Adaptations to the Environment From Buckle Down Mississippi

Adaptations to theAdaptations to theEnvironmentEnvironment

From Buckle Down MississippiFrom Buckle Down Mississippi

You may know that some animals, You may know that some animals, such as such as chameleonschameleons and and octopusesoctopuses, , can change the color of their skin. can change the color of their skin.

This ability is good for This ability is good for camouflagecamouflage, , or blending into the surroundings. or blending into the surroundings.

Animals with the ability to change Animals with the ability to change the color of their skin often use it to the color of their skin often use it to avoid predatorsavoid predators or to or to surprise their surprise their prey.prey.

AdaptationsAdaptations

The ability to change skin color is The ability to change skin color is one example of an one example of an adaptationadaptation. .

An An adaptation adaptation is any trait that helps is any trait that helps the individuals of a species the individuals of a species respond respond toto and and survive withinsurvive within an an environment. environment.

In this lesson, we will look at some In this lesson, we will look at some common adaptations that help common adaptations that help animals and plants animals and plants survivesurvive in their in their environments.environments.

AdaptationsAdaptations

Some Animals are Some Animals are adapted to adapted to attract attract attention attention

To attract members of To attract members of their own species for their own species for mating mating purposes orpurposes or

As a As a warningwarning to possible to possible enemies (predators) of enemies (predators) of their bitter or smelly their bitter or smelly secretions or a powerful secretions or a powerful sting.sting.

Adaptations- Adaptations- Attention Attention Please!Please!

The Mexican milk snake, is not The Mexican milk snake, is not poisonouspoisonous, , but it looks like the but it looks like the Texas coral snakeTexas coral snake which predators avoid because a coral which predators avoid because a coral

snakesnake’’s bite can be serious.s bite can be serious. The Mexican milk uses The Mexican milk uses mimicrymimicry to avoid to avoid

being eaten.being eaten.

AdaptationsAdaptations--Mimicry: Looking Mimicry: Looking DangerousDangerous

If red touches black, If red touches black, you’re ok Jack. If you’re ok Jack. If red touches yellow, red touches yellow, that’s the dangerous that’s the dangerous fellowfellow

Other interesting examples of Other interesting examples of mimicry include:mimicry include:

Moths and Butterflies with large Moths and Butterflies with large eye spots on their wings that eye spots on their wings that look like owllook like owl’’s eyess eyes

A moth that mimics hornets. It A moth that mimics hornets. It even has what looks like a even has what looks like a stinger on its abdomen.stinger on its abdomen.

AdaptationsAdaptations--Mimicry: Looking Mimicry: Looking DangerousDangerous

HomeostasisHomeostasis

When you think of an organism When you think of an organism interacting with its environment, you interacting with its environment, you might first think of the external might first think of the external environmentenvironment——the the air, water, air, water, and/orand/or land land in which the organism lives. in which the organism lives.

But an organism must also respond to But an organism must also respond to changes inside itself, called its changes inside itself, called its internal internal environment. environment.

In general, organisms must keep their In general, organisms must keep their internal environments fairly internal environments fairly stable.stable.

Take the human body as an Take the human body as an example. The human body example. The human body works best when its works best when its temperature is around temperature is around 37° 37° CC. .

If a human body gets too If a human body gets too warm, it releases some of warm, it releases some of that heat by that heat by sweatingsweating. .

If a human body gets too If a human body gets too cold, it produces more heat cold, it produces more heat for itself by for itself by shiveringshivering. .


The ability to maintain a constant The ability to maintain a constant internal environment is called internal environment is called homeostasishomeostasis. .

(Homeo- (Homeo- means "means "steadysteady" and " and stasis stasis means "means "statestate.").")


Different animals maintain Different animals maintain homeostasishomeostasis in different ways. in different ways.

Again, consider an animal's internal Again, consider an animal's internal temperature. temperature.

Mammals have bodies that Mammals have bodies that automatically maintainautomatically maintain their internal their internal temperatures. temperatures.

For this reason, they are called For this reason, they are called warm-blooded animals. warm-blooded animals.


Other animals, such as Other animals, such as reptilesreptiles, , maintain their internal temperatures maintain their internal temperatures through through behaviorbehavior. .

If a lizard gets If a lizard gets too warmtoo warm, for example, , for example, it will go into the it will go into the shadeshade to cool off. to cool off.

If a lizard gets If a lizard gets too coldtoo cold, it will , it will baskbask in in the sun.the sun.

Animals that maintain their body Animals that maintain their body temperatures through behaviors are temperatures through behaviors are called called cold-blooded animalscold-blooded animals..


Adaptations to External Adaptations to External EnvironmentsEnvironments

Of course, organisms must also respond to Of course, organisms must also respond to changes in their changes in their external environmentsexternal environments, or , or the places in which they live. the places in which they live.

Many places on the Earth have seasonsMany places on the Earth have seasons——months of months of rainy weather rainy weather followed by followed by months of months of dry weatherdry weather, or, or

months of months of cold temperaturescold temperatures followed by followed by months of months of warm temperatureswarm temperatures

Seasonal changes usually affect the Seasonal changes usually affect the amount of amount of food food available in an available in an environment. environment.

Organisms have evolved different Organisms have evolved different behavioral responsesbehavioral responses to the changing to the changing availability of food in their availability of food in their environments.environments.


HibernationHibernation is a condition in is a condition in which an animal remains in a which an animal remains in a sleep-like statesleep-like state for weeks, months, for weeks, months, or even years. or even years.



Black bearsBlack bears, for example, fatten , for example, fatten themselves up during the themselves up during the summersummer months when food is months when food is plentifulplentiful. . During During winterwinter, they hibernate and , they hibernate and slowly use up the slowly use up the food energyfood energy stored in their stored in their fatfat. .

