Cryptic species within Amphicarpaea bracteata (Leguminosae): evidence from isozymes, morphology, and pathogen specificity

1996 ◽  
Vol 74 (10) ◽  
pp. 1640-1650 ◽  
Author(s):  
Matthew A. Parker
Keyword(s):  
Regional Scale ◽  
Geographic Origin ◽  
Leaf Traits ◽  
Biological Species ◽  
The Other ◽  
Single Variable ◽  
Hybrid Individual ◽  
Variable Species ◽  
Pattern Of Variation ◽  
Amphicarpaea Bracteata

All North American plants of the genus Amphicarpaea are currently classified into a single variable species (Amphicarpaea bracteata). However, an isozyme analysis of 33 populations from a 1000-km region revealed the presence of two divergent lineages (I, II) that shared no alleles in common at 7 of 18 loci examined. These lineages coexisted on both a local and a regional scale with virtually no hybridization: among nearly 1000 plants analyzed, only a single hybrid individual was found that had alleles from both lineages. A multivariate analysis of seven leaf traits showed that these lineages were morphologically distinct and that populations from the same lineage resembled each other regardless of geographic origin. The two lineages also showed divergent responses to isolates of the pathogen Synchytrium decipiens: pathogens sampled from either lineage failed to reproduce successfully on hosts of the other lineage. The correlated pattern of variation for all traits examined implies that these lineages constitute two separate biological species. Consistent (though less extreme) trait differences were also detected among two clusters of populations within lineage I, suggesting that this lineage may be further subdivided into two reproductively isolated sets of populations. Keywords: Amphicarpaea, electrophoresis, geographic variation, hybridization, Leguminosae.

The Importance of Being Human

1991 ◽  
Vol 29 ◽  
pp. 35-62 ◽  
Author(s):  
Cora Diamond
Keyword(s):  
Biological Species ◽  
The Other ◽  
Human Being ◽  
Human Beings ◽  
Moral Relevance ◽  
Other Hand ◽  
Biological Classification

I want to argue for the importance of the notion human being in ethics. Part I of the paper presents two different sorts of argument against treating that notion as important in ethics.A. Here is an example of the first sort of argument.What makes us human beings is that we have certain properties, but these properties, making us members of a certain biological species, have no moral relevance. If, on the other hand, we define being human in terms which are not tied to biological classification, if (for example) we treat as the properties which make us human the capacities for reasoning or for self-consciousness, then indeed those capacities may be morally relevant, but if they are morally significant at all, they are significant whether they are the properties of a being who is a member of our species or not. And so it would be better to use a word like ‘person’ to mean a being that has these properties, to bring out the fact that not all human beings have them and that non-human beings conceivably might have them.

Making deeper insights part 2

2021 ◽  
pp. 247-270
Author(s):  
Owen L. Petchey ◽  
Andrew P. Beckerman ◽  
Natalie Cooper ◽  
Dylan Z. Childs
Keyword(s):  
Data Analysis ◽  
Descriptive Statistics ◽  
The Other ◽  
Single Variable ◽  
Individual Variables

In the previous chapter we looked at individual variables; however, a sample may involve more than one variable. Moreover, data analysis is usually concerned with the relationships among two or more variables. These relationships might involve the same (e.g. numeric versus numeric) or different (e.g. numeric versus categorical) types of variable. In either case, we need to understand how the values of one variable relate to and/or depend on those of the other. Just as with single-variable analyses, we use both descriptive statistics and graphical summaries to explore such relationships. This chapter focuses on associations between variables. An association is any relationship between two variables that makes them dependent, i.e. knowing the value of one variable gives us some information about the possible values of the second variable. The main goal of this chapter is to show how to use descriptive statistics and visualizations to explore associations among different kinds of variables.

Taxonomic status of Protankyra ramiurna and Protankyra benedeni (Holothuroidea: Apodida: Synaptidae)

Zootaxa ◽  
2017 ◽  
Vol 4324 (3) ◽  
pp. 518 ◽  
Author(s):  
JÉSSICA PRATA ◽  
MICHELA BORGES ◽  
CYNTHIA L. C. MANSO ◽  
MARTIN LINDSEY CHRISTOFFERSEN
Keyword(s):  
Comparative Analysis ◽  
Taxonomic Status ◽  
Distinct Species ◽  
First Record ◽  
Brazilian Coast ◽  
Single Variable ◽  
Variable Species

This study presents a review of the species Protankyra ramiurna Heding, 1928 and Protankyra benedeni (Ludwig, 1881) from the Brazilian coast. Some authors consider that these two taxa represent a single variable species. Our comparative analysis of external characters, anatomy and ossicle morphology indicates that they represent distinct species. This is the first record of Protankyra ramiurna from Brazil. 

scholarly journals Interdecadal Variability of the South American Precipitation in the Monsoon Season

