Humans are undoubtedly one of the most fascinating species on Earth. We are not only complex beings with intricate emotions, thoughts, and behaviors, but we also share many fundamental characteristics with other animals. In fact, humans can be classified as animals, vertebrates, and chordates, making us a part of all these categories.
Firstly, humans are animals. This may come as a surprise to some, as we often associate the term “animal” with other non-human creatures. However, the biological definition of an animal encompasses a wide range of organisms, including humans. Animals are multicellular eukaryotic organisms that lack cell walls, obtain energy through ingestion, and have the ability to move voluntarily. Humans meet all these criteria, as we are composed of multiple cells, lack cell walls like plant cells, consume food for energy, and possess the power of voluntary movement.
Moving on, humans are also vertebrates. Vertebrates are a subphylum of animals that possess a backbone or spinal column, which provides support and protection to the delicate nervous system. This distinguishing feature sets vertebrates apart from invertebrates, which lack a backbone. Our backbone, also known as the vertebral column, is made up of a series of bones called vertebrae. These vertebrae house and safeguard our spinal cord, a vital component of our central nervous system responsible for transmitting information between the brain and the rest of the body. Therefore, as humans possess a backbone and spinal cord, we fall under the category of vertebrates.
Furthermore, humans are classified as chordates. Chordates represent a phylum within the animal kingdom and are characterized by possessing a notochord, a hollow dorsal nerve cord, gill slits, and a post-anal tail at some point during their life cycle. Although these features may not be readily apparent in adult humans, they are present during early embryonic development. The notochord, a flexible rod-like structure, forms along the back of the embryo, providing support and acting as a precursor to the backbone. The dorsal nerve cord, derived from the notochord, eventually develops into the spinal cord. Additionally, gill slits and a post-anal tail are present in human embryos for a brief period, signifying our chordate heritage.
To summarize, humans can be classified as animals, vertebrates, and chordates. We share fundamental characteristics with other animals, such as being multicellular, lacking cell walls, and exhibiting voluntary movement. As vertebrates, we possess a backbone that safeguards our spinal cord, distinguishing us from invertebrates. Lastly, humans are chordates due to the presence of a notochord, dorsal nerve cord, gill slits, and post-anal tail during embryonic development. These classifications highlight our biological relationship with other organisms, emphasizing the interconnectedness and diversity of life on Earth.