Some Some insectsinsects and and reptilesreptiles also also hibernate when temperatures are hibernate when temperatures are lowlow and food and water are and food and water are scarce.scarce.

MigrationMigration is is anotheranother behavior for dealing with behavior for dealing with limited food availabilitylimited food availability. .


Birds, for example, rely on Birds, for example, rely on insectsinsects, , nectarnectar, and , and seedsseeds for food. for food.

Because flowers and insects are not Because flowers and insects are not easy to find during easy to find during coldcold or or drydry months, many species of bird months, many species of bird migratemigrate to areas where they can find to areas where they can find such such foodfood. .

Some animals also migrate to Some animals also migrate to special special placesplaces for the purpose of for the purpose of matingmating and and giving birthgiving birth to their offspring. to their offspring.

Adaptations to Adaptations to External EnvironmentsExternal Environments

Adaptations and EvolutionAdaptations and Evolution

Offspring that inherit a Offspring that inherit a helpful helpful adaptationadaptation have a better chance of have a better chance of surviving surviving than offspring that do not than offspring that do not inherit the trait. inherit the trait.

Let's examine what happens to a Let's examine what happens to a crab population over many crab population over many generations when generations when natural selectionnatural selection favors an adaptation.favors an adaptation.

Suppose that a crab population lives Suppose that a crab population lives on an on an islandisland where a where a predator birdpredator bird has been introduced. has been introduced.

Most of the crabs have Most of the crabs have soft shellssoft shells, , but a few have but a few have hard shellshard shells. .

The predator bird has an The predator bird has an easier timeeasier time eating the eating the soft-shelledsoft-shelled variety. variety.

The The hard-shelledhard-shelled crabs begin to crabs begin to live live longerlonger and and reproduce morereproduce more than the than the soft-shelled crabs. soft-shelled crabs.


Over many Over many generationsgenerations, most of crabs , most of crabs have have hard shellshard shells and very few have soft and very few have soft shells. shells.

When When natural selectionnatural selection favors the favors the survivalsurvival and and reproductionreproduction of hard- of hard-shelled crabs they become more shelled crabs they become more commoncommon


The change that took place in the crab The change that took place in the crab population is an example of population is an example of evolutionevolution. .

Any Any changechange in a population's genetic in a population's genetic makeup that takes place makeup that takes place over many over many generationsgenerations is called is called evolutionevolution. .

Species change over time as Species change over time as certain traitscertain traits become become more commonmore common in the population in the population and and others less commonothers less common. .


There is lots of evidence that present-day There is lots of evidence that present-day species have species have descendeddescended from other from other species through species through evolutionevolution. .

DNA DNA evidenceevidence has demonstrated that has demonstrated that species who share the most species who share the most traitstraits also also share the most share the most DNA. DNA.

Because DNA is Because DNA is inherited,inherited, these different these different species must be related through a species must be related through a common ancestor.common ancestor.


Adaptations in the Fossil Adaptations in the Fossil RecordRecord

As recently as one million years ago, at least As recently as one million years ago, at least 10 species of elephant walked the Earth, 10 species of elephant walked the Earth, including eight species of mammoth. including eight species of mammoth.

Today, only three elephant species still exist:Today, only three elephant species still exist:

* two types of African elephant and* two types of African elephant and

* the Asian elephant.* the Asian elephant. Both species of African elephant are now Both species of African elephant are now

endangered.endangered.

One reason for the reduced number of One reason for the reduced number of elephants is that most species were elephants is that most species were specialistsspecialists. .

A species that specializes is A species that specializes is adaptedadapted to a very to a very particular environmentparticular environment. .

If that environment If that environment changes quicklychanges quickly, a species , a species that specializes typically that specializes typically cannot adaptcannot adapt quickly quickly enough to survive. enough to survive.

Adaptations in the Adaptations in the Fossil RecordFossil Record

Wooly mammothsWooly mammoths, for example, thrived in , for example, thrived in ice ice ageage conditions, but their numbers began conditions, but their numbers began dropping as dropping as global temperaturesglobal temperatures rose. rose.

The three species of elephants alive today, on The three species of elephants alive today, on the other hand, can the other hand, can survivesurvive in a in a wider rangewider range of of climatesclimates than the wooly mammoths could. than the wooly mammoths could.


Probably the most important environmental change, Probably the most important environmental change, however, was the rise of however, was the rise of humanshumans as the as the top predatortop predator on the planet. on the planet.

Slow-movingSlow-moving mammoth herds were no match for mammoth herds were no match for packs of packs of swift, cunning human huntersswift, cunning human hunters. .

Between Between 12,000 and 10,000 years ago12,000 and 10,000 years ago, most species , most species of large mammal went of large mammal went extinctextinct in North and South in North and South America. America.


This This mass extinctionmass extinction included the Columbian included the Columbian mammoth, the Wooly mammoth, and the mammoth, the Wooly mammoth, and the American mastodon. American mastodon.

Other species that went extinct included a Other species that went extinct included a beaver the size of a bear, five species of beaver the size of a bear, five species of horse, three deer species, three species of horse, three deer species, three species of musk ox, two species of wild ox, two species of musk ox, two species of wild ox, two species of giant armadillo, many species of giant sloth, giant armadillo, many species of giant sloth, and the only species of American camel.and the only species of American camel.


BlameBlame for these extinctions cannot be laid solely for these extinctions cannot be laid solely upon humans. upon humans.

Changes to the Changes to the global climateglobal climate also played an also played an important role. important role.

Nonetheless, mammalian life in the Americas was Nonetheless, mammalian life in the Americas was much more much more diversediverse and far more and far more massivemassive before the before the arrival of humans.arrival of humans.


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Adaptations to the Environment From Buckle Down Mississippi