Natural History Research Experiences
Research Training Program 2002
Cameron, David Michael
Cyanotis is the third largest genus of Commelinaceae in Africa, with approximately 25 species. The genus is widespread outside of forested habitats, occurring often in dry habitats, but it also includes an aquatic species. Using morphological and anatomical differences, Cyanotis repens, a new perennial African species, is described from tropical Africa. Plants differ from the similar species C. foecunda and C. nyctitropa in lacking a distinct base, having solely axillary inflorescences, and in the shape of the terminal swelling of the style. Two distinct subspecies are recognized, C. repens subsp. repens and C. repens subsp. robusta, based on geographic and cytological evidence.
Revision of Hypostomus species of the streams in the upper Rio Parana basin on the State of Sao Paulo, Brazil (Siluriformes: Loricariidae)
The genus Hypostomus Lacépède, 1803, is the most diverse group of the armored catfishes. Most species descriptions of this genus provide limited or incomplete information, making correct identifications difficult, if not impossible. According to literature, 32 nominal species of Hypostomus occur in the upper Rio Paraná region, an area of demonstrated ichthyological endemism. As a consequence, it is likely that at least some, and more likely a number, of the species of Hypostomus that occur in the headwater streams in this drainage basin are endemics, some of which may be undescribed. A geographically focused taxonomic review of the Hypostomus species in the headwater streams is a prerequisite to an understanding of the diversity of the genus in the basin in light of the high species diversity in the region along with the complicated taxonomic history of the reported species. The species of the genus Hypostomus that occur in the streams of the upper Rio Paraná in State of São Paulo, Brazil, were revised, and one potentially undescribed species was identified. Identification of the species as new necessitated the application of multivariate statistics to the problem since many of the characters in these fishes demonstrate a pronounced degree of overlap. Canonical Discriminant Analysis was utilized in the study and was found to be a very good methodology for addressing this type of problem, allowing us separate the species collected in the streams of the region and confirm their identifications using data taken from a number of type series.
The Glass Frogs (Centrolenidae) from the "Río Palenque" Science Center Ecuador; with the Description of a New Species
Cisneros-Heredia, Diego Francisco
Ecuador has the biggest number of amphibian species per unit of area in the world (425 species in 276,840 km2). In the last decade, conservative estimates indicate that at least 26 species of Ecuadorian amphibians have declined or gone extinct. The reasons for this crisis are not clear but have been related to habitat destruction, climate change, and/or fungal disease such as the chytridiomycosis.
The Río Palenque Science Center (RPSC) was among the last remnants of tropical rainforest in the western lowlands of Ecuador. Twenty years ago, investigations done by R. McDiarmid and others lead to the discovery of an amazing herpetofauna, including several undescribed species. However, the expansion of the agricultural frontier and transformation of the forest remnants into oil palm and banana plantations destroyed this site. Among the species identified from RPSC were five species of glass frogs (Family Centrolenidae): Centrolene prosoblepon, Cochranella spinosai, Hyalinobatrachium fleischmanni, Hyalinobatrachium valerioi, and an undescribed species of the genus Centrolene restricted to the RPSC. This research analyzed the morphological characters and natural history of the five glass frogs of RPSC in order to describe the new species of Centrolene from RPSC which is critically endangered, if not extinct. The new species is characterized by combination of the following characters: 1) a distinctive coloration with yellow dorsolateral stripes; 2) the presence of an exposed prepolicall spine; 3) a humeral spine in the males; and, 4) a unique nuptial pad between the fingers II and I.
The Isle of Skye, Scotland, is a part of the British Tertiary Volcanic Province, an area which experienced intense igneous activity associated with continental separation and lithospheric extension approximately 58 million years ago. Two main plutonic centers and a variety of minor intrusions invade the Mesozoic strata of the island. While the majority of these minor intrusions are regional, such as the vast NNW trending doleritic dike swarm, a smaller number of intrusions are associated with the development of the local plutonic centers. The picrite dikes of Northern Skye are one of three groups of picrite intrusions on Skye and its surroundings that have been grouped on the basis of previous research. The other two are the picrite sills of Northwest Trotternish (Simkin, 1965) and the picrite dikes and sills of Southern Skye (Drever and Johnston, 1958; Gibb, 1968). The purpose of this research was to examine the petrology of the picrite dikes of Northern Skye, with emphasis on the chemical compositions of their olivines and spinels in order to assess their possible genetic relationship with the other two groups. The picrite lava flow of An Carnach, because of its olivine rich composition, and thus its possible relationship to the intrusions, was also included in this study. Compositional analysis was completed on a JEOL8900-R electron microprobe and assisted with digital transmitted light images.
