What makes us human?
Answers
Answer:
Explanation:
There are multiple theories about what makes us human—several that are related or interconnected. The topic of human existence has been pondered for thousands of years. Ancient Greek philosophers Socrates, Plato, and Aristotle all theorized about the nature of human existence as have countless philosophers since. With the discovery of fossils and scientific evidence, scientists have developed theories as well. While there may be no single conclusion, there is no doubt that humans are, indeed, unique. In fact, the very act of contemplating what makes us human is unique among animal species.
Most species that have existed on planet Earth are extinct, including a number of early human species. Evolutionary biology and scientific evidence tell us that all humans evolved from apelike ancestors more than 6 million years ago in Africa. Information obtained from early-human fossils and archaeological remains suggests that there were 15 to 20 different species of early humans several million years ago. These species, called hominins, migrated into Asia around 2 million years ago, then into Europe and the rest of the world much later. Although different branches of humans died out, the branch leading to the modern human, Homo sapiens, continued to evolve.
Humans have much in common with other mammals on Earth in terms of physiology but are most like two other living primate species in terms of genetics and morphology: the chimpanzee and bonobo, with whom we spent the most time on the phylogenetic tree. However, as much like the chimpanzee and bonobo as we are, the differences are vast.
Apart from our obvious intellectual capabilities that distinguish us as a species, humans have several unique physical, social, biological, and emotional traits. Although we can't know precisely what is in the minds of other animals, scientists can make inferences through studies of animal behavior that inform our understanding.
Thomas Suddendorf, professor of psychology at the University of Queensland, Australia, and author of "The Gap: The Science of What Separates Us From Other Animals," says that "by establishing the presence and absence of mental traits in various animals, we can create a better understanding of the evolution of mind. The distribution of a trait across related species can shed light on when and on what branch or branches of the family tree the trait is most likely to have evolved."
As close as humans are to other primates, theories from different fields of study, including biology, psychology, and paleoanthropology, postulate that certain traits are uniquely human. It is particularly challenging to name all of the distinctly human traits or reach an absolute definition of "what makes us human" for a species as complex as ours.
The Larynx (Voice Box)
Larynx anatomical vector illustration diagram, educational medical scheme.
normaals / Getty Images
Dr. Philip Lieberman of Brown University explained on NPR's "The Human Edge" that after humans diverged from an early-ape ancestor more than 100,000 years ago, the shape of the mouth and vocal tract changed, with the tongue and larynx, or voice box, moving further down the tract.
The tongue became more flexible and independent and was able to be controlled more precisely. The tongue is attached to the hyoid bone, which is not attached to any other bones in the body. Meanwhile, the human neck grew longer to accommodate the tongue and larynx, and the human mouth grew smaller.