Morphology & Natural Selection
Form, also known as morphology, refers to the physical structure, shape and size of an organism, both internal and external. Organisms have their unique morphology due to a process of gradual evolution over millions of years. Mutations happen seemingly at random. Some of those mutations are beneficial and help living things to better survive, while others do not. When a mutation is beneficial, that altered organism will have an advantage over others of its species as it competes for resources. In this way, some traits endure in species and others fade away.
The most famous contributor to our understanding of this concept was Charles Darwin. Through his experiences documenting variations in animals while exploring South America and the South Pacific, he formed his theory of natural selection. Natural selection asserts that living things survive or fail to survive due to differences in their traits. Darwin published several books, but most famously first expressed his ideas in his 1859 publication On the Origin of Species. As an example, Darwin observed that there were huge variations in finches in the Galapagos Islands. Each species was a different size and had a differently shaped beak. He noted that the size and shape of each beak was ideal for the particular food source of each species, whether nuts, insects or fruit. Darwin asserted that the function of each species perfectly followed its form.
The most obvious examples of form and function are the ones we've already discussed - that individual living things have specific forms that allow them to fulfill certain functions and survive. However, this is also true of the various components of an ecosystem. An ecosystem can be split into abiotic (or nonliving) and biotic (or living) components. Even abiotic components like soil, rain, and wind have important functions in an environment. The soil holds and cycles nutrients for plants. Rain provides water to quench the thirst of both plants and animals. Wind scatters the seeds of plants, allowing new plants to germinate. All the different parts of an ecosystem work together in harmonious balance.
In nature, some species have special relationships that allow them both to thrive. For example, people benefit from the 'good' bacteria in their intestines, which keep pathogens at bay. Also, cleaner fish get nutrients in the form of parasites and dead skin cells while larger creatures such as whales (and even people!) get the grooming they need to stay healthy. These kinds of two-way beneficial relationships are called mutualism, or symbiosis.
Lesson Summary
Let's review…
Form and function in science refer to the idea that the morphology, or structure, of a thing is directly related to its function. Animals and plants have traits which allow them to survive. While scientists once thought that that form followed function in nature, the prevailing scientific theory now is that function follows form due to processes surrounding evolution and Darwin's theory of natural selection. Changes to organisms happen randomly through mutations, and mutations that are beneficial survive through generations. In a wider sense, ecosystems also have complementary form and function, both biotic and abiotic components. Some species interact in such a way that they both help each other to thrive, which is known as mutualism.
