A Multi-Institutional Assessment of Factors Influencing Locomotion and Pacing in Captive Okapis (Okapia Jonhstoni)
The okapi (Okapia johnstoni), native to the Democratic Republic of Congo, is a large, solitary, and diurnal forest-dwelling ungulate highly sensitive to captive conditions. The captive population demonstrates persistent health problems, reproductive abnormalities, and several potentially abnormal repetitive behaviors. This study reports on locomotion and pacing in adult male and female okapis. Commonly, data on […]
Giraffe and okapi: Africa’s forgotten megafauna
The Giraffidae family includes only two living species of ungulates: the giraffe (Giraffa camelopardalis) and the okapi (Okapia johnstoni), both restricted to the African continent. Taxonomically, the Giraffa and Okapia genera separated from each other approximately 16 million years ago (Hassanin et al., 2012), and they now exhibit as many differences as similarities. Today Okapia […]
The binucleate cell of Okapi and Giraffe placenta shows distinctive glycosylation compared with other ruminants: A lectin histochemical study
The placenta of ruminants contains characteristic binucleate cells (BNC) with a highly conserved glycan structure which evolved early in Ruminant phylogenesis. Giraffe and Okapi placentae also contain these cells and it is not known whether they have a similar glycan array. We have used lectin histochemistry to examine the glycosylation of these cells in these […]
Large-scale ruminant genome sequencing provides insights into their evolution and distinct traits
The ruminants are one of the most successful mammalian lineages, exhibiting morphological and habitat diversity and containing several key livestock species. To better understand their evolution, we generated and analyzed de novo assembled genomes of 44 ruminant species, representing all six Ruminantia families. We used these genomes to create a time-calibrated phylogeny to resolve topological […]
The giraffe’s long neck : From evolutionary fable to whole organism
A LONE GIRAFFE BULL STOOD at the edge of the scrubby bush forest that opened into a grassland. It was August, the beginning of spring, but also the middle of the dry season in the southern African savannah. The grasses and forbs were yellowed and brittle. Many trees and bushes had no leaves, though some still […]
Understanding selection for long necks in different taxa
There has been recent discussion about the evolutionary pressures underlying the long necks of extant giraffes and extinct sauropod dinosaurs. Here we summarise these debates and place them in a wider taxonomic context. We consider the evolution of long necks across a wide range of (both living and extinct) taxa and ask whether there has […]
The Evolution of the Long-Necked Giraffe (Giraffa camelopardalis L.) – What Do We Really Know? (Part 2)
Introduction: The story which is commonly taught in high schools about the evolution of the long-necked giraffe by natural selection (feeding-competition-hypothesis) fails to explain, among other things, the size differences between males and females. Giraffe cows are up to 1.5 meters shorter than the giraffe bulls, not to mention the offspring. The wide migration range […]
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): […]
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 […]