What Do Monkeys and Apes Have in Common?
There are some interesting traits that monkeys and apes share in common, and this article will examine some of these similarities. They are related to each other in many ways, including Opposable thumbs, sexual promiscuity, and alloparenting. But, is there any genetic similarity between the two species? Luckily, the answer is a resounding “yes!”
Alloparenting between squirrel monkeys and other apes is an important social behavior, and is known to be genetically prevalent in a variety of species. In some species, infants spend up to 30% of their time with their allomother, and allomothers are often young adults who lost their own young early in the year. However, infant swapping behavior has not been documented in the Saimiri, or other species with no known alloparents. In contrast, juvenile females of C. apella regularly leave their infants with their dominant male.
This alloparenting behavior is related to increased neurogenesis in the subventricular zone and enhanced spatial learning-dependent foraging skills in the pups. These studies, involving multiple species, highlight the potential benefits of alloparenting in both human infants and apes. However, these findings may not apply to human babies. For now, further studies are needed to test the effect of alloparenting in humans.
Humans and some apes have opposable thumbs. They use their opposable thumbs for various tasks like throwing or swinging. Their opposable thumbs also help them fish, as they have long digits and forepaws on which to grasp objects. In contrast, the thumbs of other mammals are not opposable. In humans, opposable thumbs are advantageous as they allow them to hold objects with their digits and avoid suffocating themselves.
Old world monkeys and squirrel monkeys have opposable thumbs. These animals are also arboreal, which allows them to use their thumbs to grasp branches and other objects. The colobus monkey does not have opposable thumbs, but other species in the lemur family have these hands and use them to grasp tree branches. These animals can climb trees using their thumbs and their prehensile tails.
Studies have revealed that sexual promiscuity among apes and squirrel monkeys differs largely in group size. This is partly due to the size of the male testis, which is a reliable predictor of promiscuity. However, there was an unknown factor responsible for the differences in group size. Using data from other species of the same genus, researchers imputed values for this variable.
A new study reveals that the females of the Yellow-breasted Capuchin are more sexually active than their male counterparts. The two species share a tendency to have long and narrow sperm sacs, and males have longer follicles. Both species are arboreal, although they can sometimes descend to the ground. These creatures live in groups of 12 to 100 members. The numbers of these troops may be as high as 500.
Female sexual promiscuity is not necessarily associated with greater sex prowess. This may be because of the high risk of sexually transmitted disease. However, the increased risk of STDs may have been a driver for the evolution of the immune system in apes. Nevertheless, it is important to note that this study has some limitations. One limitation is that the genes included in the study were not directly involved in the immune response to STDs.
The genetic similarity between squirrel monkeys and apex apes is based on a DNA panel analyzed from 32 individuals. The genetic variation consists of 382 Alu insertions, varying from 2% to 8% divergence from consensus sequences. There are 110 Alu insertion polymorphisms in the panel, with 35 in the Saimiri and 75 in the NWM subspecies. The other 13 Alu subspecies lacked polymorphic insertions.
To calculate the percentages, geneticists have developed methods to determine the similarities between humans and chimpanzees. The 1.2% chimp-human difference is due to substitutions in the base building blocks of genes. A comparison of the complete genome shows that the differences between humans and chimpanzees also contain duplications and deletions. These changes add up to four to 5% of the human genome difference.
Jessica Watson is a PHD holder from the University of Washington. She studied behavior and interaction between squirrels and has presented her research in several wildlife conferences including TWS Annual Conference in Winnipeg.