Gerald H Jacobs
Biographic Data
| ID | 625132 |
|---|---|
| NAME | Gerald H Jacobs |
| GIVEN NAMES | Gerald H |
| FAMILY NAME | Jacobs |
| SIGNATURE | JACOBS G H |
| AFFILIATIONS | University of California, Santa Barbara |
| VERIFIED | No |
| TOTAL WORKS | 15 |
| TOTAL CITATIONS | 17 |
| AUTHOR COUNT | 15 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1973 |
| LATEST PUBLICATION YEAR | 2012 |
| H-INDEX | 2 |
Comparative Vision
Almost all animals have eyes and make extensive use of visual information to support the critical choices they must make to survive and prosper. The chapter starts with a discussion of the informational possibilities offered by the photic environment and then provides a comparative examination of the basic biological mechanisms underlying animal vision. The latter includes a consideration of eye design and photosensitivity with an examination of …
Characterization of opsin gene alleles affecting color vision in a wild population of titi monkeys ( Callicebus brunneus )
The color vision of most platyrrhine primates is determined by alleles at the polymorphic X‐linked locus coding for the opsin responsible for the middle‐ to long‐wavelength (M/L) cone photopigment. Females who are heterozygous at the locus have trichromatic vision, whereas homozygous females and all males are dichromatic. This study characterized the opsin alleles in a wild population of the socially monogamous platyrrhine monkey Callicebus brunn…
Color Vision Variation and Foraging Behavior in Wild Neotropical Titi Monkeys (Callicebus brunneus)
Mutational changes in S‐cone opsin genes common to both nocturnal and cathemeral Aotus monkeys
Aotus is a platyrrhine primate that has been classically considered to be nocturnal. Earlier research revealed that this animal lacks a color vision capacity because, unlike all other platyrrhine monkeys, Aotus has a defect in the opsin gene that is required to produce short‐wavelength sensitive (S) cone photopigment. Consequently, Aotus retains only a single type of cone photopigment. Other mammals have since been found to show similar losses an…
New World Monkeys and Color
Diurnality and cone photopigment polymorphism in strepsirrhines
Trichromatic color vision is routine among catarrhine primates, but occurs only as a variant form of color vision in some individuals in most platyrrhine genera. This arises from a fundamental difference in the organization of X‐chromosome cone opsin genes in these two lineages: catarrhines have two opsin genes specifying middle‐ and long‐wavelength‐sensitive cone pigments, while platyrrhines have only a single gene. Some female platyrrhine monke…
Progress toward understanding the evolution of primate color vision
Spectral sensitivity and photopigments of a nocturnal prosimian, the bushbaby ( Otolemur crassicaudatus )
Spectral sensitivity and photopigments of a nocturnal prosimian, the bushbaby (Otolemur crassicaudatus)
Earlier studies yielded conflicting conclusions on the types of photoreceptors and photopigments found in the eyes of nocturnal prosimians. In this investigation a noninvasive electrophysiological procedure, electroretinogram flicker photometry, was employed to measure scotopic and photopic spectral sensitivity in the thick-tailed bushbaby (Otolemur crassicaudatus). The scotopic spectral sensitivity function of the bushbaby has a peak of about 50…
Variations in primate color vision
Among mammals, only the primates have acquired the biological machinery needed for highly acute color vision. That distinction led Gordon Walls, perhaps the foremost authority on comparative vision of this century, to suggest long ago that “the color vision of the higher primates is assuredly a law unto itself, genetically and historically speaking.” 1 Primate color vision is indeed unique. One manifestation of this uniqueness is that color visio…
Photopigments underlying color vision in ringtail lemurs ( Lemur catta ) and brown lemurs ( Eulemur fulvus )
A recent examination of color vision in the ringtail lemur produced evidence that these prosimians could make color discriminations consistent with a diagnosis of trichromatic color vision. However, it was unclear if this behavior reflected the presence of three classes of cone or whether lemurs might be able to utilize signals from rods in conjunction with those from only two classes of cone. To resolve that issue, spectral sensitivity functions…
Spectral sensitivity of vervet monkeys ( Cercopithecus aethiops sabaeus ) and the issue of catarrhine trichromacy
Several genera of platyrrhine monkeys show significant polymorphism of color vision. By contrast, catarrhine monkeys have usually been assumed to have uniform trichromatic color vision. However, the evidential basis for this assumption is quite limited. To study this issue further, spectral sensitivity functions were obtained from vervet monkeys (Cercopithecus aethiops sabaeus) using the technique of electroretinographic flicker photometry. Resul…
Color vision variations in Old and New World primates
It has long been recognized that there are significant individual variations in color vision among humans. Recently, even more widespread individual variation in color vision has been found to occur in members of several genera of New World monkeys. This article addresses the question of whether a representative genus of Old World monkeys, Macaca , expresses individual variations in color vision. The principal approach was to compare behavioral m…
ERG Indices of Color Vision Variations in Monkeys
Visual sensitivity in the squirrel monkey
Several indices of visual sensitivity have been obtained from behavioral experiments conducted on the squirrel monkey ( Saimiri sciureus ). In this species, the photopic spectral sensitivity functions determined by increment‐threshold and flicker discrimination procedures are substantially different; the involvement of two different neural processes in the two tasks is suggested. When tested similarly, the thresholds for rod and cone‐based vision…
Variations in primate color vision
Among mammals, only the primates have acquired the biological machinery needed for highly acute color vision. That distinction led Gordon Walls, perhaps the foremost authority on comparative vision of this century, to suggest long ago that “the color vision of the higher primates is assuredly a law unto itself, genetically and historically speaking.” 1 Primate color vision is indeed unique. One manifestation of this uniqueness is that color visio…
