There's a biological analogue here

• A frog species evolves to be poisonous, making them less palatable to predators.

• A different Delicious frog species evolves to visually mimic the Poisonous frog.

• This creates an evolutionary pressure for the Poisonous frog to change its appearance to less resemble the Delicious frog. The pressure is stronger the more the Delicious frog outnumbers the Poison frog.

• The cycle repeats.