In the world of biology, there are many sub-disciplines that focus on specific organisms or their characteristics. The study of invertebrates is one such area of focus. It has led to some confusion about whether insects are vertebrates or not. Indeed, while insects are arthropods and have an exoskeleton with multiple segments, they lack several other indicators of being a vertebrate. In this post, we will explore if insects are vertebrates and how scientists came to this conclusion.
Are Insects Vertebrates?
No. Insects are invertebrates. Vertebrates are animals with a backbone that include fish, amphibians, reptiles, birds, and mammals. The main characteristic of Vertebrates is their backbone or spinal column which contains nerves and blood vessels.
Why Are Insects Not Vertebrates?
1. Insects don’t have vertebral columns
If the word “vertebrate” makes you think of a particular part of the human body, you’re on the right track. The word “vertebrate” is a combination of two Latin words: vermis, which means “worm”, and vertebra, which means “winding”. The vertebrate group of animals is characterized by the presence of a special type of tissue called the “vertebral column”. In vertebrates, this column is located inside the spinal cord and makes up the backbone of the animal. In other words, it’s a series of bones that make up the spinal column. In insects, on the other hand, the vertebral column is located outside the body. If you look at an insect’s skeleton, you’ll see that the vertebral column is located outside the insect’s body.
2. Insects breathe using gills
Do you know that insects breathe through gills? That’s right! While most vertebrates breathe through their lungs, insects breathe through spiracles, tiny holes located on their abdomen. The spiracles lead to gills that are found inside the abdomen. Gills are special organs that are used for respiration in water. Insects breathe air, but they can also extract it from water. This is possible because of the gills. The gills contain tiny blood vessels that absorb oxygen from water. Apart from the spiracles and the gills, there are two other important organs involved in insect respiration. The first is the tracheal tubes, which are special tubes that transport oxygen throughout the insect’s body. The second is the book lungs, which are used for gas exchange when the insect is inside a cocoon.
3. Insects have no brainstem or cerebellum
The brainstem and the cerebellum are two important parts of the vertebrate brain. However, insects don’t have a brain stem and a cerebellum, which means that they don’t possess these parts of the vertebrate brain. The brainstem in vertebrates is an extension of the spinal cord. The brainstem controls the reflexes and autonomic functions such as breathing and heartbeat. In insects, however, the brain is found in the head, just like in humans. The cerebellum is the part of the brain responsible for motor control. Without a cerebellum, you can’t walk, run, or even swallow food. The only way for insects to survive is by living in a controlled state of constant motion and frenzy.
4. Insects have 3 pairs of jointed legs, not 2
Unlike vertebrates, whose legs are made up of two pairs of limbs, insects have three pairs. The two middle pairs of limbs are used for walking and the other pair is used for the reproductive organs. When contrasted with the vertebrates, this is the second important difference between the two groups. While insects have three pairs of legs, vertebrates have only two. Both insects and vertebrates have limbs, but these limbs are arranged in different ways. Another difference between insects and vertebrates is that insects have three pairs of legs while vertebrates have only two. A leg from each pair is used for walking at ground level. The other leg is used for transporting sperm to the female insects and for giving birth to the nymphs.
How Are Vertebrates Defined?
- Vertebrates are animals with a backbone. The backbone is a flexible structure that supports the animal’s body. There are two major subgroups of vertebrates – fish and tetrapods. The fish have a skeleton made of cartilage, while the tetrapods have a backbone made of vertebrae.
- The word “vertebrate” derives from the Latin “vertebra” meaning “joint” or “to bind together.” The vertebrate’s backbone is a flexible structure made of segments that are connected to each other. The segments of the backbone protect the spinal cord and associated nerves.
Why Do People Think Insects Are Vertebrates?
- There are many reasons why people think insects are vertebrates, but there are also several reasons why they are not. First, many insects have bilateral symmetry, which means two sides of the body are pretty much identical. Humans also have bilateral symmetry, which is a defining characteristic of vertebrates. Insects also have a central nervous system that is similar to that of vertebrates. Finally, insects have a closed circulatory system like vertebrates. This means their blood flows throughout the body and is not contained in vessels. However, there are reasons why insects are not vertebrates. Vertebrates have a certain number of genes that insects do not have. In addition, insects have an open circulatory system in which blood travels through an open system of tubes.
- Insects are invertebrate animals with an exoskeleton made of chitin. They have a set of segmented body parts and three pairs of jointed legs that allow them to move around. Furthermore, insects have a segmented thorax and abdomen that are separated by a narrow region called the petiole. The head is clearly separated from the rest of the body and is comprised of many segments (called an insect’s head capsule). The insect’s mouthparts are located on its head capsule, but there is no jaw or teeth to help chew food. Instead, insects use their mouthparts to suck or pierce food to consume it. The mouthparts also allow for other functions such as tasting food or smelling it before deciding if they want to eat it. Finally, insects do not is found inside the body. It is made up of a series of bones, including the ribs, the sternum (breastbone), and the clavicles.
How Did Scientists Determine If Insects are Vertebrates?
- Scientists were able to determine that insects have a nervous system that runs the length of the body, like a spinal cord in a vertebrate. This was a breakthrough in determining if insects are vertebrates.
- Researchers found the same genes for proteins in insects that run along a spinal cord. The genes were used to create a protein that glowed under a special microscope.
- The glowing protein was visible to the naked eye and allowed scientists to trace the nerve from the insects’ heads to their abdomen.
- Scientists then confirmed that the nerve in insects looks very similar to a spinal cord in a vertebrate. This makes insects a type of invertebrate that is a vertebrate.
Summing up
In the world of biology, there are many sub-disciplines that focus on specific organisms or their characteristics. The study of invertebrates is one such area of focus. It has led to some confusion about whether insects are vertebrates or not. Vertebrates are animals that have a spine and a spinal cord. Invertebrates are animals that do not have a spinal cord. The absence of a spine and the lack of an internal skeleton makes it difficult to determine the number of segments an invertebrate has. Scientists were able to determine that insects have a nervous system that runs the length of the body, like a spinal cord in a vertebrate.