New World Monkeys and Color
Color Vision Variation and Foraging Behavior in Wild Neotropical Titi Monkeys (Callicebus brunneus)
Visual sensitivity in the squirrel monkey
Several indices of visual sensitivity have been obtained from behavioral experiments conducted on the squirrel monkey ( Saimiri sciureus ). In this species, the photopic spectral sensitivity functions determined by increment‐threshold and flicker discrimination procedures are substantially different; the involvement of two different neural processes in the two tasks is suggested. When tested similarly, the thresholds for rod and cone‐based vision…
ERG Indices of Color Vision Variations in Monkeys
Color vision variations in Old and New World primates
It has long been recognized that there are significant individual variations in color vision among humans. Recently, even more widespread individual variation in color vision has been found to occur in members of several genera of New World monkeys. This article addresses the question of whether a representative genus of Old World monkeys, Macaca , expresses individual variations in color vision. The principal approach was to compare behavioral m…
Spectral sensitivity of vervet monkeys ( Cercopithecus aethiops sabaeus ) and the issue of catarrhine trichromacy
Several genera of platyrrhine monkeys show significant polymorphism of color vision. By contrast, catarrhine monkeys have usually been assumed to have uniform trichromatic color vision. However, the evidential basis for this assumption is quite limited. To study this issue further, spectral sensitivity functions were obtained from vervet monkeys (Cercopithecus aethiops sabaeus) using the technique of electroretinographic flicker photometry. Resul…
Photopigments underlying color vision in ringtail lemurs ( Lemur catta ) and brown lemurs ( Eulemur fulvus )
A recent examination of color vision in the ringtail lemur produced evidence that these prosimians could make color discriminations consistent with a diagnosis of trichromatic color vision. However, it was unclear if this behavior reflected the presence of three classes of cone or whether lemurs might be able to utilize signals from rods in conjunction with those from only two classes of cone. To resolve that issue, spectral sensitivity functions…
Variations in primate color vision
Among mammals, only the primates have acquired the biological machinery needed for highly acute color vision. That distinction led Gordon Walls, perhaps the foremost authority on comparative vision of this century, to suggest long ago that “the color vision of the higher primates is assuredly a law unto itself, genetically and historically speaking.” 1 Primate color vision is indeed unique. One manifestation of this uniqueness is that color visio…
Spectral sensitivity and photopigments of a nocturnal prosimian, the bushbaby ( Otolemur crassicaudatus )
Spectral sensitivity and photopigments of a nocturnal prosimian, the bushbaby (Otolemur crassicaudatus)
Earlier studies yielded conflicting conclusions on the types of photoreceptors and photopigments found in the eyes of nocturnal prosimians. In this investigation a noninvasive electrophysiological procedure, electroretinogram flicker photometry, was employed to measure scotopic and photopic spectral sensitivity in the thick-tailed bushbaby (Otolemur crassicaudatus). The scotopic spectral sensitivity function of the bushbaby has a peak of about 50…
Diurnality and cone photopigment polymorphism in strepsirrhines
Trichromatic color vision is routine among catarrhine primates, but occurs only as a variant form of color vision in some individuals in most platyrrhine genera. This arises from a fundamental difference in the organization of X‐chromosome cone opsin genes in these two lineages: catarrhines have two opsin genes specifying middle‐ and long‐wavelength‐sensitive cone pigments, while platyrrhines have only a single gene. Some female platyrrhine monke…
Progress toward understanding the evolution of primate color vision
Mutational changes in S‐cone opsin genes common to both nocturnal and cathemeral Aotus monkeys
Aotus is a platyrrhine primate that has been classically considered to be nocturnal. Earlier research revealed that this animal lacks a color vision capacity because, unlike all other platyrrhine monkeys, Aotus has a defect in the opsin gene that is required to produce short‐wavelength sensitive (S) cone photopigment. Consequently, Aotus retains only a single type of cone photopigment. Other mammals have since been found to show similar losses an…
New World Monkeys and Color
Characterization of opsin gene alleles affecting color vision in a wild population of titi monkeys ( Callicebus brunneus )
The color vision of most platyrrhine primates is determined by alleles at the polymorphic X‐linked locus coding for the opsin responsible for the middle‐ to long‐wavelength (M/L) cone photopigment. Females who are heterozygous at the locus have trichromatic vision, whereas homozygous females and all males are dichromatic. This study characterized the opsin alleles in a wild population of the socially monogamous platyrrhine monkey Callicebus brunn…
Color Vision Variation and Foraging Behavior in Wild Neotropical Titi Monkeys (Callicebus brunneus)
Comparative Vision
Almost all animals have eyes and make extensive use of visual information to support the critical choices they must make to survive and prosper. The chapter starts with a discussion of the informational possibilities offered by the photic environment and then provides a comparative examination of the basic biological mechanisms underlying animal vision. The latter includes a consideration of eye design and photosensitivity with an examination of …
Biology (12 works) · Color vision (9 works) · Trichromacy (8 works) · Zoology (8 works) · Primate (7 works) · Primate Behavior and Ecology (7 works) · Retinal Development and Disorders (7 works) · Visual perception and processing mechanisms (7 works) · Computer Science (6 works) · Olfactory and Sensory Function Studies (6 works)