Our Primate Family Tree
Following our second module, which focused on primate evolution and contemporary primates, students were asked to submit a short essay reflecting on an aspect of primate lifestyles, behavior or culture that helps us better understand our own origins as humans. Below are some excerpts from student essays, published with student permission.
Language and Communication
“Non-human primates use sound to connect with other members of their group, warn of possible danger, claim territory, as well as a variety of other reasons. These sounds or calls have distinctions that allow other members to understand their meanings and react appropriately. Some might correlate to signs of dominance while others can be used to signal locations of other members of the group or provide information on possible threats or dangers…..The ability of primates to use signals in order to identify certain objects or dangers is an example of “semantic communication” (Shook 215).
This is a trait that researchers only thought to exist in humans, but instead is another area of comparison that connects us to non-human primates.
These similarities and differences allow researchers to observe the ways in which evolution shaped the human language and the extents to which we adapted.” — Excerpt from essay by Abby Ulm
“When examining the evolution of human behavior throughout the years, one of the most surprising changes in our society has been the way we communicate with one another. Due to major technological advancements, humans have miraculously invented new forms of communication that we engage in every single day whether it is through texts, emails, or evensocial media posts.
For primates specifically, there are four different ways to communicate with one another: vocal, visual, olfactory, and tactile….
According to the book Primate Communication: A Multimodal Approach, primates use communication to help, “solve the problem of survival, reproduction, and (often) living in groups” (Liebal et al. 22)….. After reexamining all of these forms of communication, the biggest takeaway was unquestionably how much humans have evolved from primates. Rather than simply use these four forms of communication, our evolutionary history has helped us to form so many new forms to help us survive and thrive.” — Excerpt from essay by Jackson Lindner
Citations: Liebal, Katja, et al. Primate Communication: A Multimodal Approach. Cambridge University Press, 2014.
“Looking back on our history and other species’ history, we have learned about nonverbal communication through the lenses of animals that cannot speak. While researching this, many aspects of our evolutionary history have been connected to older primates’ past including chimpanzees.
Hand movements and symbols are a big part of human communication, especially for people who don’t have the ability to actually speak, including people who are deaf or mute.
When studying nonverbal communication it was found that “Such semantic communication, which involves the systematic use of signals to refer to objects in the environment, was once believed to be unique to humans. It may be a precursor to the symbolic capacities of human language” (Jaffe, 215). Before researchers knew about past primate communication, they believed that primates took after our own communication but now we know that it is the other way around. Since primates never physically talked to each other, they had to develop new ways of communicating which included the use of their hands and bodies.” — Excerpt from anonymous essay
Citations: Jaffe, Karin Enstam. “Primate Behavior and Ecology.” Explorations: An Open Invitation To Biological Anthropology, edited by Beth Shook et al., pp. 190–232.
Teaching
“Through observational learning, primates teach their young how to complete tasks learned many generations ago just as humans do.
Observational learning demonstrates a key component in the development of humans that can be traced back to the way that primates teach their own young…..
One way that primates and humans both use teaching is through observing someone complete a task. Human babies learn through observation because they do not understand the human language yet. Primates such as orangutans also cannot vocally teach everything to each other, so they must observe others….. By the use of teaching, humans and primates are able to know what to do in situations that they may have never experienced themselves — also known as cumulative culture.” — Excerpt from essay by Bella Nadeau
Mental Health
“Chimpanzees, like us, are naturally social and gravitate towards forming supportive relationships. They need a strong and supportive community to help maintain the proper amount of affection, emotional support, and physical contact needed to live a happy, healthy, and fulfilled life. After observing the way chimps selflessly interact with one another, Goodall has confirmed that chimps do have the mental capacity for empathy. For example, they share without having selfish motivations. They have the mental capability to understand how other chimps might be feeling and are also able to consider how their actions might emotionally affect other chimps before performing said action. Therefore, chimpanzees experience emotions far more intensely than many people think. They severely suffer mentally and sometimes even physically from lack of reassurance and love. They will visibly appear lifeless, and their eyes will look as hopeless as a depressed human’s eyes would…..
This explains why humans appear motionless, lethargic, hopeless, and depressed after any degree of confinement.
Covid made a lot of people realize the major negative impact that solitary confinement has on human mental health, but before that many people didn’t believe in it.” — Excerpt from essay by Bella Nadeau
Citation: Goodall, Jane. “A Plea for the Chimps.” The New York Times Magazine, 17 May 1987.
Territoriality
“Throughout time, a wide variety of different primates learned to adapt and share new land with one another. Community ecology has evolved slowly over the course of many years… Sympatric communities contain two species that occupy one geographic area, while allopatric communities don’t have overlapping geographic areas with other species. When in danger or a stringent situation, humans and primates find themselves with more aggression and territorialism. When they interact with their own ‘families’ or ‘communities,’ they present themselves as nurturing and loving. This is caused by the range of different communities that occur in both humans and primates. The family/community dynamic within humans and primates show that they will prioritize those who they are close with over other communities.” — Excerpt from essay by Dawson Pfaffman
Citations:
Jaffe, Karin E. “Chapter 6: Primate Behavior and Ecology.” Explorations: An Open Invitation To Biological Anthropology, American Anthropological Association, 2019, pp. 196–202.
