Adaptive Significance of Post-Hatching Developmental Patterns and Growth Rates in the Alcidae

1973 ◽  
Vol 4 (2) ◽  
pp. 113 ◽  
Author(s):  
Spencer G. Sealy
Keyword(s):  
Growth Rates ◽  
Adaptive Significance ◽  
Developmental Patterns

A Comparison of the Growth of Vertically-Migrating and Nonmigrating Kokanee (Oncorhynchus nerka) Fry

1990 ◽  
Vol 47 (3) ◽  
pp. 486-491 ◽  
Author(s):  
N. T. Johnston
Keyword(s):  
British Columbia ◽  
Vertical Migration ◽  
Growth Rates ◽  
Oncorhynchus Nerka ◽  
Geometric Mean ◽  
Adaptive Significance ◽  
Behavioural Thermoregulation ◽  
Kootenay Lake ◽  
Efficiency Hypothesis

A comparison of the growth of vertically-migrating kokanee (Oncorhynchus nerka) fry and nonmigrating fry confined to the epilimnion in thermally-stratified Kootenay Lake, British Columbia rejected the bioenergetic efficiency hypothesis for the adaptive significance of vertical migration. Growth rates were higher for nonmigrating fry than for vertically-migrating fry. Geometric mean wet weights in early October were 2.88 g for non-migrating fry and 1.40 g for vertically-migrating fry of the same stock. The geometric mean weight of fry of a second stock rearing in the isothermal West Arm, in which behavioural thermoregulation by vertical migration was not possible, was 8.54 g in early October.

Biology of Fire Ephemerals of the Sandplains of the Kwongan of South-Western Australia

1985 ◽  
Vol 12 (6) ◽  
pp. 641 ◽  
Author(s):  
JS Pate ◽  
NE Casson ◽  
J Rullo ◽  
J Kuo
Keyword(s):  
Life Cycle ◽  
Reproductive Biology ◽  
Seedling Growth ◽  
Western Australia ◽  
Growth Rates ◽  
Dry Matter ◽  
Dry Weight ◽  
Growing Season ◽  
Adaptive Significance ◽  
Sexually Dimorphic

The growth, longevity, mineral relationships and reproductive biology of 18 species of fire ephemerals were examined in sclerophyllous shrubland, located mainly within the Jurien : Badgingarra region of the Northern Sandplains of the kwongan of SW. Australia. Ten of the species were monocarpic, completing their life cycle within the 6-8 month winter growing season after a summer or autumn fire. The remaining species were polycarpic, commencing reproduction in their second season and surviving and reproducing for a further two to eight seasons (depending on species). Detailed study was made of growth and dry matter allocation in the dioecious, sexually dimorphic, polycarpic species Tersonia brevipes (Gyrostemonaceae). Monocarpic species tended to produce smaller seeds, and exhibited greater seed output per unit biomass and higher harvest indices for dry matter and minerals than polycarpic species. Certain monocarpic species showed great plasticity in final dry weight, e.g. a 2700-fold difference between largest and smallest individuals in a sample of 250 plants of Stipa elegantissima (Poaceae), and a 180-fold range in a similarly sized sample of Macarthuria apetala (Aizoaceae). The fire ephemerals studied generally exhibited faster seedling growth rates, greater concentrations of P and N (but not of Ca, Mg and K) in seedling dry matter, but usually lesser concentrations of P and N (but not of Ca, Mg and K) in seed dry matter than in cohabiting obligate seeder or sprouter species with potential life spans exceeding 15 years. The above-mentioned features of fire ephemerals are suggested to be of special adaptive significance within the context of exploitation of transiently non-limiting habitat resources immediately following fire.

scholarly journals Anthocyanins Reduce Fungal Growth in Fruits

2008 ◽  
Vol 3 (8) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
H. Martin Schaefer ◽  
Michael Rentzsch ◽  
Michael Breuer
Keyword(s):  
Antifungal Activity ◽  
Growth Rates ◽  
Plant Defence ◽  
Fungal Growth ◽  
Reproductive Organs ◽  
Adaptive Significance ◽  
Fruit Rot ◽  
Vegetative Tissue ◽  
Grape Varieties