The results showed very little variation among olivine core compositions for the Northern picrite dikes, ranging from Fo90 to Fo92. Olivine compositions from the picrite sills of Northwest Trotternish and the picrite lava flow of An Carnach indicate that they are not a part of the same intrusive group as the Northern dikes, yet due to their own compositional similarities these two groups may share a similar genetic history. The picrite sills and dikes of Southern Skye showed a strong petrological and compositional resemblance to the Northern dikes, suggesting that they may be a single intrusive suite, sharing a similar origin and time of emplacement late in the volcanic sequence.
Edmonds, Douglas Arthur
Some subduction-related volcanic arcs demonstrate an increase in potassium content as distance from the trench increases. Geologists have proposed two different mechanisms that may act additively to explain these trends: 1) the degree of partial melting of the mantle decreases as distance from trench increases, and 2) crustal contamination of the ascending magma increases with distance from trench. Insight into these hypotheses can be gained by studying the Mexican Volcanic Belt (MVB), which is unique among the world’s subduction-related volcanic arcs because it forms a 15-degree angle with the N-W-trending Middle America Trench. Crustal thickness increases eastward along the MVB, and over the past several million years the focus of activity in the MVB has migrated southward toward the trench. Accordingly, it should be possible to isolate the contribution of the first mechanism within the MVB by focusing on N-S-trending volcanic chains that have migrated southward over crust of relatively constant thickness. This research yielded two important results: 1) K2O concentrations for each chain decrease significantly from N to S, supporting the role of decreasing partial melting with increasing distance to the trench, and 2) K2O content for the three volcanic chains increase from W to E, also consistent with the eastward increase in trench distance, but perhaps also evidence for enhanced eastward contamination by thicker continental crust.
Freeburg, Adam Karl Raymond
The process of plant domestication was an important technological innovation that revolutionized human society. The discovery of this process through material remains in the archaeological record allows researchers to investigate the process of cultural and societal change. The domestication of Helianthus annus is documented by the change in size through time of preserved seeds and achenes (sunflower fruit). Most material is preserved through carbonization. This process causes seeds and achenes to shrink. Reconstructive corrections are then necessary to estimate original seed size, after which seeds can be comparatively analyzed. For the past 24 years, these corrections consisted of a set of static factors that were added ubiquitously to all recovered carbonized materials. A recent archaeological finding has called this practice into question. Experiments completed as part of the RTP program have shown that sunflower seeds and achenes, when carbonized, do not Further research will provide new, variable reconstructive corrections that are dependent upon factors such as original size, time in carbonizing environment, and temperature of carbonization
Garrett, Sarah Ellen
Based on 232 samples of leafrollers collected from 1986 to the present, we documented 171 species of tortricid moths from Great Smoky Mountains National Park. Estimates of the actual fauna ranged from 185 (bootstrap) to 224 (Chao1). Of the 39 sampling localities, we compared species richness of the ten most frequently sampled sites (n 6 sampling bouts) and found a correlation coefficient (r2) of 0.7765 between number of species and number of sampling bouts. Community phenology, based on cumulative records, indicated that adult activity is lowest from February to April (<10 species per month), increases considerably in May, continues to increase in June, and gradually decreases through November. No species were captured in January or December. This pattern differed slightly from that reported for the tortricid fauna of Kentucky, and this deviation, coupled with evidence that GSMNP has been under-sampled during the spring, partially explains differences between documented and estimated species richness (i.e., the spring fauna may be under-sampled). We also examined the spatial and temporal distribution of each species within the park.
