What does "descent with modification" refer to?

"Descent with modification" is a key concept in evolutionary biology, describing the process by which species evolve over time through various changes in their genetic makeup. This phrase, popularized by Charles Darwin, emphasizes that species are not static; instead, they undergo gradual changes as they adapt to their environments or through other mechanisms, such as genetic drift or gene flow.

The idea embodies that while species share a common ancestry, they diverge and change as they experience different selective pressures and mutations. This results in variations among descendant species, reflecting how life adapts and evolves over generations.

In this context, the choice that states "species are capable of changing over time" aligns perfectly with the essence of evolution. It highlights the dynamic nature of species, reinforcing that change is a fundamental characteristic of life on Earth.