It's important to clarify that scientists do not say that humans originated from apes; rather, they assert that humans and apes share a common ancestry. The theory of evolution, which is supported by a vast body of evidence from multiple scientific disciplines, including paleontology, genetics, and comparative anatomy, proposes that all living organisms, including humans and apes, have evolved from a common ancestor that lived millions of years ago.
The scientific consensus is that humans and apes, including chimpanzees, gorillas, and orangutans, belong to the same family of primates known as Hominidae. Approximately 6 to 8 million years ago, a common ancestor of both humans and apes existed, and from that point on, different evolutionary paths were followed, leading to the emergence of modern humans and the various species of apes we see today.
The evidence for this common ancestry comes from various sources, such as:
Fossil record: Paleontologists have discovered numerous ancient hominid fossils that provide a detailed record of our evolutionary history. These fossils show transitional forms that demonstrate the gradual changes in anatomy and behavior over time.
Genetic evidence: Comparative studies of the DNA of humans and other primates have revealed striking similarities and shared genetic sequences, providing strong evidence for a common ancestry.
Comparative anatomy: The anatomical similarities between humans and other apes, such as bone structures, organ systems, and even behavioral traits, suggest a shared evolutionary heritage.
Biogeography: The distribution of species around the world also provides evidence of common ancestry. For example, the geographical proximity of great apes to humans in Africa fits well with the idea of a shared ancestral population in that region.
In summary, scientists say that humans and apes share a common ancestry because the evidence from multiple fields of study overwhelmingly supports the theory of evolution, which posits that all life on Earth is connected through a complex process of common descent and adaptation over millions of years.