![]() In particular, orangutans did not spit water into an empty tube upon encountering a peanut that was out of reach (in front of the tube). Additionally, control conditions demonstrated that spitting inside the tube was not a general response that subjects displayed upon encountering an out-of-reach reward. Releasing water from their mouths into the tube raised the water level and brought the peanut within reach. Recently, Mendes, Hanus and Call reported five orangutans repeatedly spitting water into a tube to retrieve a peanut that was floating at the bottom of the tube in a small amount of water. The vast majority of tools used by animals consists of solid materials or are constructed from them. Reports of such behavior originate from natural observations – as well as from experimental studies –. Within the oldest group (8 years), 58 percent of the children solved the problem, whereas in the youngest group (4 years), only 8 percent were able to find the solution.Ī variety of sophisticated tool-using behavior is known to occur in several vertebrates, including birds and mammals –. Finally, we tested how human children of different age classes perform in an analogous experimental setting. We found suggestive evidence for the view that functional fixedness might have impaired the chimpanzees' strategies in the first experiment. Another experiment was conducted to investigate the reason for the differences in performance between the unsuccessful (Experiment 1) and the successful (Experiment 2) chimpanzee populations. Additional controls revealed that successful subjects added water only if it was necessary to obtain the nut. Twenty percent of the chimpanzees but none of the orangutans were successful. In order to better understand the cognitive demands of the task, we further tested other populations of chimpanzees and orangutans with the variation of the peanut initially floating or not. Here, we tested chimpanzees and gorillas for the first time with the same “floating peanut task.” None of the subjects solved the task. described the use of a liquid tool (water) in captive orangutans. This is especially true for the mountain gorillas.Recently, Mendes et al. Gorillas spend more time on the ground than other apes, therefore their feet are more suited to walking. ![]() For instance, the gorillas' hands and feet resemble the human ones more than those of other apes. In mitochondrial DNA, which changes considerably faster, geneticists found a difference in 8.8% between humans and chimpanzees, 10.3% between humans and gorillas, 10.6% between chimpanzees and gorillas and 16-17% difference between the other species and the orang-utan.Īlthough chimpanzees and bonobos are the closest relatives of humans, gorillas resemble us more in some respects. In contrast, analyzed parts of the genetic material of African apes and humans differ from the respective genetic material of the orang-utan by about 3.1%. Certain genes that were analyzed differ by only 1.2% between humans and chimpanzees, by 1.6% between humans and gorillas and by 1.8% between gorillas and chimpanzees. Differences are especially small in the nuclear DNA. ![]() The genetic material of apes is identical to that of humans to a very large degree. The orang-utans are only remotely related to the other species. According to their research, the chimpanzees are the closest relatives of humans the next in line are the gorillas. More recently, most experts have concluded that this view is out of date. This division was based on certain anatomical specialisations, mainly the highly developed human brain and the unique locomotion. In former times, the human species used to be put into its own taxonomic family (Hominidae), while the great apes were put in a different family, Pongidae.
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