Question

Classify humans by filling in the missing lines. $$\begin{array}{cc}\text{Domain} && \text {Eukarya}\end{array}$$ $$\begin{array}{cc}\text{Kingdom} && \text {Animalia}\end{array}$$ $$\begin{array}{cc}\text{Phylum} && \text {a. __________}\end{array}$$ $$\begin{array}{cc}\text{b. __________ } && \text {Mammalia}\end{array}$$ $$\begin{array}{cc}\text{c. __________ } && \text {Primates}\end{array}$$ $$\begin{array}{cc}\text{Family} && \text {d.__________}\end{array}$$ $$\begin{array}{cc}\text{e. __________} && \text {Homo}\end{array}$$ $$\begin{array}{cc}\text{Species} && \text {f. ___________}\end{array}$$

Short answer

The missing lines are: a. Chordata, b. Vertebrata, c. Theria, d. Hominidae, and f. sapiens. The complete classification is: Domain: Eukarya, Kingdom: Animalia, Phylum: Chordata, Subphylum: Vertebrata, Class: Mammalia, Subclass: Theria, Order: Primates, Family: Hominidae, Genus: Homo, and Species: sapiens.

Step-by-step solution

Identify the Phylum

Humans belong to the phylum Chordata. This phylum includes animals with a notochord, or a flexible rod-shaped structure that extends through the length of the body. Chordates also have a dorsal nerve cord and pharyngeal slits. So, replace 'a. __________' with 'Chordata'.

Identify the missing classification between Phylum and Class

In the taxonomic hierarchy, the classification between the Phylum and Class is the Subphylum. Humans belong to the subphylum Vertebrata. Vertebrates have a backbone or spinal column that houses the spinal cord. Replace 'b. __________' with 'Vertebrata'.

Identify the missing classification between Class and Order

Between Class (Mammalia) and Order (Primates), the missing classification is the subclass. Humans belong to the subclass Theria. This subclass includes animals that give birth to live young rather than laying eggs. Replace 'c. __________' with 'Theria'.

Identify the Family

Humans belong to the family Hominidae. This family includes humans, orangutans, gorillas, chimpanzees, and bonobos. These primates are known as great apes due to their large size, absence of a tail, and advanced cognitive abilities. Replace 'd.__________' with 'Hominidae'.

Identify the missing classification between Genus and Species

The missing classification between Genus (Homo) and Species is the actual species name. Humans belong to the species Homo sapiens. This species encompasses all living humans on Earth, regardless of race or ethnicity. Replace 'f. ___________' with 'sapiens'. Now we have the completed classification of humans: $$\begin{array}{cc}\text{Domain} && \text {Eukarya}\end{array}$$ $$\begin{array}{cc}\text{Kingdom} && \text {Animalia}\end{array}$$ $$\begin{array}{cc}\text{Phylum} && \text {Chordata}\end{array}$$ $$\begin{array}{cc}\text{Subphylum} && \text {Vertebrata}\end{array}$$ $$\begin{array}{cc}\text{Class} && \text {Mammalia}\end{array}$$ $$\begin{array}{cc}\text{Subclass} && \text {Theria}\end{array}$$ $$\begin{array}{cc}\text{Order} && \text {Primates}\end{array}$$ $$\begin{array}{cc}\text{Family} && \text {Hominidae}\end{array}$$ $$\begin{array}{cc}\text{Genus} && \text {Homo}\end{array}$$ $$\begin{array}{cc}\text{Species} && \text {sapiens}\end{array}$$

Key concepts

Biological Classification

Biological classification is the process scientists use to organize all living organisms into various categories. This system, often referred to as taxonomy, helps in understanding the relationships and origins of different species. The broadest category in taxonomy is the "Domain," which breaks down further into "Kingdom," "Phylum," "Class," "Order," "Family," "Genus," and finally, "Species." Each level of classification narrows down the characteristics that define an organism, showcasing the similarities and differences it shares with other species.

• Domain: The highest taxonomic rank, encompassing broad similarities.
• Kingdom: Divides domains into smaller, more specific groups.
• Phylum to Species: Further categorize organisms based on physical and genetic traits.

The purpose of this system is to make it easier to study and identify organisms, reflecting their evolutionary pathways and relationships. It allows scientists to communicate more effectively and standardizes the naming of species using Latin terms.

Chordata

The phylum Chordata consists of animals that at some point in their life cycle exhibit five main features. These include a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a post-anal tail. Not every chordate displays all these features as an adult, but they are typically present during some stage of development. Most chordates are vertebrates, meaning they have a backbone, but there are also some invertebrate chordates. Chordates are found in a wide variety of habitats around the world.
Within the chordate phylum, diversity is abundant:

• Notochord: A flexible rod providing structural support, present at some stage in all chordates.
• Dorsal nerve cord: Develops into the brain and spinal cord in many species.
• Pharyngeal slits: Openings in the throat area, which can form gills or structures in the head and neck.

Understanding the characteristics of chordates helps to delineate them from other, less complex organisms, providing insight into the complex evolutionary history shared by many vertebrates including humans.

Vertebrata

Vertebrata is a subphylum under the phylum Chordata and is characterized by the presence of a backbone or spinal column, which is a defining feature. Vertebrates include a vast array of species from fish and amphibians to birds and mammals. This subphylum is known for its incredible diversity and adaptability, thriving in nearly every environment on Earth.
Notable characteristics of vertebrates include:

• Spinal column: Provides support and protects the spinal cord.
• Complex nervous systems: More developed compared to invertebrates, enabling higher cognitive functions.
• Variety of forms: Includes aquatic and terrestrial species, exhibiting a range of body plans.

The backbone is a crucial advancement in the evolutionary history of vertebrates. It allows greater mobility and contributes to more complex behaviors and physical forms. Humans, as vertebrates, possess a well-developed brain protected by a skull, adding to the cognitive abilities that differentiate them from other species.

Hominidae

The family Hominidae, often referred to as great apes, includes humans, orangutans, gorillas, chimpanzees, and bonobos. Members of this family are recognized for their large body sizes, high intelligence, and the lack of a tail. Many hominids exhibit complex social behaviors and employ tools extensively, which are capabilities attributed to their advanced cognitive functions.
Key traits of the Hominidae family include:

• Large brain size: Contributing to higher cognitive abilities and complex social interactions.
• No tail: Unlike many other primates, which improves bipedal movement in humans.
• Tool use: Frequently observed in several species, showcasing problem-solving skills.

Humans belong to the genus Homo, which denotes their evolutionary path within this family. The evolution of erect walking (bipedalism) and other unique characteristics define the human species, separated from other great apes by remarkable cultural and linguistic developments.