A Paedomorphocline in Eucalyptus: Natural Variation in the E. risdonii/E. tenuiramis Complex

1991 ◽  
Vol 39 (6) ◽  
pp. 545 ◽  
Author(s):  
RJE Wiltshire ◽  
BM Potts ◽  
JB Reid
Keyword(s):  
Morphological Variation ◽  
Natural Variation ◽  
Natural Populations ◽  
Morphological Data ◽  
Closely Related Species ◽  
Leaf Habit ◽  
Juvenile Leaf ◽  
Adult Leaf ◽  
Morphological Differences ◽  
Fruit Characters

Ontogenetic and morphological variation in 40 natural populations of the closely related species, E. risdonii and E. tenuiramis, were assessed in a multivariate study of juvenile and adult leaf and fruit characters. The present taxonomic separation of the two taxa is based mainly on ontogenetic differences, but this study reveals that the variation between the two taxa in the retention of the juvenile leaf habit is continuous and may represent a paedomorphocline. The morphological data suggest that at least four phenetic groups are required to summarise the morphological variation in the E. risdonii/ E. tenuiramis complex. When ontogenetic variation is removed, the morphological variation between some E. risdonii and some E. tenuiramis populations is also continuous and much smaller than the morphological differences within E. tenuiramis. This suggests that E. risdonii may be the product of relatively recent changes in developmental timing (heterochrony) from E. tenuiramis.

A reassessment of Dioon merolae (Zamiaceae) leads to the description of Dioon salas-moralesae, a new cycad species from Southeastern Oaxaca, Mexico

Phytotaxa ◽  
2021 ◽  
Vol 528 (2) ◽  
pp. 93-110
Author(s):  
JOSÉ SAID GUTIÉRREZ-ORTEGA ◽  
MIGUEL ANGEL PÉREZ-FARRERA ◽  
JEFFREY CHEMNICK ◽  
TIMOTHY J. GREGORY
Keyword(s):  
New Species ◽  
Morphological Variation ◽  
Related Species ◽  
Statistical Tests ◽  
Distinct Species ◽  
Closely Related Species ◽  
Morphometric Variation ◽  
Isthmus Of Tehuantepec ◽  
Morphological Differences ◽  
Recent Evaluation

The cycad genus Dioon comprises 17 species from Mexico and Honduras, all of them delimited based on their morphological variation and geographic distribution. A recent evaluation of the biological variation among Dioon populations from Oaxaca and Chiapas, Mexico, demonstrated that the concept of the species Dioon merolae actually consists of three lineages that should be recognized as different taxa. One lineage was already described as Dioon oaxacensis, leaving the concept of Dioon merolae comprising two lineages distributed on both sides of the Isthmus of Tehuantepec. However, there are conspicuous morphological differences between these two lineages. Here, we tested whether such a differentiation within the concept of Dioon merolae merits the differentiation of two different taxa. We evaluated the qualitative and morphometric variation among populations belonging to the Dioon merolae lineages, and compared it with the closely related species Dioon oaxacensis. Morphological observations and statistical tests demonstrated that the populations of southeastern Oaxaca, traditionally considered as part of Dioon merolae, represent a distinct species that we described as Dioon salas-moralesae. Identifying the diagnostic characters of this new species helps enable an understanding of the criteria that should be considered to delineate the boundaries between other cycad species.

AN ANALYSIS OF INTERSPECIFIC AND INTRASPECIFIC MORPHOLOGICAL DIFFERENCES IN TWO CLOSELY RELATED SPECIES OF AMBLYSEIUS BERLESE USING METHODS OF NUMERICAL TAXONOMY (ACARINA: PHYTOSEHDAE)

1977 ◽  
Vol 109 (12) ◽  
pp. 1605-1618 ◽  
Author(s):  
D.A. Chant ◽  
R.I.C. Hansell ◽  
H.J. Rowell
Keyword(s):  
Host Plant ◽  
Morphological Variation ◽  
Related Species ◽  
Numerical Taxonomy ◽  
Valid Species ◽  
Closely Related Species ◽  
Multivariate Tests ◽  
Taxonomic Methods ◽  
Morphological Differences ◽  
Intraspecific Morphological Variation

AbstractMorphological variation between two closely related species in the genus Amblyseius Berlese was examined by numerical taxonomic methods. Multivariate tests indicated that A. canadensis Chant and Hansell and A. novaescotiae (Chant) represent two separate and distinct morphological groups. This supports their taxonomic retention as valid species. Intraspecific morphological variation was also examined and found to be correlated with climatic and host plant variables.

