Learn all about acclimatization. Understand what acclimatization is, examine a comparison of acclimation vs adaptation, and see examples of acclimatization.
Updated: 11/21/2023
Acclimatization in Biology | Definition, Methods & Examples
Table of Contents
- What is Acclimatization in Biology?
- Acclimatization vs Adaptation
- Methods of Acclimatization
- Acclimatization Examples
- Lesson Summary
Frequently Asked Questions
What is acclimatization?
Acclimatization is used interchangeably with acclimation. Acclimatization is known as the gradual and often reversible change in an organism due to environmental conditions.
What is an example of acclimatization?
Acclimatization is the gradual and often reversible change in an organism due to its environmental changes or stressors. An example of this is when salmon acclimate to different salinity levels as they migrate from saltwater to freshwater.
What are the two types of acclimatization?
There are two different types of acclimatization: biochemical acclimatization and morphological acclimatization. Biochemical acclimatization is the change in biological molecules in an organism, such as the change in enzyme production due to seasonal changes. Morphological acclimatization is the change in morphology or physical traits of an organism
Table of Contents
- What is Acclimatization in Biology?
- Acclimatization vs Adaptation
- Methods of Acclimatization
- Acclimatization Examples
- Lesson Summary
Planet Earth has a diverse array of climates and environments. These span from the deepest oceans to polar extremes, and from arid deserts to lush rich rainforests. To survive and be resilient to environmental change, lifeforms such as plants, animals, and fungi have developed diverse coping mechanisms.
Within biomes, which are regions of the planet with relatively similar climate and geographic features, there can be fluctuations in temperature and climate. To accommodate for this variation in climate within a given region, one of the coping mechanisms is a process known as acclimation, also referred to as acclimatization.
Understanding Acclimation
What is acclimatization or acclimation? These two words can be used interchangeably to describe an individual organism's ability to adapt to its environment's changes. Put simply, the definition of acclimate, or acclimatization, is the gradual and reversible change of an organism in response to a change in environment. Many organisms acclimate to various environmental factors. Plants, fungi, animals, and even humans have various ways of acclimating to new environmental conditions. Wild plants and animals have biological acclimations that allow them to survive when environmental conditions change. Humans also have ways of acclimating to various conditions, such as warm and cold temperatures, and even outer space. This lesson explores various ways different species acclimate to different environments and explains the difference between the definition of acclimation and adaptation.
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The definitions of acclimatization and adaptation sound similar; however, these two terms are used in biology to describe two different types of change that organisms undergo. To summarize, acclimatization is a biological change to an individual organism due to environmental changes or factors, while adaptation is a behavioral or genetic change in a species that is inherited over multiple generations. Here are some examples of each biological change.
Adaptations are the ways in which a species can live in a certain environment. Adaptations are genetic and lead to phenotypic—or visible—trait, differences that enable a species to be successful. For example, frogs and other amphibians are adapted to live both on land and in water. This is not something that any individual member of the species decided to do, but rather was developed over time due to natural selection pressures.
Thousands of years ago, an ancient ancestor of the frog lived in completely aquatic environments. That species found it beneficial to explore the resources that were available on land as well as the water, as the individual organisms that acquired both sets of resources were more likely to reproduce. Mutations in the genetics of the successful offspring eventually led to the speciation of amphibians and produced phenotypes such as four legs, lungs instead of gills, and the ability to move their heads. These physiological adaptations allow the frogs of today to be incredibly successful through the generational inheritance of genetically beneficial mutations.
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An organism's ability to acclimate is not measured through generations. The ability of an organism to acclimate may have physiological traits that are genetically inherited, but an individual organism's acclimatization takes place within an individual, not a population. This happens throughout the organisms' lifetime and not generationally. Additionally, acclimatization is generally reversible, whereas adaptations are not.
Following the definition of acclimatization previously mentioned, this also presents differences with homeostasis, which is an organism's ability to regulate the body's various conditions. For example, a human may shiver when cold, their body producing goosebumps. This is left over from when humans had more body hair, as goosebumps pull on the hair follicles of the skin of animals with fur, causing the hair to rise and provide temporary additional warmth. This is an example of homeostasis, and usually only lasts for a few minutes. Humans can, however, acclimate to the cold over a longer period. After a few weeks in the cold weather, people's metabolisms tend to increase to generate more heat, and after years of living in cold environments, some people increase the stores of fat cells, which are both examples of acclimatization.
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Now that acclimatization has been described in detail, it is important to note the different types of acclimatization. There are two main methods of acclimatization that various organisms undergo. One is biochemical acclimatization and the other is morphological acclimatization. Biochemical acclimatization refers to an organism's ability to change its biological molecules, such as enzymes, sugars, fats, and proteins. Morphological acclimatization refers to an organism's ability to change the morphology, or physical structures, depending on environmental conditions.
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Recall from above that there are two types of acclimatization: morphological and biochemical. The following acclimatization examples illustrate different ways organisms acclimate to their environment, as well as discuss the types of acclimatization organisms undergo.