2015 ◽  
Vol 28 (2) ◽  
pp. 755-775 ◽  
Author(s):  
Alice M. Grimm ◽  
João P. J. Saboia
Keyword(s):  
Function Analysis ◽  
Monsoon Season ◽  
Regional Scale ◽  
The Other ◽  
Interdecadal Variability ◽  
Monthly Precipitation ◽  
Monsoon Precipitation ◽  
Climatic Indices ◽  
Continental Scale ◽  
Sst Anomalies

Abstract Interdecadal variability modes of monsoon precipitation over South America (SA) are provided by a continental-scale rotated empirical orthogonal function analysis, and their connections to well-known climatic indices and SST anomalies are examined. The analysis, carried out for austral spring and summer, uses a comprehensive set of station data assembled and verified for the period 1950–2000. The presented modes are robust, consistent with previous regional-scale studies and with modes obtained from longer time series over smaller domains. Opposite phases of the main modes show differences around 50% in monthly precipitation. There are significant relationships between the interdecadal variability in spring and summer, indicating local and remote influences. The first modes for both seasons are dipole-like, displaying opposite anomalies in central-east and southeast SA. They tend to reverse polarity from spring to summer. Yet the summer second mode and its related spring fourth mode, which affect the core monsoon region in central Brazil and central-northwestern Argentina, show similar factor loadings, indicating persistence of anomalies from one season to the other, contrary to the first modes. The other presented modes describe the variability in different regions with great monsoon precipitation. Significant connections with different combinations of climatic indices and SST anomalies provide physical basis for the presented modes: three show the strongest connections with SST-based indices, and two have the strongest connections with atmospheric indices. However, the main modes show connections with more than one climatic index and more than one oceanic region, stressing the importance of combined influence.

Variation in Australian populations of Halfordia kendack s.l. (Rutaceae): evidence from leaf essential oils

2004 ◽  
Vol 17 (6) ◽  
pp. 571 ◽  
Author(s):  
Paul I. Forster ◽  
Joseph J. Brophy ◽  
Robert J. Goldsack
Keyword(s):  
Essential Oils ◽  
Species Distribution ◽  
Methyl Eugenol ◽  
The Other ◽  
Oil Composition ◽  
Altitudinal Range ◽  
Leaf Oil ◽  
Variable Species ◽  
Low Altitude

The leaf oils of Halfordia kendack (Montrouz.) Guillaumin s.l. from locations throughout its range in Australia were investigated to ascertain if the disjunct nature of the species' distribution affected their composition and whether any variation detected supported the recognition of a second species (H. scleroxyla F.Muell.). While three groups of populations could be classified on the basis of leaf oil composition, these groups were not associated with geographic locality or altitudinal range and habitat. It was found that plants from low altitude sites in north Queensland all produced leaf oils that contained the aromatic ethers methyl eugenol and elemicin in variable amounts, included in an otherwise terpenoid oil. Plants from the other three areas examined; north Queensland montane sites, south-east Queensland low altitude and south-east Queensland montane sites, all produced leaf oils which were terpenoid in nature and contained no aromatic ethers. This lack of correlation in leaf oil composition with locality or habitat would lend support to the proposition that Halfordia exists in only one variable species in Australia.

Morphometric studies of the Euphorbia esula group (Euphorbiaceae) in North America

1990 ◽  
Vol 68 (9) ◽  
pp. 1978-1988 ◽  
Author(s):  
C. W. Crompton ◽  
A. E. Stahevitch ◽  
W. A. Wojtas
Keyword(s):  
North America ◽  
Morphological Characters ◽  
Leafy Spurge ◽  
Principal Coordinate Analysis ◽  
Euphorbia Esula ◽  
Eastern North America ◽  
Single Variable ◽  
Authentic Material ◽  
Variable Species ◽  
Euphorbia Cyparissias

Leafy spurge and cypress spurge are important weeds of pastures and unimproved rangeland in western and eastern North America, respectively. Taxonomists disagree as to whether leafy spurge is a single variable species or an aggregate of two or more species. Morphometric techniques (clustering by incremental sum of squares and principal coordinate analysis) were used to analyze relationships in leafy spurge and its allies. On the basis of studying 26 morphological characters found in 200 collections representing 32 putative taxa, we concluded that in North America only four species should be recognized, namely, Euphorbia agraria Bieb., Euphorbia cyparissias L., Euphorbia esula L., and Euphorbia ×pseudoesula Schur. A key to these taxa is provided. No authentic material of Euphorbia lucida Waldst. & Kitt. and Euphorbia salicifolia Host was found from this continent in the collections we examined.

Budget Deficits: A Major Cause of Inflation?

