Download Standard 4 Review: Adaptation Big Ideas: • Species adapt to their

Standard 4 Review: Adaptation
Big Ideas:
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Species adapt to their environments over time by the process of natural selection
Natural selection is the result of organisms that are better adapted to an environment leaving
more offspring that inherit the advantageous traits
Evolution is the resulting change in the species over time due to this process
The form of an organism follows the functions it has to perform
Traits:
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A trait is anything that can be described about an organism
o This includes both physical qualities and behaviors
Traits are either inherited or acquired
o An inherited trait is coded for by DNA and can be passed down to offspring
o An acquired trait is gotten during life and cannot be passed down to offspring
A trait is considered an adaptation if it helps the organism to survive in an environment
Types of Reproduction:
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There are two types of reproduction: sexual and asexual reproduction
Sexual reproduction involves two parents which mix their genetic material to produce a new
combination in offspring
o Sexual reproduction is used by most large animals and some plants and fungi
o Sexual reproduction is best when the environment is changing or there are intense
pressures to adapt
Asexual reproduction involves one parent cloning itself to create genetically identical offspring
o Asexual reproduction is used by single-celled organisms (bacteria, protists, etc.), as well
as some plants and fungi
o Asexual reproduction is best when the environment is stable
Natural Selection
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The process of natural selection follows these steps:
o There must be differences between individuals in a species (variation)
o Those differences must result in individuals having differing numbers of offspring
(selection)
o Those offspring must be able to inherit the traits that made their parents successful
(inheritance)
o Over time, those organisms that leave more offspring come to dominate the species,
and so result in the evolution of the species (evolution)
Charles Darwin is credited for being the first person to suggest this mechanism for evolution
Mutation provides the raw material for differences in individuals
Artificial selection is the process by which humans breed organisms for use
o The only difference between artificial and natural selection is that it is humans are
selecting for traits rather than the environment
Form Follows Function:
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The appearance and structure of an organism is directly related to what it needs to do in order
to survive
Some examples given in class:
o A bird’s beak is related closely to its diet: hooked beaks for meat, thick beaks for
cracking nuts, long sharp beaks for spearing aquatic prey, or tubes for sucking nectar
o Camouflage in various organisms allow them to blend in with the surroundings
o Mimicry in various organisms allow them to mislead predators into thinking they are
dangerous
Natural Selection Diagram:
Example Adaptations: