The unity of life is the idea that all living organisms are related to each other through a common ancestor. This means that all living organisms share a common evolutionary history.

The theory of evolution by natural selection provides the most comprehensive explanation for the unity of life because it explains how different organisms can evolve from a common ancestor over time. This theory explains how organisms can adapt to their environment and how new species can be formed.

The fossil record, the comparative anatomy of different organisms, and the genetic similarities between different organisms all provide evidence that supports the theory of common descent. The fossil record shows that different organisms have evolved over time, and that these organisms share common ancestors. The comparative anatomy of different organisms shows that these organisms have similar structures, which suggests that they share a common ancestor. The genetic similarities between different organisms show that these organisms have similar genes, which also suggests that they share a common ancestor.

The unity of life is significant because it helps us to understand the diversity of life on Earth, the evolutionary history of life on Earth, and the relationship between different organisms. By understanding the unity of life, we can better understand the world around us.

The unity of life shows that humans are not unique, that humans are related to all other living organisms, and that humans have a responsibility to protect the environment. By understanding the unity of life, we can better understand our place in the world and our relationship to other organisms.