The redlip blenny, Ophioblennius atlanticus, is a small (< 25 cm) fish that perches on coral or rocky reefs in shallow tropical waters of the Atlantic Ocean. This fish has a broad geographical distribution, ranging north to the Azores, south to St. Helena Island and Brazil, west to the western Caribbean, and east to the west coast of Africa and Gulf of Guinea. Based on morphology, a single species comprising two subspecies traditionally has been recognized (Springer, 1962). More recently, Muss et al (2001) compared a 680-bp region of mitochondrial cytochrome b among 171 individuals from 10 localities to determine genetic differences. Their results suggest that O. atlanticus comprises not one but five species, geographically distributed as follows: 1) Brazil, 2) Caribbean/western Atlantic, 3) eastern Atlantic (Saõ Tomé), 4) southern mid-Atlantic (Ascension/St. Helena), and 5) northern mid-Atlantic (Azores/Cape Verde). The purpose of the present study was to determine if morphology supports the recognition of five species of Atlantic Ophioblennius. Using digital or film techniques, 280 preserved specimens were radiographed, and counts were made of dorsal- and anal-fin rays, and vertebrae. Specimens were then chosen from representative locations to clear and stain, a process that enzymatically digests muscle tissue and stains both cartilage and bone, leaving a clearly visible skeleton that can be examined microscopically to determine differences in the shapes of bones or cartilage. Finally, external structures and patterns of pigmentation were examined. The results of this research suggest that five geographically distinct groups of Atlantic Ophioblennius can be identified on the basis of pigment patterns: 1) Brazil, 2) Caribbean/western Atlantic, 3) eastern Atlantic (Senegal), 4) southern mid-Atlantic (St. Helena/Ascension), and 5) northern mid-Atlantic (Azores/Canaries/Madeira). One of these, the Caribbean/western Atlantic, also can be distinguished based on fin-ray and vertebral counts. Lineages recognized in this morphological study generally correspond geographically with groups recognized in the genetic study, supporting the existence of at least five species of Ophioblennius in the Atlantic. Further study of specimens with well-preserved pigment patterns is needed to determine to which species populations from certain eastern Atlantic localities (e.g. Saõ Tomé, Cape Verde) belong. Future work will include describing or re-describing all Atlantic species of Ophioblennius and reconstructing phylogenetic relationships among them; from the latter, the pattern of speciation of "the redlip blenny" in the Atlantic Ocean will be hypothesized. Future studies of similarly distributed shorefishes may greatly increase our estimates of fish diversity in the tropical Atlantic.
Brucellosis, as a pathogen to humans, is a disease caused by three bacteria in the genus Brucella and is passed to humans through a variety of intermediate hosts including many animals. Brucella melitensis is the species that primarily affects goats, which are thought to be the second oldest domesticate (domesticated ca. 9,000BP), and is passed to humans through the consumption of milk and contaminated meat. Today brucellosis is endemic in many Middle Eastern countries, but little is known about the origins of brucellosis as a pathogen to humans or about the dispersal patterns of brucellosis in the past. To better address these issues we reviewed clinical literature and observed radiographs of modern cases of brucellosis to determine the skeletal manifestations of the disease. Next we evaluated 184 sacra and 288 innominates for signs of sacroilitis (one manifestation of brucellosis) from five different Middle Eastern human samples. These samples included: two from Egypt (12th dynasty 1991-1782 BCE and 25th dynasty 747-657 BCE), one from Jordan (Bab edh-Dhra 3,150-3,000 BCE), and two from Bahrain island (2,300-2000 BCE and 2000-1700 BCE). We then radiographed seven innominates that showed possible signs of brucellosis. We found that one female out of 19 individuals from the 25th dynastic Egyptian collection has sacroilitis that could have been caused by brucellar infection. This is a prevalence of 5.2% of Egyptians in this 25th dynasty site and is a rate close to what would be expected in a sample in which the disease is endemic.
Iriarte, Kristen Elizabeth
Modern technology, along with the exponentially growing population, has led to human travel and occupancy in areas of the world never inhabited before. The major issues here are events rare such great earthquakes and certain volcanic eruptions that now result in fatalities more frequently. The focus here is an event at Arenal Volcano, Costa Rica, where two individuals sustained fatal injuries in a pyroclastic flow erupted on August 23, 2000, in spite of active seismic monitoring. Arenal volcano has been continuously active since it first erupted in 1968, killing 78 individuals. In order to identify any predictive tools useful in preventing this type of tragedy, seismic data from the event were examined. Individual signals were characterized and plotted in order to create a 7-month history before the event. The August 23rd event has a distinct signal that occurred briefly in June and July, but not nearly with the length or magnitude of that of the fatal event. While the number of events steadily increased in the three months leading up to the August 23rd event, we found no patterns that could be used to predict pyroclastic flows. Samples from the flow were examined with an electron microprobe using WDS and EDS in order to gain information on water content. Classically, the presence of higher levels of calcium within plagioclase grains indicates higher water content upon crystallization. Also, higher water content is often an indicator of a higher level of explosive potential. Thus, comparing samples from the fatal pyroclastic flow to a "normal" lava flow will indicate whether the magma composition could have been responsible for the pyroclastic flow. In this study, the Ca levels of the pyroclastic flow block were not statistically different from those of the lava flow, and thus the mechanism of eruption could have been simply an abnormally large volume of buoyant magma moving out of the crater, responsible for the unusual seismic signal (Type X). While the prediction of hazardous pyroclastic flows using scientific data was not illustrated through this research, the methods of data reduction engaged here were only some of the few available to predict and study events.
