Organic Evolution Test #1 D

What is the main idea behind grouping taxa together in phylogenetic inference?

• The idea is to group taxa together based on shared evolutionary history (closely related taxa should have more similar features).

• The idea is to group taxa together based on their geographic location only.

• The idea is to group taxa together based on their size and color.

• The idea is to group taxa together randomly without any criteria.

Fill in the blank: Only certain types of characters (features or traits) are useful in phylogenetic inference. These characters must be ________ (similarity due to descent from a common ancestor).

• homologous

• analogous

• convergent

• random

What are synapomorphies?

• Synapomorphies are the only homologies that are useful in estimating phylogenies.

• Synapomorphies are characteristics unique to a single species.

• Synapomorphies are traits that arise independently in unrelated groups.

• Synapomorphies are features shared by all living organisms.

What does the term 'derived' mean in evolutionary biology?

• Different (changed) from a common ancestor due to mutation.

• Unchanged from a common ancestor.

• A trait that is always harmful.

• A feature that is present in all living organisms.

What is a synapomorphy?

• A derived character shared within a clade (monophyletic group) and present in the clade’s common ancestor ('shared & derived').

• A character unique to a single species and not found in any relatives.

• A trait that is ancestral and found in all descendants of a distant common ancestor.

• A random mutation that does not affect evolutionary relationships.

According to the diagram, what is a synapomorphy in species 1 and 2?

• Dark coloration is a synapomorphy in species 1 and 2.

• Light coloration is a synapomorphy in species 1 and 2.

• Both species 1 and 2 lack synapomorphies.

• Species 1 and 2 share no common traits.

In this tree, dark coloration is an analogous trait in species 1 and 2 because it evolved twice in parallel, once along each branch. What is this type of trait called?

• Homoplasy

• Symplesiomorphy

• Synapomorphy

• Autapomorphy

If a derived trait (here, light coloration in species 3) has arisen recently and appears in only one of the two most closely related species, the two more distantly related species (species 1 and 2) share an ancestral trait (dark coloration). What is this shared ancestral trait called?

• Homoplasy

• Symplesiomorphy

• Synapomorphy

• Autapomorphy

Fill in the blank: A homoplasy is a trait that _________

• evolved twice in parallel, once along each branch (is an analogous trait that evolved independently in different lineages)

• is inherited from a common ancestor (is a homologous trait)

• is always beneficial to the organism

• is only found in extinct species

Symplesiomorphy refers to an ancestral character that is ancestral but is not shared by the two most closely related taxa.

• True

• False