Search results
Results from the WOW.Com Content Network
Sleep can follow a physiological or behavioral definition. In the physiological sense, sleep is a state characterized by reversible unconsciousness, special brainwave patterns, sporadic eye movement, loss of muscle tone (possibly with some exceptions; see below regarding the sleep of birds and of aquatic mammals), and a compensatory increase following deprivation of the state, this last known ...
Human interactions with chimpanzees may be especially dangerous if the chimpanzees perceive humans as potential rivals. [184] At least six cases of chimpanzees snatching and eating human babies are documented. [185] A chimpanzee's strength and sharp teeth mean that attacks, even on adult humans, can cause severe injuries.
English: Comparison of size of adult chimpanzee (Pan troglodytes) and adult human. This image assumes a height of 1.75 m for the human and 1.2 m for the chimpanzee. This image assumes a height of 1.75 m for the human and 1.2 m for the chimpanzee.
A chimpanzee's testicles are unusually large for its body size, with a combined weight of about 4 oz (110 g) compared to a gorilla's 1 oz (28 g) or a human's 1.5 ounces (43 g). This relatively great size is generally attributed to sperm competition due to the polygynandrous nature of chimpanzee mating behaviour .
The endocranial volume (the volume within the skull) is three times greater in humans than in the greatest nonhuman primate, reflecting a larger brain size. [70] The mean endocranial volume is 1,201 cubic centimeters in humans, 469 cm 3 in gorillas , 400 cm 3 in chimpanzees and 397 cm 3 in orangutans . [ 70 ]
Eventually they became so big that it was no longer possible for them to get both safe and proper sleep on bare branches alone, so they started building sleeping platforms in the trees. This appeared to have happened when their weight passed 30 kilos, as only apes above 32 kilos build nests. [16] [17] Which in turn led to shorter and deeper ...
A typical precocial mammal has a gestation period almost four times longer than a typical altricial mammal of the same body size. [34] Precocial mammal species generally have greater adult body weights than altricial mammals as precocial mammals have markedly longer gestation periods than altricial mammals. [35]
By comparing human and chimpanzee genes to the genes of other mammals, it has been found that genes coding for transcription factors, such as forkhead-box P2 , have often evolved faster in the human relative to chimpanzee; relatively small changes in these genes may account for the morphological differences between humans and chimpanzees. A set ...