entire page →
From page 202... ... That confusion lies between species criteria, as articulated in various species concepts, which are actually contingent properties of species, and the necessary properties of species as they are understood in the general sense of being evolutionary lineages. Biologists who disagree about which contingent properties of species are the most useful for identification and classification should be able to find common ground by recognizing the contingent, as opposed to necessary, aspect of the features they prefer to study. Read the entire page →
From page 203... ... Given that species are the fundamental unit of evolution, where micro- and macroevolutionary forces converge to generate biological diver sity, a thorough understanding of species distribution and abun dance is critical for understanding the evolutionary, ecological, and biogeographic forces that have shaped Malagasy vertebrate diversity. We illustrate the means by which we apply Mayr's ``three basic tasks'' of the systematist [Mayr, E Read the entire page →
From page 204... ... Using field inventory methods, specimen-based studies, and morphological and molecular analyses, we formu late hypotheses of species identity that then serve as the founda tion for subsequent studies of biology and history. Our experi ence, as well as that of other investigators, has shown that much of the vertebrate species diversity in Madagascar is ``cryptic'' for both biological and practical reasons. Read the entire page →
From page 205... ... In turn, this basic knowledge depends upon the identification and geographic delineation of biological species. In our efforts to understand the evolutionary forces that govern the distribution and abundance of Malagasy vertebrates, we apply a suite of empirical and analytical tools that permit us first to formulate hypotheses of species distinction, and then progress by means of genetic and morphological analysis to questions of the geographic and temporal context of the species' history. Read the entire page →
From page 206... ... There is keen interest among Malagasy officials to prioritize regions of the country in need of protection, and these priorities will be largely based upon basic biological knowledge relating to species diversity and distribution. Given this urgency, we as biologists do not have the luxury to contemplate and deliberate the meaning of species, without simultaneously taking the necessary action required to formulate biological hypotheses of species distribution and abundance. Read the entire page →
From page 207... ... All of the biological and practical variables raised by Mayr apply in the case of species discovery in Madagascar. To confound the issues of cryptic biological diversity, the resolution of species identity has been hampered due to a lack of specimen material and genetic sampling at the population level necessary for understanding patterns of variation. Read the entire page →
From page 208... ... Each study focuses on a species complex endemic to Madagascar, and each, we hope, illustrates the importance of comprehensive biological inventory and the careful examination of associated specimens for analyzing vertebrate species in the context of historical, geographic, phenotypic, and genotypic context. It is this general synthetic approach that allows us to formulate our hypotheses of species identity, which then serve as the fundamental frame Read the entire page →
From page 209... ... Additionally, these data support the monophyly of most of the species contained in the genus Zonosaurus. In this genus, the five most widely distributed species (Zonosaurus aeneus, Zonosaurus karsteni, Zonosaurus laticaudatus, Zonosaurus madagascariensis, and Zonosaurus ornatus) Read the entire page →
From page 210... ... Numbers indicate bootstrap support and posterior probability scores for clades representing various species. Sampling localities are as follows: Northern Madagascar (N) Read the entire page →
From page 211... ... The cytochrome b phylogeny also confirms the species status of the closely related species pair Zonosaurus subunicolor and Z rufipes, which have overlapping distributions. Read the entire page →
From page 212... ... We are presently employing population genetic methods to address these competing dispersal hypotheses, as well as to test the hypothesis that one of the northern rivers in western Madagascar may act as a biogeographic barrier separating T auritus and T Read the entire page →
From page 214... ... , like many members of this most speciose genus of Malagasy mammal, has a complicated taxonomic history. Tenrecs, and shrew tenrecs in particular, exhibit numerous ontogenetic peculiarities that have stymied taxonomists for the better part of a century (see Jenkins et al., 1997; MacPhee, 1987) Read the entire page →
From page 215... ... (b) Despite their striking morphological similarity, members of each haplotype clade are readily distinguished by both a priori and a posteriori morphometric analyses, supporting the recognition of two cryptic species, M Read the entire page →
From page 216... ... . Second, the revised taxonomy of long-tailed shrew tenrecs revealed contrasting patterns of geographic morphological variation. Read the entire page →
From page 217... ... Case 4: Adding a Temporal Dimension to Species Diversification in Mouse Lemurs, Moving from the Field to the Laboratory and Back Again The genus Microcebus was considered monotypic by most authorities, containing the single species murinus (Schwarz, 1931) , from the time of its original description in 1795 until the 1970s. Read the entire page →
From page 218... ... Although it had been assumed that these two populations would belong to a single clade, congruent with their species designation of Microcebus rufus, the two populations were instead found to be paraphyletic with respect to the western species. This result strongly suggests that, contrary to the current recognition of a single species Microcebus rufus, there are at least two species of mouse lemurs in the eastern regions of Madagascar, and potentially many more (Yoder et al., 2000) Read the entire page →
From page 219... ... First, acoustic signals in mouse lemurs seem to evolve extremely rapidly, and second, the greatest levels of acoustic separation occur in the sexual advertisement calls of males. Relevant to the issue of rapid rates, studies of captive mouse lemur colonies in Europe reveal that colonies that have been separated for only a few generations have already begun to develop distinct dialects in their acoustic signals (Zimmermann and Hafen, 2001) Read the entire page →
From page 220... ... . It should be noted, however, that, up to the present, all published studies that have examined sympatric overlap between mouse lemur species have demonstrated sympatry only for Microcebus murinus plus another species (Radespiel et al., 2003; Schmid and Kappeler, 1994; Schwab and Ganzhorn, 2004; Weidt et al., 2004; Yoder et al., 2002; Zimmermann et al., 1998) Read the entire page →
From page 221... ... illustrates et not The do intron ravelobensis figure Yoder remaining species. This from otherwise Microcebus berthae 11.5 lemur fibrinogen but the redrawn mouse FIGURE in are species, Microcebus from Conversely, Read the entire page →
From page 222... ... . Mouse lemurs progressively accumulate fat stores during the wet season (Genin and Perret, 2000) Read the entire page →
From page 223... ... It is therefore of evolutionary consequence to ask whether this unusual system is characteristic of all mouse lemur species and populations, or only to a subset of species and habitats. At present, there is preliminary indication that Microcebus ravelobensis is perhaps unique among mouse lemurs in that it does not enter torpor (Randrianambinina et al., 2003) Read the entire page →
From page 224... ... (2000) Spatial distribution and population composition of the brown mouse le mur (Microcebus rufus) Read the entire page →
From page 225... ... (2003) Daily hypothermia in captive grey mouse lemurs (Microcebus murinus) Read the entire page →
From page 226... ... (1998) Sex-specific usage pat terns of sleeping sites in grey mouse lemurs (Microcebus murinus) Read the entire page →
From page 227... ... (2000) Remarkable species diversity in Malagasy mouse lemurs (Pri mates, Microcebus) Read the entire page →
From page 228... ... (1998) Sym patric mouse lemurs in north-west Madagascar: A new rufous mouse lemur species (Microcebus ravelobensis) Read the entire page →

From page 201...

... The many biologists who, like Mayr, take a primarily zoological perspective, will appreciate the case studies presented by Anne Yoder et al. in "A Multidimensional Approach for Detecting Species Patterns in Malagasy Vertebrates" (Chapter 11)