As the most visible role of anthocyanins is to impart colors, the adaptive significance of anthocyanins in plant reproductive organs is invariably attributed to the attraction of seed dispersers and pollinators. However, few studies suggested that anthocyanins in vegetative tissue might also function in plant defence, although the evidence for such a function is not particularly strong. Here, we investigated whether anthocyanins contribute to fruit defence against fruit-rot fungi. We found that the risk of fruit-rot in grape varieties infected with Botrytis cinerea decreased with increasing anthocyanin contents. Moreover, anthocyanin contents directly inhibited growth rates of nine fruit-rot fungi on agar plates. Anthocyanins reduced fungal growth by 50% in the concentrations that typically characterise unripe blackberries and by 95% in the concentrations that typify ripe blackberries. We conclude that anthocyanins in fruits not only function to attract animal vectors, but that they also contribute to fruit defence. The antifungal activity of anthocyanins might more widely explain their occurrence in various plant organs such as vegetative tissue and roots.

scholarly journals Growth and Development of Prefledging Canada Geese and Lesser Snow Geese: Ecological Adaptation or Physiological Constraint?

The Auk ◽  
2002 ◽  
Vol 119 (1) ◽  
pp. 221-227 ◽  
Author(s):  
Shannon S. Badzinski ◽  
C. Davison Ankney ◽  
James O. Leafloor ◽  
Kenneth F. Abraham
Keyword(s):  
Growth Rates ◽  
Growth And Development ◽  
Ecological Factors ◽  
Canada Geese ◽  
Adult Size ◽  
Body Parts ◽  
Developmental Patterns ◽  
Snow Geese ◽  
Lesser Snow Geese ◽  
Physiological Constraint

AbstractNeonate, gosling, and adult Canada Geese (Branta canadensis interior) and Lesser Snow Geese (Chen caerulescens caerulescens) were collected to evaluate if growth rates and developmental patterns differed interspecifically and to determine if such differences were better explained by physiology of the growth process or by ecological conditions historically experienced by those two species. Patterns of growth and development of Canada and Lesser Snow goose goslings were similar to those reported for other Arctic geese, but differences in relative growth rates and developmental patterns of external structures, digestive organs, and skeletal muscles were observed between these two species. As compared to Canada Geese, body parts associated with locomotion and acquisition or processing of food generally increased at relatively faster rates and were more developed relative to adult size in Lesser Snow Geese. Relative rates of increase for carcass protein and body mass in these two species did not support a physiological constraint on growth. Rates and patterns of growth and development were better explained as adaptations to ecological factors, such as growing season and nesting or brood rearing conditions, historically experienced by these two species.

Signification adaptative des différents types de développements postembryonnaires chez les Gamasides (Acariens: Anactinotriches)

1987 ◽  
Vol 65 (6) ◽  
pp. 1299-1310 ◽  
Author(s):  
Françoise Athias-Binche
Keyword(s):  
Phenotypic Plasticity ◽  
Postembryonic Development ◽  
Adaptive Significance ◽  
Relative Duration ◽  
Developmental Patterns ◽  
Selection Strategies ◽  
Full Development ◽  
Gamasid Mites ◽  
Embryonic Ectoderm ◽  
Duration Of Development

This review of the adaptive significance of various patterns of postembryonic development in the gamasid mites is restricted to the phenotypic and adaptive aspects of the different developmental patterns. Postembryonic development is redefined as beginning with achievement of embryonic ectoderm differentiation into a sclerified recognizable integument. The various kinds of postembryonic development depend on the ecology of the species and their adaptative strategies, ranging from generalized edaphic forms to more specialized species, either colonizing unpredictable habitats or being parasitic. In relation to progressive specialization, the relative duration of development tends to decrease from four active instars to three or two instars, or even to an abbreviated adult–adult cycle in endoparasitic species. One can distinguish the following main features: full development with four active instars, full development but comprising one or several phoretic instars; abbreviated development, with regressed apomorphic larva, with ovolarviparity, with regressed protonymph or with both regressed protonymph and deutonymph associated with ovolarviparity, and occasionally with phoresy. Phenotypic plasticity may occur and can be marked by facultative, behavioural, or polymorphic phoresy, facultative ovolarviparity, occasional arrhenotoky, or appearance of dormancy. The adaptive fitness of these different characters is discussed in terms of r–K selection strategies, colonizing dynamics, and specialized microhabitats. The concepts of adaptative and evolutive processes are briefly discussed, including Grandjean's theory of "l'évolution selon l'âge."

