What is bilateral symmetry?
bilateral symmetry, sometimes called the symmetry of reflection or mirror symmetry, means that an object or shape has two halves that are mirror images. For example, the main letter T and the triangle of Isosceles is bilaterally symmetrical. This term is most often used in biology, where it concerns organisms that have two symmetrical halves when they are divided only along one plane. This is called the saggital plane, the imaginary vertical plane that passes through the center of the body from the front to the back and divided it into the left and right sides. Most animal species have bilateral symmetry, including humans, and plants often have specific structures that are bilaterally symmetrical.
When the term "bilateral symmetry" is used more with reference to living beings than geometric forms, it is only approximate, because the biological growth process is not perfect and is not a perfect symmet. The location and structure of internal organs also may not be perfectly symmetrical to be considered the bodyfor bilateral symmetrical. For example, the human liver is on the right side of the abdominal cavity and it is perfectly normal that a person has asymmetry, such as one arm or leg that is slightly longer than the other.
bilateral symmetry is different from radial symmetry, which concerns a form that can be divided into roughly symmetrical halves along more than one plane. Starfish and jellyfish are examples of radially symmetrical animals. Bilateral symmetrical organisms, because they are symmetrical only on one plane, have different queues and back, but radially symmetrical organisms are not. Many plants have parts that are bilaterally symmetrical, such as tree leaves.
Animal species that have bilateral symmetry are referred to as bilateria. It is a huge category that includes most animal phyla and includes an extremely diverse number of organisms, from flat worms to human beings. ThreadArrše confirmed fossil of the organism in this group is considered to be more than 500 million years.
bilateral symmetry provides a number of advantages for organisms. It allows the body to be more efficient and therefore faster. In fact, it should be noted that species of animals that do not have bilateral symmetry are either very slow, as is the case with a starfish or completely sessile, as in the case of organisms such as mushrooms and see anemon.
The species, which has a body specializing in movement on a particular axis, rather than in all directions, can also concentrate most of its sensory organs and associated nerve tissue in front of its body instead of needing them to spread them in all directions. This specialization of the anterior body of the body, called cementalization, can lead to the development of more complex behavior and greater intelligence, as the nerve tissue becomes centralized. All organisms with more than a very basic nervous system are bilateria. Complex brains of people and other highly intelligent animals have in this procesu your evolutionary origin.