Patterns of Variation in Eucalyptus sideroxylon A. Cunn. Ex. Woolls. I. Variation in Adult Morphology

1984 ◽  
Vol 32 (3) ◽  
pp. 263 ◽  
Author(s):  
HW Bramwells ◽  
T Whiffin
Keyword(s):  
General Pattern ◽  
The South ◽  
North Central ◽  
Adult Morphology ◽  
The North ◽  
Adult Leaf ◽  
Morphological Differences ◽  
Fruit Characters ◽  
Eucalyptus Sideroxylon

Eucalyptus sideroxylon, a woodland tree occumng in an arc from central and southern Victoria to south-eastem Queensland, is currently divided into subsp. slderoxylon to the north, and subsp. tricarpa to the south. Thirty populations were sampled throughout the range of the species and studied for adult leaf and fruit characters. There were found to be very marked and highly significant morphological differences between the two subspecies, more especially in the fruit characters. Within subsp. sideroxylon there was a general distinction between the inland populations and the more coastal populations, while within subsp. trlcarpa there was similarly a general differentiation of the coastal populations from the northern and north-central Victorian populations. The extent and general pattern of these various differences are documented as a prelude to further studies.

Complementary description of Panonychus caricae Hatzinikolis, 1984, with the resurrection of the genus Sasanychus Ehara, 1978 (Acari, Prostigmata, Tetranychidae)

Zootaxa ◽  
2020 ◽  
Vol 4881 (3) ◽  
pp. 515-531
Author(s):  
TEA ARABULI ◽  
TOMOKO MATSUDA ◽  
MOHAMED W. NEGM ◽  
TETSUO GOTOH
Keyword(s):  
Panonychus Ulmi ◽  
Morphological Data ◽  
Coi Gene ◽  
Morphological Evidence ◽  
Closely Related Species ◽  
World Species ◽  
Maximum Likelihood Tree ◽  
The World ◽  
Morphological Differences ◽  
Fig Trees

A complementary description of Panonychus caricae Hatzinikolis, 1984, is presented based on the morphology of adult female and male individuals collected from fig trees (Ficus sp., Moraceae) in Greece. Morphological differences between Panonychus caricae and two closely related species, Panonychus ulmi (Koch, 1836) and Panonychus hadzhibejliae (Reck, 1947), are discussed. Panonychus caricae can be separated from two other Panonychus species using the length of the female dorsal setae in combination with the ratio between the length of female dorsal opisthosomal setae f2 and h1, and the ratio between the length of dorsal setae sc1 and h1. A phylogenetic maximum likelihood tree was constructed based on the cytochrome c oxidase subunit I (COI) gene of mitochondrial DNA (mtDNA) from 10 species of the subgenus Panonychus s.str. (including the re-described species P. caricae) and the only two species of the subgenus Sasanychus. The phylogenetic tree indicates that these 12 species are clearly separated from each other. The two subgenera, Panonychus s.str. and Sasanychus, comprise strongly supported monophyletic clades with 98% bootstrap values. The convergence of molecular and morphological data (dorsal setae set on tubercles or not, number of tactile setae on tibiae I and II, and patterns of the dorsocentral striae) suggests that Sasanychus should not be classified under the genus Panonychus. Consequently, molecular and morphological evidence supports the resurrection of the genus Sasanychus, which contains two species, S. akitanus (Ehara) and S. pusillus Ehara & Gotoh, as distinct from Panonychus. A key to the world species of Panonychus and Sasanychus is also provided.

scholarly journals Darwin Returns to the Galapagos: Genetic and Morphological Analyses Confirm the Presence of Tramea darwini at the Archipelago (Odonata, Libellulidae)

