Species variations in the foetal growth rates of eutherian mammals

Frazer, J. F. D.; Huggett, A. St. G.

doi:10.1111/j.1469-7998.1974.tb03173.x

Cited by 55 publications

(20 citation statements)

References 12 publications

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“…Because embryos often experience a time lag ( t 0 ) in growth at the beginning of the development period, the power function sometimes appears as M = a ( t − t 0 ) b . The exponent b typically assumes a value close to 3 (Huggett & Widdas 1951; Frazer & Huggett 1974); that is, mass increases approximately as the cube of time. A diagnostic for the goodness of fit of the power function is ln(dln M /d t ) = ln b − ln( t − t 0 ), according to which the logarithm of the exponential growth rate decreases linearly with age.…”

Section: Introductionmentioning

confidence: 99%

“…Rate of development is a fundamental component of the life histories of organisms. Although postnatal growth rate of vertebrates has received considerable attention as a life-history parameter (Case 1978;Zullinger et al 1984;Starck & Ricklefs 1998a), relatively less information is available for the relatively inaccessible embryo period (Frazer & Huggett 1974;Ricklefs 1987Ricklefs , 2006. Development is closely connected to longevity, with respect to both correlations across evolutionary lineages (Promislow 1991;Ricklefs & Scheuerlein 2001;Metcalfe & Monaghan 2003;Ricklefs 2006;De Magalhaes, Costa & Church 2007) and environmental effects of early conditions on later life (Barker & Martyn 1992;Desai & Hales 1997;Jennings et al 1999;Osmond & Barker 2000;Metcalfe & Monaghan 2001;Schwartz & Morrison 2005).…”

Section: Introductionmentioning

confidence: 99%

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Embryo growth rates in birds and mammals

Ricklefs¹

2010

Functional Ecology

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Summary1. Embryo mass growth curves of 36 species of bird and 18 species of mammal were fitted by sigmoidal Gompertz functions, in which k (days )1 ) describes the rate at which the embryo approaches an asymptotic mass A (g).2. The parameters of the Gompertz function were uncorrelated with parameters of power functions fitted to the same growth data, indicating that the two models describe different aspects of growth.3. Asymptotes of the Gompertz functions for embryonic growth averaged 2AE5 times neonate size, but were well below adult mass. Thus, the pre-and postnatal phases of growth are distinct and have different target sizes. 4. Embryo growth rate (k) decreases as the )1 ⁄ 4 power of neonate size; values for mammals were 63% of those of birds, on average. 5. Embryo growth rate can be predicted solely by the length of the incubation or gestation period, regardless of the size of the neonate, with the same relationship for birds and mammals. 6. Postnatal growth rate (k G ) scales linearly with embryonic growth rate (k), but is nearly fivetimes more rapid, on average, in birds than in mammals. k G and k have similar magnitude in birds, but k G is relatively much slower than k in mammals. 7. Rate of actuarial senescence x (year )1 ), measured by the increase in mortality rate with age, is positively related to the rate of embryo growth in both birds and mammals, but is higher in the latter. Moreover, rate of ageing in birds is uniquely related to embryo growth while that in mammals is uniquely related to postnatal growth rate. Thus, development and ageing appear to be differently connected in birds and mammals, although the basis for these relationships is not known.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Embryo growth rates in birds and mammals

Ricklefs¹

2010

Functional Ecology

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“…Size differences at birth presumably reflect either an underlying difference in foetal specific growth rate or gestation time. In fact, there is a consistent relationship between size at birth, foetal specific growth rates and gestation time among vertebrates (Huggett & Widdas, 1951;Frazer & Huggett, 1974;Frazer, 1977;Millar, 1977Millar, , 1981Calder, 1982). Foetal specific growth rates are remarkably constant among terrestrial mammal species within the same taxonomic order and, as a result, the length of the gestation period in large part determines neonate size: canid species with shorter gestation times generally have smaller neonates (Fig.…”

Section: Growth Gestation Time and Comparative Morphology Of Canidmentioning

confidence: 97%

Developmental constraints on limb growth in domestic and some wild canids

Wayne

1986

Journal of Zoology

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The domestic dog varies remarkably in limb size. Presumably, such differences in limb size stem from inequities in postnatal specific growth rate. I test this hypothesis by examining the postnatal growth of limb bones (40–250 days post‐partum) in four dog breeds of dramatically different adult size; Lhasa Apso, Cocker Spaniel, Labrador Retriever and Great Dane. The results show that the limb bones of these four breeds have similar specific growth rates throughout most of postnatal development. Thus, proportionate differences in limb bone length are established during perinatal growth (0–40 days post‐partum) or before birth. Comparisons of postnatal growth in the Great Dane and two wild canids of dramatically different leg length, the Bush dog (Speothos venaticus) and the Maned wolf (Chrysocyon brachyurus) also show a near congruency of specific growth rate curves. However, despite these similarities, the adult limb proportions of small dogs and small wild canids are different. Dogs also differ from wild canids in the relative variability of gestation time. All dogs have a similar gestation period of 60–63 days which is independent of birth weight, whereas the two are directly related in wild canids. I suggest that small dogs may differ in limb proportions from small wild canids because the latter have a shorter gestation period. Thus, the relative invariability of gestation time in domestic dogs may act as a fundamental constraint on their morphologic variability.

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“…Nutrient intake in newly-born mammals varies not only with the volume of milk, but also with its fat content, so that growth rates after birth vary from one species to another, just as much as the specific foetal growth rates do (see Frazer & Huggett, 1974). Recent figures for the rat (Rattus norvegicus) show that while growth before birth is by a linear daily increase in length or in cube root of foetal weight, after birth and through weaning there is an equally steady daily increase in actual weight of the young (Frazer, 1977).…”

Section: Introductionmentioning

confidence: 99%

“…In the latter, it has been shown (Huggett & Widdas, 1951) that plotting the cube root of foetal weight against time gives a linear growth plot. There is initial slow growth related to the time when the yolksac placenta is active, but once the chorio-allantoic placenta is functional, the slope of the second line is markedly steeper . Frazer & Huggett (1974) showed that this specific foetal growth rate varies considerably between species, the bats and primitive primates having values ranging from as low as 0.01 or 0-02, while the sea-cows go as high as 0.2, with seals from 0.08 to 0.15 and the cetaceans as high as 0-58 for the blue whale.…”

Section: Introductionmentioning

confidence: 99%

Growth of young vertebrates in the egg or uterus

Frazer

1977

Journal of Zoology

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In eutherian mammals, foetal growth shows a straight‐line relationship between time and cube root of foetal weight. The same relationship has now been found to hold for the embryos in birds' eggs and is postulated for reptiles. In marsupials the specific foetal growth rate does not exceed that already known for the higher primates. Outside the eutherian mammals, only the birds have developed high embryonic growth rates, but in exchange for other disadvantages.

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Species variations in the foetal growth rates of eutherian mammals

Abstract: While the larger cetaceans have the greatest known specific foetal growth rates (Huggett & Widdas, 1951), examination has shown that among land mammals of a particular Order, Sub‐order or even Genus, there may be marked variation in rates.

Cited by 55 publications

References 12 publications

Embryo growth rates in birds and mammals

Embryo growth rates in birds and mammals

Developmental constraints on limb growth in domestic and some wild canids

Growth of young vertebrates in the egg or uterus

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