How is character polarity assigned for cladistics using outgroup comparison?Multiple choice question.A character is derived if it is shared with the outgroup.A character that is shared with the outgroup cannot be used to assign polarity.A character is homoplastic if it is shared with the outgroup.A character is ancestral if it is shared with the outgroup
Question
How is character polarity assigned for cladistics using outgroup comparison?Multiple choice question.A character is derived if it is shared with the outgroup.A character that is shared with the outgroup cannot be used to assign polarity.A character is homoplastic if it is shared with the outgroup.A character is ancestral if it is shared with the outgroup
Solution
The correct answer is: A character is ancestral if it is shared with the outgroup.
Here's the step by step explanation:
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In cladistics, character polarity is determined by comparing the group of organisms being studied (the ingroup) with a closely related but separate group of organisms (the outgroup).
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The outgroup is assumed to retain the ancestral state of the character traits, meaning the traits that were present in the common ancestor of both the ingroup and the outgroup.
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If a character is shared by both the ingroup and the outgroup, it is considered ancestral, or plesiomorphic. This is because the most likely explanation for both groups having the trait is that it was present in their common ancestor and passed down.
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Derived characters, or apomorphies, are those that have evolved in the ingroup and are not present in the outgroup. These are the traits that are used to determine the relationships within the ingroup.
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Homoplastic characters are those that appear to be shared by certain species, but are not due to common ancestry. Instead, they are the result of convergent evolution, where different species independently evolve similar traits due to similar environmental pressures, not because they inherited it from a common ancestor.
Similar Questions
Which of the following statements is true for all of the species that come after a branch point in a cladogram?Multiple choice question.They will no longer need an outgroup.They will share at least one shared derived character.They will share at least two shared derived characters.They do not share any derived characters.
When systematists polarize a character, they are determining whether Blank______.Multiple choice question.the trait is increasing or decreasing in magnitude over timethe trait is increasing or decreasing in complexity over timethe character is older and ancestral or if it is newer and derivedthe character displays geographical variation
A requirement of cladistics is that a grouping must include ________.species that can interbreedonly living speciesa common ancestor and all its descendantsspecies with shared traits
How does homoplasy affect cladistic analysis?Multiple choice question.It causes organisms to seem closely related when they are not.It has no effect because the homoplastic characters are exhibited by distant common ancestors.It causes organisms to seem even more distantly related than they are.
Only shared derived characters are instructive in determining evolutionary relationships among taxa because Blank______.Multiple choice question.they are essential to life and therefore may not be changed over the course of evolutionthey indicate recent evolutionary changes and are therefore exhibited in closely related taxathey are retained from a distant common ancestor and are therefore exhibited by all members of a cladethey are the most prevalent characters exhibited by members of a clade
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