Individuals of the same species, poison dart frogs, can vary greatly as far as color patterns go. Color patterns seen in a population depend on where the frog lives. Researchers from the University of Montreal performed a study in Peru using decoy frogs. They placed 3,600 clay frogs painted three different colors in different spots.
"In the highlands of the Cainarachi Valley there, the frogs are splashed with a green undulating pattern, almost like an abstract snakeskin pattern. In the lowlands only 6 miles (10 kilometers) away, the same species of frog boasts yellow stripes instead."
Frogs that had been painted to look like locals were much less likely to be attacked by predators, because the predators know frogs marked like that are poisonous. Frogs of the same species with different color patterns were twice as likely to become prey. Because the local frogs are known to be poisonous they are not chosen as prey and and much more likely to reproduce, spreading their color pattern.
The fact that color patterns varied so much in populations so close together I found particularly interesting. Also, the rate at which the predators learned that the decoy frogs do not make a good meal was also very surprising, as most of the attacks on the decoys had happened within a day of them being placed.
This ties in nicely to what we learned in class about evolution and speciation. Like you said, because predators learned to stay away from frogs of certain colors, those frogs are able to reproduce and pass on their genes for color. However, I imagine predators would learn to stop eating frogs that are equally as poisonous but of a different color as well. I wonder what would happen if real frogs of different patterns were introduced, would they be able to reproduce and thrive in the new environment? There must be a reason why frogs of only one color pattern are found in one area.
ReplyDeletePosted by James Lin
First off I am stunned by "They placed 3,600 clay frogs painted three different colors in different spots". That must have taken alot of time and a million dollar grant to event just place the frogs. A serious time commitment! I am surprised that there would be so much color variation in closely located areas. Cool that predators pick outsiders. I wonder if they just have not learned that the new pattern could also be poisonous.
ReplyDeletePosted by Caroline Adams
I am a little confused, so are the green frogs more likely to be attacked if placed in the yellow frog habitat? Or do predators avoid all frogs with bright colors? This relates to what we had talked in class about how many species advertise being poisonous with bright colors. Are all these species poisonous? It is shocking they painted 3600 frogs! That is quite the effort on their part.
ReplyDeletePosted by Caitlin Descovich O'Hare