The evolution of the long-necked giraffe (Giraffa camelopardalis L.) – What do we really know? (Part 1)
In the following article the assertions of three supporters of the synthetic theory concerning the evolution of the long-necked giraffe will be discussed: the statements of Ulrich Kutschera, Richard Dawkins and Kathleen Hunt. Ulrich Kutschera made the following statement regarding the origin of the giraffe, on 29 November 2005 in 3SAT (a German TV channel): […]
A comparative approach for species delimitation based on multiple methods of multi-locus DNA sequence analysis: A case study of the genus Giraffa (Mammalia, Cetartiodactyla)
Molecular data are now commonly used in taxonomy for delimiting cryptic species. In the case of giraffes, which were treated as a single species (Giraffa camelopardalis) during half of a century, several molecular studies have suggested a splitting into four to seven species, but the criteria applied for taxonomic delimitation were not fully described. In […]
The cervical anatomy of Samotherium, an intermediate-necked giraffid
Giraffidae are represented by many extinct species. The only two extant taxa possess diametrically contrasting cervical morphology, as the okapi is short-necked and the giraffe is exceptionally long-necked. Samotherium major, known from the Late Miocene of Samos in Greece and other Eurasian localities, is a key extinct giraffid; it possesses cervical vertebrae that are intermediate […]
Giraffe genome sequence reveals clues to its unique morphology and physiology
The origins of giraffe’s imposing stature and associated cardiovascular adaptations are unknown. Okapi, which lacks these unique features, is giraffe’s closest relative and provides a useful comparison, to identify genetic variation underlying giraffe’s long neck and cardiovascular system. The genomes of giraffe and okapi were sequenced, and through comparative analyses genes and pathways were identified […]
Organization of cholinergic, putative catecholaminergic and serotonergic nuclei in the diencephalon, mibrain and pons of sub-adult male giraffes
The current study describes the nuclear organization and neuronal morphology of the cholinergic, putative catecholaminergic and serotonergic systems within the diencephalon, midbrain and pons of the giraffe using immunohistochemistry for choline acetyltransferase, tyrosine hydroxylase and serotonin. The giraffe has a unique phenotype (the long neck), a large brain (over 500 g) and is a non-domesticated […]
Observations on the giraffe central nervous system related to the corticospinal tract, motor cortex and spinal cord: what difference does a long neck make?
The mammalian corticospinal tract is known to contain axons that travel from the cerebral cortex to various levels of the spinal cord and its main function is thought to be the mediation of voluntary movement. The current study describes neuroanatomy related to the corticospinal tract of the giraffe. This animal presents a specific morphology that […]
Necks for sex: sexual selection as an explanation for sauropod dinosaur neck elongation
The immensely long neck of a sauropod is one of the most familiar and striking of anatomical specializations among dinosaurs. Here, I use recently collected neontological and paleontological information to test the predictions of two competing hypotheses proposed to explain the significance of the long neck. According to the traditional hypothesis, neck elongation in sauropods […]
Growth patterns and masses of the heads and necks of male and female giraffes
We have analyzed the growth patterns of the head and neck of 65 male and 71 female giraffes from two different populations of giraffes, and also the dimensions of 19 different components of the head and neck in 8 female and 13 male giraffes, to establish if they showed sexual dimorphism and if sexual selection […]
Supplement on the paper of: Extensive population genetic structure in the giraffe.
Brown et al. (pp. 63/64, if I counted correctly, – the page numbers on the PDF of the paper are “not for citation puposes”) suggest “that the giraffe might represent more than one species” and that their results and arguments “support viewing the giraffe as containing multiple distinct species rather than a single polymorphic form. […]
The taxonomic history of giraffe – a brief review
The giraffe has long been considered a single species, albeit highly polymorphic. Its high degree of geographically structured phenotypic variation has lead to 27 recorded specific or subspecific taxon names. This article briefly reviews the significant episodes in the complex taxonomic history of the giraffe.