Presence and development of lignotubers in shrubs of the Chilean matorral

1983 ◽  
Vol 61 (6) ◽  
pp. 1804-1808 ◽  
Author(s):  
Gloria Montenegro ◽  
Guacolda Avila ◽  
Peter Schatte
Keyword(s):  
Leaf Area ◽  
Growth Rates ◽  
Adaptive Significance ◽  
Shrub Species ◽  
Central Chile ◽  
Chilean Matorral ◽  
Area Growth ◽  
Leaf Area Growth

The development of lignotubers was analyzed in seedlings of representative shrub species of the matorral in central Chile. The lignotuber is evident 3 months after germination in Cryptocarya alba and 4–5 months after germination in Colliguaya odorifera, Satureja gilliesii, and Lithraea caustica. Top removal in adult specimens soon produced formation of shoots as a result of the activation of the root-crown buds. The leaf area growth rates of shoots arising from lignotubers are significantly higher than those of seedlings and normally growing shrubs. The adaptive significance of lignotubers in matorral shrubs is discussed.

scholarly journals Absolute axial growth and trunk segmentation in the early Cambrian trilobite Oryctocarella duyunensis

Paleobiology ◽  
2021 ◽  
pp. 1-16
Author(s):  
Tao Dai ◽  
Nigel C. Hughes ◽  
Xingliang Zhang ◽  
Giuseppe Fusco
Keyword(s):  
Growth Rates ◽  
Early Cambrian ◽  
Phase Growth ◽  
Developmental Patterns ◽  
Cambrian Trilobite ◽  
Determinate Growth ◽  
Western Hunan ◽  
Axial Growth ◽  
Size Data ◽  
Stratigraphic Interval

Abstract A short stratigraphic interval near Bulin in western Hunan (China) yields multiple specimens of the ~514-Myr-old oryctocarine trilobite Oryctocarella duyunensis. Size data obtained from these specimens indicate that, from meraspid degree 1 onward, degrees represent successive instars. Meraspid growth persisted until a terminal stage was reached, providing the first example of determinate growth in trilobites and, notably, in an early Cambrian species. The sample contains three varieties of such terminal stages, recognized as holaspids, with 9, 10, or 11 thoracic segments, respectively. During the meraspid phase, growth rates were not constant in this species. The pattern of growth seen in the Bulin assemblage differs modestly from that reported in the same species from two other localities, attesting to microevolutionary variation in developmental patterns among these collections.

Do Children With Developmental Language Disorder (DLD) Have Difficulties With Interference Control, Visuospatial Working Memory, and Selective Attention? Developmental Patterns and the Role of Severity and Persistence of DLD

2020 ◽  
Vol 63 (9) ◽  
pp. 3036-3050
Author(s):  
Elma Blom ◽  
Tessel Boerma
Keyword(s):  
Working Memory ◽  
Selective Attention ◽  
Language Disorder ◽  
Typically Developing ◽  
Developmental Language Disorder ◽  
Visuospatial Working Memory ◽  
Interference Control ◽  
Developmental Patterns ◽  
Search Tasks ◽  
The Impact

Purpose Many children with developmental language disorder (DLD) have weaknesses in executive functioning (EF), specifically in tasks testing interference control and working memory. It is unknown how EF develops in children with DLD, if EF abilities are related to DLD severity and persistence, and if EF weaknesses expand to selective attention. This study aimed to address these gaps. Method Data from 78 children with DLD and 39 typically developing (TD) children were collected at three times with 1-year intervals. At Time 1, the children were 5 or 6 years old. Flanker, Dot Matrix, and Sky Search tasks tested interference control, visuospatial working memory, and selective attention, respectively. DLD severity was based on children's language ability. DLD persistence was based on stability of the DLD diagnosis. Results Performance on all tasks improved in both groups. TD children outperformed children with DLD on interference control. No differences were found for visuospatial working memory and selective attention. An interference control gap between the DLD and TD groups emerged between Time 1 and Time 2. Severity and persistence of DLD were related to interference control and working memory; the impact on working memory was stronger. Selective attention was unrelated to DLD severity and persistence. Conclusions Age and DLD severity and persistence determine whether or not children with DLD show EF weaknesses. Interference control is most clearly impaired in children with DLD who are 6 years and older. Visuospatial working memory is impaired in children with severe and persistent DLD. Selective attention is spared.

Sign in / Sign up

Export Citation Format

Share Document