Knapp, Michelle Christine
In recent years, the monophyly of bat genera, families, and even the order has been called into question. In light of this debate, any information that can be gained by molecular or morphological data may be helpful. While pelage and dentition are well-described, soft mouthpart morphology has been largely ignored.
We looked at structures occurring in the buccal cavity between the gums and the lips. Two buccal cavity structures found in several taxa are papillae on the insides of the lips and a ridge between the lips and teeth. Their distribution within the Chiroptera supports Teeling et al.'s (2002) revision of bats into Yinpterochiroptera and Yangochiroptera rather than the traditional Megachiroptera and Microchiroptera.
Phylogeny and depth ecology of the Late Cretaceous planktonic foraminifera species of Globigerinelloides
McCarren, Heather Kristen
At least eight species of foraminifera in the genus Globigerinelloides (G. multispinus, G. prairiehillensis, G. messinae, G. subcarinatus, G. volutus, G. alvarezi, G. aspensis, and G. impensus) are frequently identified in various studies of Late Cretaceous marine sediments, but opinions vary as to which of these species should be treated as junior synonyms. In an effort to stabilize the taxonomy of this group primary type specimens of most of these species were compared with Globigerinelloides morphotypes from the upper Campanian- Maastrichtian of ODP Site 690 (Weddell Sea), at least two Maastrichtian sample levels at DSDP, Sites 463 and 465 (tropical Pacific), and the Turonian-Maastrichtian of DSDP Site 511 (Falkland Plateau). Ontogenetic morphometric data, coiling metrics and shape analysis based on high-resolution x-ray images from umbilical and edge views were extremely useful in characterizing population variability for each of these planktonically coiled morphotypes.
Our results indicate that Late Cretaceous Globigerinelloides include two distinct lineage groups, one with 10 to 15 chambers and the other with 20 to 25 chambers in adult specimens. Differences in chamber shape, chamber size increase rates, and external shell ornamentation are used to delineate species populations within these two lineage groups. Stable isotope analyses of the biometrically differentiated Globigerinelloides taxa will be obtained to determine their relative depth ecologies. Pre-Campanian Globigerinelloides taxa will be similarly analyzed to reconstruct their Late Cretaceous phylogenetic history.
Newsom, Amanda Joy
This study was designed to identify trends in the procedures used by the Smithsonian Institution to acquire specimens for display and research, and in popular sentiment about cetaceans since 1900. Publications from Scientific American and National Geographic Magazine provided information on how cetaceans have been presented to the general public during the 20th century. The specimens considered in this study were those collected for the Smithsonian Institution for whom the year of collection is known. The collection's database, accessions records and associated literature were consulted in an attempt to ascertain circumstances of death for each specimen. Q- and R- mode cluster analyses were performed using correlation and Bray-Curtis coefficients to determine the relatedness of decades and variable distinctions, respectively. At the beginning of the 1900's, whaling was a worldwide operation, and articles about cetaceans focused mainly on the economic and technological standing of the industry. Most of the cetaceans acquired by the Smithsonian in these years were purposefully captured from the wild. Specimens acquired from strandings now dominate the museum's collection. Popular articles in the 1990's were largely concerned with general cetacean biology, indicative of a new public awareness of these animals as possessing some intrinsic value. This study revealed that as the public has become more interested in cetaceans as organisms rather than as commodities, the collections of the Smithsonian Institution rely more heavily on incidentally caught and stranded animals than on those captured from the wild. It also demonstrates the power of museum collections in historical interpretation of changing human awareness of particular animals.
