Long term stabilizing selection can explain "living fossils."
Amber fossils sometimes conserve ancient insect species that are very similar to their modern relatives. Voltinia dramba is the first butterfly to be described from a 20 million-year-old fossil. One of its several close relatives is found in Mexico today.
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How are humans contributing to negative selection? It's a part of evolution that can also drive some species to extinction; models of negative selection help us understand biodiversity.
