Question

(b) Using the template of the phylogenetic tree, circle the lineages that share node

Answer 1

Complete question:

(b) Using the template of the phylogenetic tree, circle the lineages that share node A. You will find the tree in the attached files.

Answer:

The Lineages that share node A are  

• Chinese river dolphin
• Amazon river dolphin
• La Plata river dolphin
• Dolphins
• Narwhal
• Porpoises

Explanation:

The phylogenetic tree is composed of,

• Lineages → These are the taxonomic groups of interest placed in the extremes of the lines called branches.
• Nodes → These are the ramification points, which are also known as divergence points. They represent the location of the most recent common ancestor.
• Root → This is the older common ancestor that all lineages share. The first one in the tree.

- Two or more lineages are more related to each other if they share a recent common ancestor. This means that they all diverge from the same node.

- Two or more lineages are less related to each other if they lack a recent common ancestor. This is, the node from which these lineages diverge is placed far away in the tree.

There are also different phylogenetic relationships between lineages.

• Apomorphies → Occur when the involved lineages share a trait that they inherited from their most recent common ancestor. This trait evolved for the first time in this ancestor. → This relationship is a homology.
• Plesiomorphies → occur when the involved lineages share a trait inherited from a common ancestor, but that is older concerning the present traits exhibited by other descendants of the same common ancestor. → This relationship is a homology.
• Homoplasy → Lineages share a trait that evolved independently in each group. → This relationship is an analogy.