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Ranging in size from the 30 g (1.1 oz) Madame Berthe's mouse lemur, the world's smallest primate, [48] to the extinct 160–200 kg (350–440 lb) Archaeoindris fontoynonti, [49] lemurs evolved diverse forms of locomotion, varying levels of social complexity, and unique adaptations to the local climate.
Lemurs share resemblance with other primates, but evolved independently from monkeys and apes. Due to Madagascar's highly seasonal climate, lemur evolution has produced a level of species diversity rivaling that of any other primate group. Living lemurs range in weight from the 30-gram (1.1 oz) mouse lemur to the 9-kilogram (20 lb) indri.
The aye-aye, mouse lemurs, woolly lemurs, and sportive lemurs are nocturnal, while ring-tailed lemurs and most of their kin, sifakas, and indri are diurnal. [80] Yet some or all of the brown lemurs ( Eulemur ) are cathemeral , which means that they may be active during the day or night, depending on factors such as temperature and predation ...
The human eye, showing the iris and pupil. In 1802, philosopher William Paley called it a miracle of "design."In 1859, Charles Darwin himself wrote in his Origin of Species, that the evolution of the eye by natural selection seemed at first glance "absurd in the highest possible degree". [3]
Unlike most other lemurs, all but one species of lemurid (the ring-tailed lemur) lack a tapetum lucidum, [7] a reflective layer in the eye that improves night vision. Historically among mammals, activity cycles are either strictly diurnal or nocturnal, however, these can widely vary across species.
The eventual ancestor of cattle, aurochs (Bos primigenus), evolves in India. 1.7 Ma Australopithecines go extinct. 1.2 Ma Evolution of Homo antecessor. The last members of Paranthropus die out. 1 Ma First coyotes. 810 ka First wolves: 600 ka Evolution of Homo heidelbergensis. 400 ka First polar bears. 350 ka Evolution of Neanderthals. 300 ka
An early branch of this clade gave rise to lemuriform primates, which includes lemurs and their kin. David Begun has theorised that early primates flourished in Eurasia and that a lineage leading to the African apes and humans, including Dryopithecus, migrated south from Europe or Western Asia into Africa. [4]
The evolution of color vision in primates is highly unusual compared to most eutherian mammals. A remote vertebrate ancestor of primates possessed tetrachromacy , [ 1 ] but nocturnal , warm-blooded , mammalian ancestors lost two of four cones in the retina at the time of dinosaurs .