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Full Version: Monarch Butterflies and Milkweed
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Milkweed is poisonous. When damaged or bitten into, it sends extra poisonous sap to the area as a way of protecting itself.

Monarch caterpillars, though, feed on milkweed. However when they hatch, they’re not entirely immune to the milkweed’s poison and they could die from eating their food, especially as the milkweed would send extra poison to the section being eaten. To overcome this problem, the caterpillar cuts out a circular section of the leaf that has low concentrations of the poison, and take it aside to feed on while the plant is busy sending lots of poison to the wound. As the caterpillar feeds on the leaf section it had cut out, it builds its immunity to the poison. This enables it to eat the milkweed without any problems. In doing this, it also becomes poisonous itself to predators! So, the poison of the milkweed protects the monarch, and the monarch in return pollinates the milkweed!

This relationship defies evolution .. how many monarch caterpillars died trying to figure out how to become resistant to the milkweed’s poison?

Unknown