1978 ◽  
Vol 6 (1) ◽  
pp. 115-127 ◽  
Author(s):  
Ansel M. Sharp ◽  
Phyllis Smith Flenniken
Keyword(s):  
Economic Theory ◽  
Empirical Evidence ◽  
Money Supply ◽  
The Other ◽  
Real Output ◽  
Budget Deficits ◽  
Single Variable ◽  
Other Hand

This paper examines the proposition that budget deficits are a major cause of inflation. Economic theory does not unconditionally support the proposition, and available empirical evidence does not support the proposition. During periods of expansion, 1949–1973, the increases in the money supply that can be directly traced to budget deficits are often a contributing but not necessarily a major cause of inflations. On the other hand, the fiscal effects of the budget, because of the automatic growth in federal receipts, are usually checking the growth in both prices and real output. Based on the discussion and data presented in this paper, the deficit hypothesis cannot be accepted. Inflations are too complicated phenomena to be explained by a single variable such as budget deficits.

XVII.—On some Cretaceous Echinoidea from the Neighbourhood of Lobito Bay

1917 ◽  
Vol 51 (3) ◽  
pp. 585-587 ◽  
Author(s):  
J. W. Gregory
Keyword(s):  
Posterior Margin ◽  
The Other ◽  
Variable Species

Nine species of Echinoidea were described by De Loriol From Benguella and mainly from the neighbourhood of Dombe Grande.1. One of his species, Epiaster catumbellensis, is common in the Lobito district. It is recorded by Be Loriol from the Inflata beds at Catumbella, and the younger Cyprina ivensi sandstone at Dombe Grande. It is a variable species. According to the dimensions given by De Loriol, the length varies from 25 to 36 mm., and the breadth varies from 88 to 94 per cent, of the length and the height from 66 to 77 per cent, of the length. His illustrations show that the species has two chief forms: in one the shape is depressed and the posterior margin is nearly vertical; in the other the posterior interambulacrum is subcarinate, and the posterior margin is more sloping owing to the projection of the lower posterior corner. In De Loriol's figure, pl. viii, No. 4, the posterior margin has a slope of only 7° from the vertical; in his fig. 5 this slope is 15° from the vertical.

scholarly journals Can climate shape flight activity patterns of Plebeia remota Hymenoptera, Apidae)?

2012 ◽  
Vol 102 (3) ◽  
pp. 269-276 ◽  
Author(s):  
Sergio D. Hilário ◽  
Márcia de F. Ribeiro ◽  
Vera L. Imperatriz-Fonseca
Keyword(s):  
Solar Radiation ◽  
Climatic Factors ◽  
Activity Patterns ◽  
Geographic Origin ◽  
Climatic Changes ◽  
Flight Activity ◽  
The Other ◽  
Automated System ◽  
Seasonal Differences ◽  
Autumn And Winter

Flight activity of foragers of four colonies of Plebeia remota (Holmberg, 1903) was registered from December 1998 to December 1999, using an automated system (photocells and PLC system). The colonies originated from two different regions: Cunha, state of São Paulo, and Prudentópolis, state of Paraná, Brazil. Flight activity was influenced by different climatic factors in each season. In the summer, the intensity of the correlations between flight activity and climatic factors was smaller than in the other seasons. During the autumn and winter, solar radiation was the factor that most influenced flight activity, while in the spring, this activity was influenced mainly by temperature. Except in the summer, the various climatic factors similarly influenced flight activity of all of the colonies. Flight activity was not affected by geographic origin of the colonies. Information concerning seasonal differences in flight activity of P. remota will be useful for prediction of geographic distribution scenarios under climatic changes.

Highly repeated DNA and allozyme variation between sibling species: evidence for introgression

Genome ◽  
1987 ◽  
Vol 29 (2) ◽  
pp. 272-279 ◽  
Author(s):  
M. L. Arnold ◽  
P. Wilkinson ◽  
D. D. Shaw ◽  
A. D. Marchant ◽  
N. Contreras
Keyword(s):  
Sibling Species ◽  
Dna Sequences ◽  
Clustering Analysis ◽  
Introgressive Hybridization ◽  
Allozyme Variation ◽  
The Other ◽  
Repeated Dna ◽  
Highly Repeated Dna ◽  
Pattern Of Variation ◽  
Two Populations

The Caledia captiva complex of grasshoppers includes two sibling species along with two subspecies. Two populations (Papuan Torresian and Daintree) representing the two sibling species were found to share six allozyme characters and a highly repeated DNA family not found in any of the other Caledia taxa. These two populations showed genic divergence that was equivalent to comparisons between the two subspecies from the complex. Sequenced, cloned repeats from the Papuan Torresian and Daintree taxa showed equivalent variation for both intra- and inter-specific comparisons. A phenetic clustering analysis did not separate the repeats from these two taxa into different clades. Furthermore, the overall genomic organization of the sequence family in the two species is very similar, although the repeats are cytologically dispersed in one form (Papuan Torresian) and clustered in the other form (Daintree). It is argued that the most likely evolutionary explanation for the observed pattern of variation in the allozymes and highly repeated DNA sequences between these types is introgressive hybridization. The possible consequences of such an event are discussed in light of the population genetics and distribution of the present day Caledia taxa. Key words: highly repeated DNA, Caledia, grasshopper, allozymes.

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