Our Senses: How Mammals See the World In Many Colors

OUR SENSES: HOW MAMMALS SEE THE WORLD IN MANY COLORS 

Published January 25, 2018

[The Museum’s logo appears. Behind it and out of focus, an animated eye blinks.]

[MUSIC PLAYS]

[Zoom in to an illustration of a cone cell—an elongated form with a ridged cone shape on the end.]

ROB DESALLE (Curator, Division of Invertebrate Zoology): A cone cell is a cell in the retina of your eye.

[Zoom out to a diagram of a human eye. A line animates to the back of the eyeball, and bounces back at an angle, followed by the appearance of text—“RETINA.”]

[Zoom in to a row of cone cells.]

DESALLE: And the field of cone cells can translate all kinds of different colors that we see in the environment. 

[Cone cells shrink in frame, and are silhouetted, as if they are a movie theater audience. On the “screen” before them, footage appears of multi-colored flowers.]

[Cut to a single cone cell. The camera zooms in to one of the cone cell’s ridges. There, we see a twisting, coiling form, representing a protein.] 

DESALLE: The cone cell has an amazing kind of a protein embedded in its membrane called an opsin. 

[A dotted line animates out from the protein, and the text “OPSIN” appears.]

[Three opsin protein forms appear over the colors red, green, and blue.]

DESALLE: There’s a red opsin protein, and a green opsin protein, and a blue opsin protein. 

[Cut to the opsin protein in the cone cell. The camera zooms into the protein, and the illustration of a molecule appears in the middle of the opsin. A dotted line animates out, and the text “RETINAL” appears.]

DESALLE: And this protein has a little molecule in it called retinal that’s just kind of nestled inside of the protein. 

[Three opsin proteins—red, green, and blue—grow in size, and then shrink, moving to the bottom third of the screen Above each plays a piece of footage corresponding in color with the opsins—a red rose blooms above the red opsin, a green frog sits above the green opsin, and blue ocean waves above the blue opsin.]

DESALLE: The opsin proteins, they’re all programmed, so to speak, to toss out the retinal when they’re hit by a specific wavelength of light. 

[The opsin proteins have cartoon arms, which reach into their forms, take out the retinal molecules and toss them away. This action is repeated several times]

[A single opsin protein with cartoon arms makes signals with semaphore flags.]

DESALLE: When they toss out this retinal, they send a signal to the cell…

[A nerve cell also holds semaphore flags, and signals with them.]

DESALLE: …that then sends a signal to your nervous system… 

[The camera quickly tracks up and down, following the course of a zigzagging line.]

DESALLE: …that goes to your brain. 

[An illustrated brain appears. Zoom into the brain, which flashes red.]

DESALLE: And that’s how you interpret the colors.

[An illustrated bat swings from a branch on the left of the screen, while on the right an illustrated beluga whale bobs up and down.] 

DESALLE: Some mammals have no color vision whatsoever. They see things in black and white.

[Curator Rob DeSalle speaks in his office. On-screen text gives his name and title as “Curator, Division of Invertebrate Zoology.”] 

DESALLE: Color vision, more than likely, evolved in primates about 35 million years ago. 

[Three illustrated monkeys in red, green, and blue, sit on an abstracted shape, in front of an archival photo of a rainforest. The text “SQUIRREL MONKEY (Samiri sciureus)” appears, and dotted lines animate out from the text to the three monkeys.]

DESALLE: Some monkey species have incredibly interesting color vision. 

[A vintage cartoon plays, surrounded by a cutout of an elaborate movie theater curtain. The cartoon is shown in a limited color range, and depicts an elderly woman looking at a monkey in a zoo cage. A sign in front of the monkey reads, “Do not feed the monkeys.” A silhouette of a monkey from behind is on the right side of the screen, as if that monkey is seated in the theater, watching the cartoon.]

DESALLE: Some monkeys in the population see two colors…

[The monkey on the right disappears, and a different monkey appears on the left. The cartoon continues to play, but now has a greater variety of colors.]

DESALLE: …and other monkeys see three. 

[The monkey on the right reappears. Both monkeys watch the cartoon, which is now a split screen. On the left, the cartoon appears in full color. On the right, the number of colors is restricted.] 

DESALLE: So, you have this population of monkeys where one part of it’s seeing a completely different colored world than the other part of it.

[Cut to a close up of two monkey faces in front of a forest scene. The scene behind the monkey on the right appears in full color, and on the left, with a more restricted color range.]

[MUSIC PLAYS]

[Card appears saying: “American Museum of Natural History, Our Senses: An Immersive Experience, Open Through January 2019. Our Senses is generously supported by Dana and Virginia Randt.”]

[Credits roll.]