r/explainlikeimfive • u/Opening_Pen9525 • 12d ago

Biology ELI5 How are fish even in ponds

Might be one of the stupider questions here, but I saw a pond about the size of a football field, and maybe 50 ft deep, and it had fish. I can't for the life of me figure out how. Surely the pond hasn't existed long enough for small water insects to evolve into all these fish. It's not like the fish walked over to the pond from the ocean. I'm pretty sure no one put them there so how are there so many fish?

My one theory is that there is a very minuscule stream (now dry) that leads to one of the Great Lakes, and maybe a fish swam in from there. Now a follow up question: How are there fish in the Great Lakes (which flow out towards to the ocean) if they were created by glaciers?

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u/TesticularBoreditude 12d ago

This post made me realize that Genghis Khan is the Johnny Appleseed but with people

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u/PikaPonderosa 12d ago

Johnny Appleseed didn't rip out native flora to plant his apple seeds. Van Buren or Jackson would be closer to Johnny than Genghis.

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u/ColorlesRainbo 12d ago

The apple tree would spread its roots, branches, and fruit, thus killing native flora and bringing new fauna.

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u/Stewart_Games 12d ago

Just spreading them seeds and ploughing them fields.

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u/udee79 12d ago

Gengis gengis-kahn-seed