An example of biochemical acclimation is when many species of fish, like the rainbow trout, acclimate to different temperatures gradually by producing different levels of enzymes. Enzymes are important biochemical molecules that work within the cells of all organisms. Studies on rainbow trout show that different enzymes are most efficient at different temperatures. This results in a biochemical restructuring of the body of rainbow trout in different seasons, with "winter" enzymes present in higher levels at lower water temperatures, and "summer" enzymes present in higher levels at higher water temperatures.
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An example of morphological acclimatization is represented in a species of cypress tree native to Japan and Asia that grows leaves of different shapes depending on the height of the leaf. This affects the amount of sunlight it receives and the amount of transpiration the leaf undergoes. Studies found that cypress leaves at the top of the tree, which see more light on average, were wider and thicker to maximize the tree's ability to undergo photosynthesis.
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What does acclimation, or acclimatization mean? It is the gradual, reversible change to the body of an organism because of variations in external environmental conditions, such as temperature, climate, salinity, acidity, and humidity. An organism's ability to acclimate is beneficial to the organism, as the environments on Earth change incrementally all the time. Acclimation allows for organisms to gradually change to better survive in the changed condition. An example of this is when salmon acclimate to different salinity levels as they migrate from saltwater to freshwater. Acclimation is different from adaptation, which is the genetic or phenotypic change of a population or species that is inherited over multiple generations, such as the evolution of frogs to be able to live on land and in water. Acclimation is also different from homeostasis, which is an organism's ability to regulate body functions such as producing goosebumps.
There are two different types of acclimatization: biochemical acclimatization and morphological acclimatization. Biochemical acclimatization is the change in biological molecules in an organism, such as the change in enzyme production due to seasonal changes. Morphological acclimatization is the change in morphology or physical traits of an organism, such as a cypress tree's leaves being bigger at the top of the tree due to increased sunlight.
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Additional Info
What Is Acclimation?
One big problem in studying ecology is that environments rarely, if ever, stay the same. Temperatures, precipitation, and food sources are always changing. One way that living things can handle these changes is through a process called acclimation.
Acclimation is a slow, reversible change to the body that allows an organism to handle a different environment. This change can occur over a few days, several weeks, or even months.
Acclimation and Adaptation
Acclimation may seem like a similar concept to adaption which is a feature acquired in a population that helps them live in a new environment. Adaptions can take generations to develop and happens to the population. Acclimation, on the other hand, is something that happens to an individual to allow it to survive when the environment changes.
Examples of Acclimation
Salmon
Salmon move from place to place to live out their life cycle. They begin their lives in freshwater streams, then move to saltwater oceans. As the salmon enter water that become saltier, they need to find a way to stay hydrated.
They have a very simple solution: they drink. This helps get their kidneys and gills working to get rid of the salt. Young salmon will stay at the edge between freshwater and saltwater for a few days or weeks in order to acclimate gradually.
When salmon near the end of their life cycle, they return to the freshwater streams to spawn, or reproduce. They'll again spend a few days to weeks in less and less salty water to become acclimated to their new environment.
Most fish need to live in either a saltwater or a freshwater environment. However, salmon are able to acclimate to the changing salt concentrations in the water as they migrate. This is reversible, because they can go from freshwater to salt water and back again. It is also gradual, because the change to the salmon doesn't happen instantly.
Listeria
While it's easy to think of big things, like animals, having to acclimate to their environments, small organisms need to do this too. Bacteria, for example, have to acclimate when they enter new environments.
Listeria monocytogenes is a bacterium that causes food poisoning in humans. It grows happily at our body temperature, infecting cells and making us sick. But one reason Listeria is able to make us sick is its ability to acclimate to cold temperatures.
When put into a refrigerator, instead of laying dormant like other bacteria species, Listeria will turn on a number of genes that allow it to continue growing and multiplying at lower temperatures. Listeria can also change the specific fatty acids in its membrane to prevent it from solidifying at low temperatures.
Once Listeria leaves the refrigerator and is eaten, it's suddenly in a warm, but acidic, environment. In order to survive the acid in your stomach, Listeria can acclimate and turn on its acid tolerance response.
Finally, once it is inside a human cell, it makes proteins that allow it to move from one cell to the next. As it goes through each of these different environments, Listeria needs to acclimate in order to continue on.
Acclimation in Humans
Even though humans prefer to alter our environments to fit our needs, we do sometimes need to alter ourselves to fit our environments.
Astronauts in outer space acclimate while living in low gravity. The percentage of red blood cells increases, because plasma (the liquid component of blood) decreases. Because there is no gravity, body fluids may redistribute.
The weightlessness of space leads to decreased muscle mass and bone degeneration. When on long missions in outer space, astronauts must exercise appropriately to prevent these changes from becoming extreme. When the astronaut returns to Earth, his or her body will need to re-acclimate to the normal gravity levels.
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Lesson Summary
Acclimation is a slow, reversible change to the body that allows an organism to handle a different environment. This is different than an adaptation, which is a feature acquired through generations of evolution to help a population live in a new environment. Acclimation can happen in animals, such as salmon that move between freshwater and saltwater. It can also happen in seemingly simple organisms, such as bacteria. Even human bodies need to acclimate to environmental changes, such as those that astronauts face.
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Acclimatization in Biology | Definition, Methods & Examples
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