Insects ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 21
Author(s):  
María Olalla Lorenzo-Carballa ◽  
Rosser W. Garrison ◽  
Andrea C. Encalada ◽  
Adolfo Cordero-Rivera
Keyword(s):  
Nuclear Dna ◽  
Morphological Data ◽  
Consistent Difference ◽  
Santa Cruz ◽  
Morphological Examination ◽  
Closely Related Species ◽  
Senior Synonym ◽  
The Status ◽  
The Subject ◽  
Morphological Differences

The status of the Tramea species present in the Galapagos Islands (Odonata, Libellulidae) has been the subject of a long-standing debate among odonatologists. Here, we use molecular and morphological data to analyze a series of specimens from this genus collected in 2018 from the Islands of San Cristobal, Isabela, and Santa Cruz, with the aim of determining their relationship with Tramea calverti Muttkowski and with their currently considered senior synonym T. cophysa Hagen. We combined sequencing of mitochondrial and nuclear DNA with morphological examination of several specimens of Tramea, including representatives of continental T. cophysa and T. calverti. Our molecular analyses place the Tramea from Galapagos in the same clade as T. calverti, with T. cophysa as a closely related species. The morphological analyses found only one consistent difference between T. cophysa and T. calverti: the presence of an accessory lobe in the male vesica spermalis of T. cophysa that is absent in T. calverti and in the Tramea from Galapagos. In agreement with our genetic results, the overall morphological differences documented by us indicate that the Galapagos material examined is conspecific with T. calverti. In light of this, and following the principle of priority in taxonomic nomenclature, Tramea calverti Muttkowski, 1910 should hereafter be considered a junior synonym of Tramea darwini Kirby, 1889.

scholarly journals Natural variation in social conditions affects male mate choosiness in the amphipod Gammarus roeselii

2021 ◽  
Author(s):  
Konrad Lipkowski ◽  
Sophie Steigerwald ◽  
Lisa M Schulte ◽  
Carolin Sommer-Trembo ◽  
Jonas Jourdan
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Natural Variation ◽  
Natural Populations ◽  
Social Background ◽  
Social Conditions ◽  
Background Information ◽  
Male Mating ◽  
Natural Environments ◽  
Male Mate

Abstract The extent of male mate choosiness is driven by a trade-off between various environmental factors associated with the costs of mate acquisition, quality assessment and opportunity costs. Our knowledge about natural variation in male mate choosiness across different populations of the same species, however, remains limited. In this study, we compared male mate choosiness across 10 natural populations of the freshwater amphipod Gammarus roeselii (Gervais 1835), a species with overall high male mating investments, and evaluated the relative influence of population density and sex ratio (both affecting mate availability) on male mate choosiness. We investigated amplexus establishment after separating mating pairs and presenting focal males with a novel, size-matched female from the same population. Our analysis revealed considerable effects of sex ratio and (to a lesser extent) population density on time until amplexus establishment (choosiness). Male amphipods are able to perceive variable social conditions (e.g., sex ratio) and modify their mating strategy accordingly: We found choosiness to be reduced in increasingly male-biased populations, whereas selectivity increases when sex ratio becomes female biased. With this, our study expands our limited knowledge on natural variations in male mate choosiness and illustrates the importance of sex ratio (i.e., level of competition) for male mating decisions in natural environments. Accounting for variation in sex ratios, therefore, allows envisioning a distinctive variation of choosiness in natural populations and highlights the importance of considering social background information in future behavioral studies.

scholarly journals Natural variation in yolk fatty acids, but not androgens, predicts offspring fitness in a wild bird

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Lucia Mentesana ◽  
Martin N. Andersson ◽  
Stefania Casagrande ◽  
Wolfgang Goymann ◽  
Caroline Isaksson ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Maternal Effects ◽  
Natural Variation ◽  
De Novo ◽  
Natural Populations ◽  
Egg Laying ◽  
Interactive Effects ◽  
Free Living ◽  
Offspring Fitness

