Monophyletic, Paraphyletic, Polyphyletic Quiz

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Questions and Answers

Which group is considered a monophyletic group (clade)?

Group II

Group IV

Group III

Group I (correct)

Which group is considered a paraphyletic group?

Group I

Group III

Group IV

Group II (correct)

Which group is considered a polyphyletic group?

Group IV

Group II

Group I

Group III (correct)

What is the main characteristic of a monophyletic group?

It consists of an ancestral species and all of its descendants. Signup and view all the answers

What is the main characteristic of a paraphyletic group?

It consists of an ancestral species and some of its descendants. Signup and view all the answers

What is the main characteristic of a polyphyletic group?

It consists of species that have a common ancestor but not all of its descendants. Signup and view all the answers

Which group is not considered a monophyletic group?

Group III Signup and view all the answers

Which group does not include all the descendants of the common ancestor?

Group II Signup and view all the answers

Which group includes species that have different common ancestors?

Group IV Signup and view all the answers

Which group consists of an ancestral species and all of its descendants?

Group I Signup and view all the answers

Which of the following statements is true about shared ancestral characters?

Shared ancestral characters originated in an ancestor of the taxon. Signup and view all the answers

What is the difference between shared ancestral and shared derived characters?

Shared ancestral characters originated in an ancestor of the taxon, while shared derived characters are evolutionary novelties. Signup and view all the answers

Which of the following is an example of a shared derived character?

The presence of a backbone in mammals and all other vertebrates. Signup and view all the answers

What is an ingroup?

A group of species that are being studied. Signup and view all the answers

What is an outgroup?

A group of species closely related to but not part of the species being studied. Signup and view all the answers

What can the branch lengths in a phylogenetic tree indicate?

The time at which certain species diverged from a common ancestor. Signup and view all the answers

Which group of organisms is polyphyletic?

Even-toed ungulates. Signup and view all the answers

What does it mean for a group to be polyphyletic?

The group does not include the most recent common ancestor of its members. Signup and view all the answers

What can help to infer evolutionary relationships?

The presence of shared derived characters. Signup and view all the answers

Which of the following is an example of a shared ancestral character?

The presence of a backbone only in vertebrates. Signup and view all the answers

Study Notes

Phylogenetic Groups

Monophyletic Group (Clade): Comprises an ancestral species and all its descendants, forming a complete branch on the tree of life.
Paraphyletic Group: Consists of an ancestral species and some, but not all, of its descendants, leading to an incomplete representation of a lineage.
Polyphyletic Group: Includes species that do not share a recent common ancestor, grouping together organisms based on similar traits rather than common ancestry.

Characteristics of Groups

Main Characteristic of Monophyletic Group: Contains all descendants from a common ancestor, illustrating true evolutionary relationships.
Main Characteristic of Paraphyletic Group: Lacks some descendants of a common ancestor, resulting in a fragmented view of evolution.
Main Characteristic of Polyphyletic Group: Groups organisms that may share physical traits yet have diverged from different ancestral lines.

Evolutionary Relationships

Groups Not Considered Monophyletic: Paraphyletic and polyphyletic groups lack the completeness of a true clade.
Group Lacking All Descendants: Paraphyletic group does not include every descendant of a common ancestor.
Group with Different Common Ancestors: Polyphyletic group consists of species with varied evolutionary backgrounds.

Shared Characters

Shared Ancestral Characters: Traits inherited from a distant ancestor, applicable to a broader range of organisms in a lineage.
Difference Between Shared Ancestral and Derived Characters:
- Shared Ancestral Characters are primitive traits shared by all members of a clade.
- Shared Derived Characters are traits that have evolved more recently and characterize a more specific group.

Additional Terms

Example of Shared Derived Character: The presence of feathers in birds, distinguishing them from other reptiles.
Ingroup: The group of organisms being studied, which share certain derived traits.
Outgroup: A species or group outside of the ingroup, used as a reference point in phylogenetic analysis.

Phylogenetic Trees

Branch Lengths: Indicate the amount of evolutionary change or time between nodes in a phylogenetic tree.
Polyphyletic Groups in Organisms: Often occur in classifications such as marine mammals (whales, dolphins) grouped with fish, which do not share a common ancestor.
Inference of Evolutionary Relationships: Analyzing shared derived characters can help in determining how closely related different organisms are.

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Description

Test your knowledge of cladistics with this quiz! Learn about monophyletic, paraphyletic, and polyphyletic groups and how they are classified in evolutionary biology. Can you identify the correct classification for the given species? Find out now!