Evolution of colour vision
The evolution of color vision causes light to be seen according to its wavelength. This has obvious advantages, especially it helps animals find food.
The color vision of many herbivores allows them to see fruit or (immature) leaves which are good to eat. In hummingbirds, particular flowers are often recognized by color. Predators also use color vision to help them find their prey.
All this applies mainly to animals in the daytime. On the other hand, nocturnal mammals have much less-developed color vision. For them, space on the retina is better used with more rods since rods collect light better. Color differences are much less visible in the dark.
Arthropods
changeApart from vertebrates,[1] the only land animals to have color vision are arthropods.[2] So insects and spiders have quite good color vision. Aquatic arthropods such as crustacea also have color vision. As with vertebrates, the details differ, but the molecules which do the work – the opsins – are very similar.
Vertebrates
changeFour photopigment opsins exist in teleost fish, reptiles and birds.[3] This suggests that the common ancestor of tetrapods and amniotes (~360 million years ago) had full color vision:
- "rods and four spectral classes of cone each [have] one of the five visual pigment families. The complement of four spectrally distinct cone classes gives these species the potential for tetrachromatic color vision".[4][5]
Mammals
changeIn contrast, mammals lost much of their color vision capability during the long period in the Mesozoic when they lived as nocturnal animals.[4][6]
- "...two cone opsin gene families appear in contemporary eutherian mammals and, with the exception of some primates, none of these animals derive more than a single photopigment type from each of their two gene families".[5]
Many primates do live as daytime animals, and one group – the Old World monkeys – has trichromatic vision.[7] The anthropoid apes and humans are descended from this group of monkeys,[8] and also have good color vision. So it comes about that most monkeys and humans have good color vision, but most other eutherian mammals do not: they have only two opsins, and so they are bichromatic.[9]
This has many consequences. For example, most deer cannot see red or orange. Thus they do not see the orange color of tigers. But monkeys do, because primates have one more opsin than other mammals. A film by David Attenborough illustrates this well.[10]
UV light
changeUltraviolet light plays a part in color perception in many animals, especially insects.
Color vision, with UV discrimination, is present in many arthropods—the only terrestrial animals besides the vertebrates to have this trait.[2]
Birds, turtles, lizards, many fish and some rodents have UV receptors in their retinas.[11] These animals can see the UV patterns found on flowers and other wildlife that are invisible to the human eye.[12][13]
References
change- ↑ Lamb T.D; Collin S.P. & Pugh E.N. Jr. 2007. Evolution of the vertebrate eye: opsins, photoreceptors, retina and eye cup. Nature Reviews Neuroscience. 8 (12): 960–976. [1]
- ↑ 2.0 2.1 Koyanagi M. et al 2008. Molecular evolution of arthropod color vision deduced from multiple opsin genes of jumping spiders. Journal of Molecular Evolution 66 (2): 130–137. [2]
- ↑ Yokoyama S. & Radlwimmer B.F. 2001. The molecular genetics and evolution of red and green color vision in vertebrates. Genetics Society of America. 158: 1697-1710.
- ↑ 4.0 4.1 Bowmaker J.K. 1998. Evolution of colour [sic] vision in vertebrates. Eye 12 (3b): 541–547. [3] (Prose slightly simplified)
- ↑ 5.0 5.1 Jacobs G.H. 2009. The evolution of colour [sic] vision in mammals. Phil Trans Roy Soc B. 364 (1531) 2957-2967. [4]
- ↑ Kemp T.S. 2005. The origin and evolution of mammals. Oxford University Press.
- ↑ There was gene duplication of one of their opsin genes.
- ↑ The group is called the catarrhines.
- ↑ Evolution of colour [sic] vision in vertebrates. Eye 12 (3b): 541–547.
- ↑ BBC: Attenborough's life in colour [sic]: 1.2 Hiding in colour [sic]. [5]
- ↑ Jacobs G.H; Neitz J. & Deegan J.F. (1991). "Retinal receptors in rodents maximally sensitive to ultraviolet light". Nature. 353 (6345): 655–6. Bibcode:1991Natur.353..655J. doi:10.1038/353655a0. PMID 1922382. S2CID 4283145.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ↑ Varela F.J.; et al. (1993). Vision, brain, and behavior in birds. Cambridge, Mass: MIT Press. pp. 77–94. ISBN 0-262-24036-X.
- ↑ Cuthill I.C.; et al. (2000). "Ultraviolet vision in birds". Advances in the study of behavior. Vol. 29. pp. 159–214.