The Effect of Depositional Environment and Preservation on the Composition of Paleogene Pollen Assemblages
Nowak, Michael Dennis
In light of recent evidence validating the reality of anthropogenic warming, there is a concerted effort to understand Global Climate change and its effect on plants and animals. In the early Paleogene, approximately 55 million years ago, there was a rapid Global warming event called the Initial Eocene Thermal Maximum. My project is part of a larger effort to understand floral response to rapid climate change in the past. The most effective way to study floral trends in the past is through dispersed fossil pollen, or palynoflora. Compared to most megafossils (leaves and fruits), pollen preserves very well in fine-grained sedimentary rocks. Stratigraphic sampling density is therefore much greater. However, when there are apparent changes in the palynoflora within a stratigraphic section, it is difficult to know whether they represent large regional changes in the plant community, or whether they merely represent local changes such as a windstorm, or a fire. In an attempt to clarify this problem, this study investigates the lateral palynofloral variation within an early Paleogene lignite. Preliminary analysis of the data indicates significant palynofloral variability between the samples. The Betulaceous and Taxodiaceous taxa seem to be responsible for the majority of variation between the samples. There also seems to be a relatively strong correlation between the thickness of the lignite and the abundant taxa in the sample. Samples within a thick section of the lignite tend to be dominated by Betulaceae, and thin sections tend to be dominated by Taxodiaceae. To understand this relationship much more data will have to be collected.
Paustian, Megan Elisabeth
The intent of this study was to contribute to the understanding of climate-driven ecological change by generating baseline data on the vegetation of one contemporaneous ancient flora, to be compared with earlier and subsequent species assemblages in future studies. The floral taxa of the Early Permian (Leonardian) Lueders Formation, north-central Texas, were described, identified, and quantified. The study was performed upon seven fossil collections gathered from four localities in the Lueders Formation. This region had been a tropical coastal floodplain.
Worldwide, the Early Permian biota experienced increased aridity caused by global warming. The dominance of floral communities shifted in favor of dryness-tolerant, seed-producing plants over swamp-loving, spore-producing plants. The Lueders flora captured this trend: seed plant foliage was the most common element. Gymnosperm taxa, mainly Walchia sp. and Brachyphyllum sp., dominated the flora. Pteridosperms, seed ferns, were also common. The occurrence of remnant swamp flora, including calamite and lycopod stems and Pecopteris foliage, was relatively infrequent.
Ramjohn, David Damian
To test the hypothesis that the marine fish fauna of Trinidad is the same as that of Tobago, 494 lots of specimens from Trinidad and Tobago, housed in the Fish Collection of the Smithsonian Institution's National Museum of Natural History (NMNH), were examined for capture locations and to verify species identification. Additional data from four research cruises done by the R/V Dr. Fridtjof Nansen around Trinidad and Tobago in 1988 supplemented the collection-based data. These data supported spatial analyses of occurrence by species, families and higher taxa around both islands. The findings indicate significant differences in the fish species composition around both islands thus rejecting the null hypothesis; however, no conclusive statements can be made due to unequal attempts to document the marine fishes of both islands in terms of sampling methods and intensity. Tobago has been subjected to serious systematic inventory, most recently through the efforts of Dave Hardy and NMNH personnel, resulting in over 1300 lots of Tobago specimens compared to 200 for Trinidad in the NMNH Fish Collection. Trinidad has neither been subjected to similar rigorous research nor have the specimens been collected via similar, comparable sampling techniques. Despite this caveat, these results have implications for marine resource management, in terms of necessitating different strategies based on the dominant groups around each island, and provide direction for future research. This research suggests that the marine fish fauna of Trinidad is not the same as that of Tobago.
Runyan, Andrea Michelle
Epidemiological and clinical studies suggest an association between periodontal disease and heart attack, stroke, diabetes, and respiratory disease. Since these diseases affect mainly soft tissue and cause few observable changes to bone, they are difficult to diagnose in archaeological specimens. However, if periodontal disease is correlated with certain systemic diseases, it may be possible to infer cause-of-death from dental condition. To investigate this possibility, the numbers of carious lesions penetrating the pulp, abscesses, and pre-death tooth losses and the extent of bone change processes on the inner skull surface and were recorded for 414 skeletal specimens from the Robert J. Terry Anatomical Skeletal Collection, a group of skeletons with recorded age-at-death, sex, race, year-of-birth, and cause-of-death. This study utilized a new measure of overall periodontal disease, termed "periodontal distress sum," which represented the number of sockets exhibiting one or more of the studied dental disease conditions. Kruskal-Wallis analysis of variance tests revealed that the periodontal distress sum differed significantly (p=0.033) between individuals who had died from myocarditis (average: 10.123) and people with a cause of death unassociated with periodontal disease (average: 8.250). Surprisingly, respiratory disease fatalities exhibited a statistically different (p=0.017), lower mean periodontal distress sum (6.241) than the control group (8.250). No significant differences were observed between the control group and vascular disease fatalities. Nor did dental disease statistics vary significantly between controls and disease groups when individuals were grouped into age-at-death cohorts. Generally severe periodontal disease and other characteristics of the Terry Collection may render it less suited than other skeletal collections for the type of study likely to demonstrate a correlation--namely one which, like clinical studies which have demonstrated correlations, accounts for even minor periodontal disease. However, the Terry Collection was exceptionally suited for this study's demonstrations that endocranial bone activity is positively correlated with both age and periodontal disease. This and other trends revealed by the study provoke additional investigations of the relationship between periodontal disease and race, sex, inflammation, and cause-of-death.
