Topic
Primate
About: Primate is a research topic. Over the lifetime, 1250 publications have been published within this topic receiving 67388 citations. The topic is also known as: the primate order & primates.
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TL;DR: There was evidence that the appendix vermiformis began to develop in certain Old World monkeys and became fully developed in the anthropoid apes, showing that, far from being a vestigial organ, it has actually developed progressively in primates.
Abstract: The examination of the caecum of two groups of cynomolgus and rhesus monkeys, two orang-utans and a chimpanzee, as well as an extensive review of the available literature, confirmed that the length of the caecum, relative to that of the colon, decreased as the position of the species in the primate scale rose. Although absent in prosimians and New World monkeys, there was evidence that the appendix vermiformis began to develop in certain Old World monkeys and became fully developed in the anthropoid apes, showing that, far from being a vestigial organ, it has actually developed progressively in primates.
33 citations
TL;DR: The degree of neocorticalization varied in different taxa, greatest in primates and least in marsupials in the sample measured here, based on measurements in over 100 endocranial casts from many different orders of mammals, including 10 living species.
Abstract: Mammalian neocortex became relatively a larger fraction of the brain in mammals as they evolved during the Cenozoic era, the past 65 million years. The evolution of neocorticalization is measured by changes in the ratio of the surface area of neocortex to the surface area of the whole brain. Neocorticalization occurred to different extents in different lineages. The overall increase is evident in the positive slope of the regression of neocortical ratio on geological age. The degree of neocorticalization varied in different taxa, greatest in primates and least in marsupials in the sample measured here. The extent of human neocorticalization is not unique for a primate. At least one monkey, a mangabey (Cercocebus), measured as slightly more neocorticalized although the difference between the human and monkey endocasts in this sample was very small. All of the anthropoid primates, including an australopithecine, were very similar in their measurements. These conclusions are based on measurements in over 100 endocranial casts (endocasts) from many different orders of mammals, including 10 living species.
33 citations
TL;DR: The data suggest that 2 functionally distinct pRNases have been selected for in the colobine monkeys, with one group adapting to the role of a digestive enzyme by evolving at an increased rate with loss of positive charge, namely arginine residues.
Abstract: Unique among primates, the colobine monkeys have adapted to a predominantly leaf-eating diet by evolving a foregut that utilizes bacterial fermentation to breakdown and absorb nutrients from such a food source. It has been hypothesized that pancreatic ribonuclease (pRNase) has been recruited to perform a role as a digestive enzyme in foregut fermenters, such as artiodactyl ruminants and the colobines. We present molecular analyses of 23 pRNase gene sequences generated from 8 primate taxa, including 2 African and 2 Asian colobine species. The pRNase gene is single copy in all noncolobine primate species assayed but has duplicated more than once in both the African and Asian colobine monkeys. Phylogenetic reconstructions show that the pRNase-coding and noncoding regions are under different evolutionary constraints, with high levels of concerted evolution among gene duplicates occurring predominantly in the noncoding regions. Our data suggest that 2 functionally distinct pRNases have been selected for in the colobine monkeys, with one group adapting to the role of a digestive enzyme by evolving at an increased rate with loss of positive charge, namely arginine residues. Conclusions relating our data to general hypotheses of evolution following gene duplication are discussed.
33 citations
TL;DR: Mountain gorillas were unique among anthropoids in the high proportion of milk 20:4n-6, which seems to be unrelated to requirements of a larger brain and may instead reflect species-specific metabolic processes or an unknown source of this fatty acid in the mountain gorilla diet.
Abstract: Fatty acids in milk reflect the interplay between species-specific physiological mechanisms and maternal diet. Anthropoid primates (apes, Old and New World monkeys) vary in patterns of growth and development and dietary strategies. Milk fatty acid profiles also are predicted to vary widely. This study investigates milk fatty acid composition of five wild anthropoids (Alouatta palliata, Callithrix jacchus, Gorilla beringei beringei, Leontopithecus rosalia, Macaca sinica) to test the null hypothesis of a generalized anthropoid milk fatty acid composition. Milk from New and Old World monkeys had significantly more 8:0 and 10:0 than milk from apes. The leaf eating species G. b. beringei and A. paliatta had a significantly higher proportion of milk 18:3n-3, a fatty acid found primarily in plant lipids. Mean percent composition of 22:6n-3 was significantly different among monkeys and apes, but was similar to the lowest reported values for human milk. Mountain gorillas were unique among anthropoids in the high proportion of milk 20:4n-6. This seems to be unrelated to requirements of a larger brain and may instead reflect species-specific metabolic processes or an unknown source of this fatty acid in the mountain gorilla diet.
33 citations
01 Jan 2010
TL;DR: The authors divided living primates into two groups, the strepsirrhines (lemurs and lorises) and the haplorrhine (monkeys, apes, and tarsiers).
Abstract: Introduction The primates comprise a diverse group of eutherian mammals, with between some 200 and 400 species, depending on the taxonomic authority consulted (e.g., Corbet & Hill, 1991; Wilson & Reeder, 2005). Most of these species dwell in tropical forests, but primates also thrive in many other habitats, including savannas, mountainous forests of China and Japan, and even some urban areas. Living primates are divided into two groups, the strepsirrhines (lemurs and lorises) and the haplorrhines (monkeys, apes, and tarsiers). Strepsirrhines include mostly arboreal species and retain several ancestral characteristics, including greater reliance on smell and (in most species) a dental comb that is used for grooming. Most are nocturnal, but some have, in parallel with most haplorrhines, evolved a diurnal niche. They are found only in the Old World tropics. Haplorrhines are more widely distributed geographically, being found in both the New and Old Worlds. They include two groups, the platyrrhines and the catarrhines. Platyrrhines are monkeys native to the New World. Catarrhines include both Old World monkeys and apes. With the exception of owl monkeys in the genus Aotus , all monkeys and apes are active during the day (i.e., diurnal), and most live in bisexual social groups that vary in size from 2 to well over 100 adults (Smuts, Cheney, Seyfarth, et al., 1987). Nonhuman primates are among the best-studied of mammals, in large part because of their close phylogenetic relatedness to humans.
32 citations