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Giraffe Cardiovascular Adaptations to Gravity

The physiological systems of animals have adapted to Earth’s gravity over the past hundreds of millions of years. In general, gravitational adaptations of the cardiovascular system are more pronounced in terrestrial specieswith greater height and thus greater gravity-dependent gradients of blood pressure from head to feet. For example, dinosaurs (1), tree-climbing snakes (2), giraffes (3), and other tall animals have evolved mechanisms to provide adequate blood flow and nutrition to their brains while restricting blood flow and tissue swelling in

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Matrilineal population structure and distribution of the Angolan giraffe the Namib desert and beyond

The distribution maps of giraffe (Giraffa) subspecies in southern Africa are based on historical assumptions, yet some populations have likely been misidentified, hindering effective conservation efforts. Particularly, the populations in Zimbabwe are poorly studied, and translocations, such as the 1991 movement of giraffe from Namibia’s Etosha National Park to mitigate the human-induced decline of Namibia’s desert-dwelling giraffe in the lower Hoanib and Hoarusib Rivers, was concluded without consideration of genotype. Mitochondrial DNA sequence analyses from cytochrome b and control region

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The giraffe’s neck: another icon of evolution falls

The giraffe is a major problem for Darwinism for many reasons. No evidence exists in the fossil record for giraffe evolution, nor are evolutionists able to explain why the giraffe’s neck evolved. The most common Darwinian explanation for giraffe neck evolution—the advantage a long neck gave in reaching leaves high in trees for food—is now recognised by evolutionists as likely incorrect, and as a result many other ad hoc explanations have been proposed. Many writers either are unaware of (or

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Seeing spots: quantifying mother-offspring similarity and assessing fitness consequences of coat pattern traits in a wild population of giraffes (Giraffa camelopardalis)

Polymorphic phenotypes of mammalian coat coloration have been important to the study of genetics and evolution, but less is known about the inheritance and fitness consequences of individual variation in complex coat pattern traits such as spots and stripes. Giraffe coat markings are highly complex and variable and it has been hypothesized that variation in coat patterns most likely affects fitness by camouflaging neonates against visually hunting predators. We quantified complex coat pattern traits of wild Masai giraffes using image

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How giraffes prevent oedema

An upright giraffe, by analogy with humans, ought to suffer massive oedema in its feet; moreover, when it lowers its head to drink, the blood should rush down into it and be unable to flow up again. New pressure measurements reported on page 59 of this issue by Hargens et al. Show why neither of these things happens, and also contain some surprising observations of highly variable venous pressure (P.) in the leg and of a counter-gravitational gradient of P.

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Giraffe Thermoregulation: a review

The ability to maintain a relatively constant body temperature is central to the survival of mammals. Giraffes are found in relatively hot rather than cold environments, have a body temperature of 38.5 ± 0.5°C, and must have evolved appropriate thermoregulatory mechanisms to maintain this temperature and to survive in their chosen habitats. Their thermoregulation depends on anatomical features and behavioural and physiological mechanisms. To minimize physiological thermoregulation giraffes orientate their bodies to optimize radiant heat gain and to maximize convective

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From Fetus to Adult—An Allometric Analysis of the Giraffe Vertebral Column

As mammalian cervical vertebral count is almost always limited to seven, the vertebral column of the giraffe (Giraffa camelopardalis) provides an interesting study on scaling and adaptation to shape in light of these constraints. We have defined and described the growth rates of the lengths, widths, and heights of the vertebrae from fetal through neonatal life to maturity. We found that the disproportionate elongation of the cervical vertebrae is not a fetal process but occurs after birth, and that each

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The giraffe (Giraffa camelopardalis) cervical vertebral column: a heuristic example in understanding evolutionary processes?

The current study considers the osteological morphology of the giraffe (Giraffa camelopardalis) vertebral column, with emphasis on evaluating both the adaptive and constraining features compared with other ungulates as a heuristic example in understanding evolutionary processes. Vertebral columns of giraffes varying in age from calf to adult were studied in order to understand the potential evolutionary scenarios that might have led to the modern phenotype. Data from the giraffe sample were then compared with the results from several other ungulate

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White giraffes: The first record of vitiligo in a wild adult giraffe

Variation in the colour and patterning of animal coats has evolved to offer individuals adaptive advantage and is determined by both genetics and environmental factors. The biological functions of animal coat patterns include protection of the skin from exposure to sunlight, protection from predators by camouflage, individual recognition and sexual recognition within a species. Optimal coat patterns are especially important in the wild where immediate survival relies on an individual’s ability to avoid predators. Changes in coat colour within an

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