Redefining mongoloid: can inter landmark distances be used to discriminate between Native Americans and East Asiatic individuals?
Seebauer, Jessica Lynne
The Native American Graves Protection and Repatriation Act (NAGPRA) of 1990 mandates the repatriation (return) of Native American human remains currently housed in federally-funded agencies, museums, and institutions to proper tribal representatives upon request. The Smithsonian Institution, home of the largest skeletal collection in the world, has a Repatriation Office devoted to the documentation, analysis, and return of Indian remains - a process involving information from accession files, archeological data, and other miscellaneous archival records to ensure repatriation of skeletal material to the correct tribes. However, reliance on museum records as the sole source of information regarding tribal affiliation can result in the misclassification of remains; in many cases, museum specimens can be poorly documented or misdocumented. Thus, it has become increasingly obvious that museums should use biological data-such as craniometrics-as a check against museum documents, to verify that the remains are actually affiliated to the tribes indicated. Previous research has demonstrated that digitizing three-dimensional landmarks is successful in discriminating between Native American, African-American, and European-American populations with up to 96% accuracy. My research centers on the morphometric discrimination between Native American populations and East Asian populations. This discrimination is more challenging because Native Americans are morphologically more similar to East Asians (due to a more recent common ancestor), and are therefore more likely to be misclassified as Asian than either "white" or "black" (and vice versa). Using a three-dimensional digitizer, landmark coordinates were collected from over 350 skulls of East Asian and South Pacific individuals in the NMNH collections to identify the best interlandmark distances (ILD's) to distinguish between many groups having similar morphologies. Eighty-six landmark coordinates were identified yielding 3, 655 possible interlandmark distances. The best coordinate landmarks were identified using stepwise discriminant function analysis. The analysis suggested that Type 1 landmarks (points where two bones join) provide the best discriminate functions for separation of Native American and Asiatic populations with 95% accuracy. Morphometric data collection and analysis like this is important because the presence of human remains excavated in American soil does not always indicate Native American affiliation, a point illustrated by Chinese cannery cemeteries in Alaska.
Skeeles, Angela Dawn
We used Principle Components Analysis (PCA), a multivariate method, to analyze the cranial size and shape of eight Neotropical cat species. Preliminary patterns of sexual dimorphism and geographic variations were considered qualitatively by interpreting scatterplots generated using a PCA on SYSTAT. Size variation accounted for at least 80% of the variation between individual specimens except in Leopardus tigrinus (71.6%). In all species except L. tigrinus and L. pardalis, most non-size variation was due to canine diameter. Leopardus wiedii, Puma concolor, Panthera onca, and Oncifelis geoffroyi males tended to have larger canines than females. L. wiedii from Mexico were smaller in general, while Panamanian individuals were larger. L. pardalis from Panama were larger and had greater breadth across canines and canine diameter than individuals from Texas, USA. P. onca from Argentina tend to be larger with larger canines, whereas individuals from Guyana were smaller with smaller canines. P. concolor from Argentina were larger than others. Among the small species (group 1), L. tigrinus was readily differentiated from the other three by size and shape. The remaining three species are remarkably similar in skull size and shape. L. pardalis and Puma yaguarondi are distinct in both size and shape. Finally, we found P. concolor and P. onca to be extremely similar in patterns of variation of size and shape of the skull.
A Study of Genetic Variation in Musella (Musaceae): an endemic monotypic genus from Southwestern China
Musella lasiocarpa is a large perennial herb endemic to southwestern China, primarily in central and western Yunnan, occurring inside the conifer-oak mixed forest domain at elevations of 1500-2500 m. Several ethnobotanical uses have been reported for Musella lasiocarpa; however true wild populations are unknown at the present time. The objective of this project was to study genetic variation found between and within populations, through isozyme analyses. Musella presented great genetic variation and its geographical distribution does not coincide with the genetic distribution. It has probably been transported and introduced into new areas by humans.
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