Abstract Background In egg-laying animals, mothers can influence the developmental environment and thus the phenotype of their offspring by secreting various substances into the egg yolk. In birds, recent studies have demonstrated that different yolk substances can interactively affect offspring phenotype, but the implications of such effects for offspring fitness and phenotype in natural populations have remained unclear. We measured natural variation in the content of 31 yolk components known to shape offspring phenotypes including steroid hormones, antioxidants and fatty acids in eggs of free-living great tits (Parus major) during two breeding seasons. We tested for relationships between yolk component groupings and offspring fitness and phenotypes. Results Variation in hatchling and fledgling numbers was primarily explained by yolk fatty acids (including saturated, mono- and polyunsaturated fatty acids) - but not by androgen hormones and carotenoids, components previously considered to be major determinants of offspring phenotype. Fatty acids were also better predictors of variation in nestling oxidative status and size than androgens and carotenoids. Conclusions Our results suggest that fatty acids are important yolk substances that contribute to shaping offspring fitness and phenotype in free-living populations. Since polyunsaturated fatty acids cannot be produced de novo by the mother, but have to be obtained from the diet, these findings highlight potential mechanisms (e.g., weather, habitat quality, foraging ability) through which environmental variation may shape maternal effects and consequences for offspring. Our study represents an important first step towards unraveling interactive effects of multiple yolk substances on offspring fitness and phenotypes in free-living populations. It provides the basis for future experiments that will establish the pathways by which yolk components, singly and/or interactively, mediate maternal effects in natural populations.

Locomotion is not influenced by denticle number in larvae of the fruit fly Drosophila melanogaster

2005 ◽  
Vol 83 (2) ◽  
pp. 368-371 ◽  
Author(s):  
Mark J Fitzpatrick ◽  
Evelyn Szewczyk
Keyword(s):  
Drosophila Melanogaster ◽  
Related Species ◽  
Natural Variation ◽  
Fruit Fly ◽  
Fruit Flies ◽  
Negative Effects ◽  
Closely Related Species ◽  
Locomotory Performance ◽  
Locomotion Speed

Denticles are small projections on the underside of larval fruit flies that are used to grip the substrate while crawling. Previous studies have shown that (i) there is natural variation in denticle number and pattern between Drosophila melanogaster (Meigen, 1830) and several closely related species and (ii) mutations affecting denticle morphology have negative effects on locomotory performance. We hypothesized that there would be a correlation between denticle number and locomotory performance within populations of D. melanogaster. Despite finding considerable variation in denticle number, we found no correlation between denticle number and three measurements of larval locomotion: speed, acceleration, and absolute turning rate.

scholarly journals Morphological variation of Cedrela odorata (Meliaceae): contrast between natural and managed populations

2018 ◽  
pp. 157-171 ◽  
Author(s):  
Dulce María Galván-Hernández ◽  
Manuel Alejandro Macedo-Villareal ◽  
Francisco Federico Núñez de Cáceres-González ◽  
Arturo Sánchez-González ◽  
Pablo Octavio-Aguilar
Keyword(s):  
Morphological Variation ◽  
Natural Populations ◽  
Forest Composition ◽  
Cedrela Odorata ◽  
Size Classes ◽  
Factors Analysis ◽  
Height Class ◽  
Lower Height ◽  
Specific Association ◽  
Spanish Cedar

Background and Aims: Cedrela odorata (Spanish cedar) is a tropical tree native to America with an important international trade market. In this study, the morphological variation of C. odorata was compared among three conditions: logging, plantations, and natural populations, with the objective to evaluate the current condition of managed populations after harvesting and in plantations, in contrast to relatively well-preserved populations.Methods: Two sites were chosen for each condition. The population density and four morphological attributes were measured: diameter at breast height, height, angle of branch insertion and crown form. A multivariate approach was used to compare the morphological variation among conditions (generalized discriminant factors analysis) and determine total variation distributed among size classes (cluster analysis), as well as assignment of these classes to each condition (canonical correspondence analysis).Key results: Four significantly different size classes were identified among all populations with specific association to condition. Strongest correlations were between highest trees with natural populations and small trees with plantations. Forest management, including harvesting and plantation conditions, reduced the phenotypical variation and modified the dasometrical attributes of C. odorata. The logging of the better shaped phenotypes increased the smaller size trees frequency compared to commercial size individuals, and changed the forest composition favoring small categories.Conclusions: The forest exploitation generates homogenization in median height-class and the plantation in lower height-class. In both cases, the harvestable trees are scarce, even after 20 years of management; and they are non-existent in plantations of 15 years. These results suggest that the removal of the highest trees, as well as forest plantations, are not being effective to wood production since they do not reach commercial sizes in the time of recovery or projected growth. 

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