1. Nocturnal Vision Samiha Khan

2. Nocturnal Vision  Most nocturnal animals have modified their eyes to enhance their ability to capture adequate light or photons: Modified eye structure: Modified eye structure: larger pupils and shorter focal length heightens sensitivity larger pupils and shorter focal length heightens sensitivity Nocturnal Animals have modified retinas: Nocturnal Animals have modified retinas: Have mostly rods to enhance light sensitivityHave mostly rods to enhance light sensitivity Do not have as many cones, which are sensitive to color. Therefore, many nocturnal animals are monochromatic.Do not have as many cones, which are sensitive to color. Therefore, many nocturnal animals are monochromatic. Monochromatic animals tend to have a nonfunctional S- opsin gene. Monochromatic animals tend to have a nonfunctional S- opsin gene.

3. Color Vision in Nocturnal Animals  There are nocturnal animals that have attained color vision. Dichromatic animals have a combination of two functional opsin genes.Dichromatic animals have a combination of two functional opsin genes. Functional S-opsin and M-opsin: Sensitivity to violet and green light Functional S-opsin and M-opsin: Sensitivity to violet and green light Functional S-opsin and L-opsin: Sensitivity to violet and yellow-green light Functional S-opsin and L-opsin: Sensitivity to violet and yellow-green light Trichromatic animals have a combination of three opsin genes Trichromatic animals have a combination of three opsin genes Females have S-opsin as well as L-opsin and M- opsin genes visualize violet, green and yellow light Females have S-opsin as well as L-opsin and M- opsin genes visualize violet, green and yellow light Due to a duplication of geneDue to a duplication of gene Is X-linkedIs X-linked

4. Color Vision in Nocturnal Animals Color vision has duplicated independently in nocturnal animals. Color vision has duplicated independently in nocturnal animals. Natural selection selected for color vision in nocturnal animals has caused convergent evolution Natural selection selected for color vision in nocturnal animals has caused convergent evolution It is believed that color vision was selected for in these animals and has improved their foraging skills It is believed that color vision was selected for in these animals and has improved their foraging skills