Kemper, Steve. “Humans Would Be Better Off If They Monkeyed Around Like The Marquis.” Smithsonian Magazine, September 2013, https://www.smithsonianmag.com/science-nature/humans-would-be-better-off-if-they-monkeyed-around-like-the-muriquis-833014/. Accessed 15 October 2021.
Sleep Patterns
“Chimpanzees in Uganda ha[ve] become nocturnal to avoid conflict with humans and by doing so, this group of chimpanzees has set the precedent that the usually diurnal great apes can adapt to nocturnality to avoid conflict with other animals, especially humans (1:19–2:11)…. It would seem that nocturnality is rare amongst primates, but interestingly enough, even though the sister orders to Primates are exclusively diurnal, nocturnality seems to be the norm amongst more basal primates (most strepsirrhines and tarsiiformes). The question is, why nocturnality? I believe it is due in part to interspecies competition, where members of one species compete with those of another for resources, and also to niche partition, where species adopt different lifestyles from each other to avoid such conflict… In 2014, researchers at Kibale National Park studied the habits of chimpanzees that were living on the edge of the reserve and found that “Contrary to [the primatologists’] expectations, large parties are engaged in crop-raids. . . More surprisingly chimpanzees were crop-raiding during the night” (Krief et al.).
….In other words, human encroachment has led to drastic shifts in the behavior of chimpanzees, a prime example of interspecies conflict….
Instead of shifting their behavior to avoid conflict with other chimpanzee troops (intraspecies conflict), the Kibale chimps were changing their behavior to cope with the encroachment by local corn (maize) farmers (interspecies conflict).” — Excerpt from essay by Harley Bailey
Citations:
“Bigfoot: a Nocturnal Primate.” YouTube, uploaded by Bob Gymlan, 8 Aug. 2016. https://www.youtube.com/watch?v=fOoppTsMZyg. Accessed 4 Oct. 2021
Krief, Sabrina et al. 2014. “Wild Chimpanzees On The Edge: Nocturnal Activities in Croplands”. PLoS ONE 9(10):e109925
Morality & Sexuality
“The insight gained from studying animals like the capuchin monkeys is critical to consider when addressing human societal issues surrounding equality and sexual freedom… Capuchins, like humans, appear to be quite socially complex…. Keith Chen, an economist at UCLA, conducted a study that involved teaching capuchin monkeys the value of currency to observe their responses to various economic phenomena relative to humans. Eventually, the capuchins caught on and successfully traded their lab currency for various kinds and amounts of Jell-O and grapes (Dubner and Levitt). One day, while observing the monkeys, Chen noticed “the first observed exchange of money for sex in the history of monkeykind” (Dubner and Levitt). Some question if the researchers could have known if the monkeys had a clear understanding of the money for sex equation that results in prostitution. The study involving capuchin monkey prostitution may be one of the most applicable to understanding human behavior. While it may not be an accurate comparison to use the behavior of capuchin monkeys in a laboratory setting to ascribe judgments on human society, the prostitution incident does raise important questions. Spanning across time and cultures, prostitution has been a part of almost every society in human history. If it truly is a natural facet of human existence, one must question the wisdom of criminalizing the behavior in states like Indiana and around the country.” — Excerpt from essay by Matthew Quintos
Citations:
Dubner, Stephen, and Steven Levitt. “Monkey Business.” The New York Times, 5 June 2005, www.nytimes.com/2005/06/05/magazine/monkey-business.html.
“From observing patterns of polygyny and monogamy in primates, the science behind humans changing their sexual pattern may be explained…. In primates, polygyny is common when females are spread out and male territories overlap multiple female territories. If there is higher or equal ratio of females to males, there is a higher chance of polygyny (Gomes, 2018)…. [In humans] the benefits of monogamy must have also outweighed the benefits of polygyny. This means that security, cooperation, parental certainty, and a two-parent support system for offspring must have proven a more effective way to pass on genes than just the fittest of males getting to mate. So, all of these conditions must have been met through human history, revealing a lot about the human condition. Using evidence from primates, we can understand much of the basis of the shift in human sexuality…..Shifts in human sexuality are very, very complicated. Using comparisons between primates and humans may unlock important clues as to why humans evolved from polygyny to monogamy, including changes in population makeup, the importance of males taking care of offspring, et cetera. However, this approach is not all-encompassing, and there must also be human culture taken into account.” — Excerpt from essay by Sally Canfield
Citations: Gomes, B V et al. “Female dispersion and sex ratios interact in the evolution of mating behavior: a computational model.” Scientific reports vol. 8,1 2467. 6 Feb. 2018, doi:10.1038/s41598–018–20790–7
