In what context is the term "living fossil" used?

The term "living fossil" is used to refer to species that show minimal morphological change over long periods of geological time. These species often exhibit characteristics that have remained relatively stable compared to their ancient relatives or related extinct species. Living fossils provide valuable insights into the evolutionary history of organisms, as they help scientists understand how certain traits have been preserved while others have evolved significantly in different lineages.

The concept highlights species that have survived from ancient times and have changed little, suggesting a stable ecological niche or a lack of significant evolutionary pressures. Examples of "living fossils" include the coelacanth fish and the ginkgo tree, both of which have retained a resemblance to their ancient ancestors.

In contrast, species that have undergone significant evolution would not fit this definition as they display marked changes over time. Newly discovered species are not inherently "living fossils," as they may not have ancient relatives or a history of minimal change. Extinct species cannot be classified as "living fossils" since the term specifically refers to extant species that have persisted through substantial epochs of time without substantial morphological changes.