Cladistics - C3 PDF

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Cladistics C3...

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Which is the basal group:

Lamprey

basal is the direction of the base (or root) of a rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Each node in the tree corresponds to a clade

A basal group in the stricter sense forms a sister group to the rest of the larger clade, as in the following case: {{.\BASAL.JPG}} In phylogenetics, the term basal can be objectively applied to clades of organisms, but tends to be applied selectively and more controversially to groups or lineages[n 8] thought to possess ancestral characters, or to such presumed ancestral traits themselves. In describing characters, "ancestral" or "plesiomorphic" are preferred to "basal" or "primitive", the latter of which may carry false connotations of inferiority or a lack of complexity.

What are the Similarities Between Monophyletic Paraphyletic and Polyphyletic? All these terms are used to define taxa of organisms. All terms are used to define a group of organisms. When defining, the most recent common ancestor is considered in all groups. All these groups explain the relatedness of the organisms.

What is the Difference Between Monophyletic Paraphyletic and Polyphyletic? ==== Monophyletic vs Paraphyletic vs Polyphyletic ==== Monophyletic Monophyletic group is a taxon that consists ancestor and all its descendants. Paraphyletic Paraphyletic group is a taxon that consists ancestor and some of its descendants. Polyphyletic Polyphyletic group is a taxon that consists who are from a different recent common ancestor. This group common ancestor.

of a most recent common of a most recent common of unrelated organisms lacks a most recent

==== Descendants of a Common Ancestor ==== Monophyletic Monophyletic group includes all descendants of the ancestor. Paraphyletic Paraphyletic group does not include all the descendants of the

ancestor. Polyphyletic ancestor.

Polyphyletic group does not include all the descendants of the

==== Common Ancestor ==== Monophyletic Monophyletic group has a common ancestor. Paraphyletic Paraphyletic group has a common ancestor. Polyphyletic Polyphyletic group lacks a common ancestor. ==== Based On ==== Monophyletic Monophyletic is a group based in synapomorphy. Paraphyletic Paraphyletic is a group based in symplesiomorphy. Polyphyletic Polyphyletic is a group based on convergence. ==== Nature ==== Monophyletic Monophyletic group is a natural taxon. Paraphyletic Paraphyletic group is a natural taxon. Polyphyletic Polyphyletic group is an unnatural assemblage of organisms.

SUMMARY The monophyletic group consists of a most recent common ancestor and its entire descendants. The paraphyletic group consists of a most recent common ancestor and some of its descendants. The polyphyletic group is an unnatural assemblage of unrelated organisms who lack a most recent common ancestor. This is the difference between monophyletic, paraphyletic and polyphyletic.

Polytomies arise when the relationships between a group of taxa are unresolved. For example, look at the polytomy in the tree below {{.\Slide14.jpg}} The relationships between species 3 , 4, and 5 are unresolved. Species 4 and 5 could be a sister group, with species 3 as the sister group to their clade.

In the following cladogram, which groups are most closely related?

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A. Beetles and Ants B. Flies and Beetles C. Moths and Flies

You are making a cladogram of fruit. You have 4 fruits: a banana, and orange, a red apple, and a green apple. On appearance alone, which of these is an outgroup, and which two belong on the node furthest from the start of the diagram? A. Orange; Banana and Red Apple B. Banana; Orange and Red Apple C. Banana; Red Apple and Green Apple

Look at the cladogram referenced in question #1. Which of the following characteristics is a symplesiomorphy of the cladogram? A. Wings B. A tongue to gather nectar C. Wings that fold under a hard shell

A group of species comprising an ancestral species and all its descendants is a: Clade Common Ancestor Most Parsimonious Group Sister Group Basal group

ANSWERS C C A Clade...