Molecular Systematics in Phylogeny Inference

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What do systematists infer from molecular evidence?

Geographical distribution

Predator-prey relationships

Habitat preference

Phylogeny (correct)

Why should DNA and amino acid sequences be more similar between species that have recently branched from a common ancestor?

Due to the reflection of common ancestry in homology (correct)

Diverse environmental pressures

Loss of genetic information over time

Random mutation rates in DNA sequences

Why is molecular systematics valuable in assessing phylogenetic relationships?

It is used for determining geographical distribution

It provides information on species habitat preferences

It relies solely on morphological divergence

It can evaluate relationships beyond what comparative anatomy offers (correct)

Which type of groups benefit the most from molecular systematics due to limited morphological divergence?

Closely related groups (D) Signup and view all the answers

What is the basis for most molecular systematics analysis?

Comparison of nucleotide sequences in DNA or RNA (A) Signup and view all the answers

How do systematists construct cladograms using DNA sequence analysis?

Branch points defined by mutations in DNA sequence (B) Signup and view all the answers

What makes it easier to define identity using molecular data compared to morphological data?

Molecular data are less subject to homoplasy (D) Signup and view all the answers

In a rooted tree, what does the root represent?

Hypothetical ancestors (B) Signup and view all the answers

What is the main difference between a rooted and an unrooted tree?

Directionality in terms of evolutionary time (C) Signup and view all the answers

What is the significance of the phosphate group, sugar, and nitrogenous base in nucleotide structure?

They hook nucleotides together in DNA formation (A) Signup and view all the answers

Why can long branch attraction occur in molecular data analysis?

As a result of errors from fast mutation rates and limited characters (C) Signup and view all the answers

Which type of tree allows us to define ancestor-descendant relationships between nodes?

Rooted tree (B) Signup and view all the answers

What do terminal nodes represent in a tree?

Operational taxonomic units (D) Signup and view all the answers

What regions of DNA evolve relatively rapidly and are useful for assessing closely related species or populations?

mtDNA regions (C) Signup and view all the answers

In terms of evolutionary relationships, what does an unrooted tree lack compared to a rooted tree?

Specification of ancestors and descendants (B) Signup and view all the answers

Why do insertions and deletions in DNA sequences create challenges when establishing homology?

They introduce base changes that are difficult to align (C) Signup and view all the answers

How do two closely related species primarily differ in their DNA sequences?

By differing in multiple bases and having insertions or deletions (D) Signup and view all the answers

What is the core principle of Maximum Parsimony?

Minimizes evolutionary changes (B) Signup and view all the answers

Which method is statistically robust and incorporates evolutionary models?

Maximum Likelihood (ML) (B) Signup and view all the answers

What is a disadvantage of using Unweighted Pair-Group Method with Arithmetic Mean (UPGMA)?

Not statistically rigorous (C) Signup and view all the answers

When applying parsimony to a problem in molecular systematics, which dataset size is more suitable for Maximum Parsimony according to the text?

Smaller datasets, qualitative analysis, exploration, uncertain model assumptions (C) Signup and view all the answers

What does Neighbor Joining (NJ) primarily do in constructing phylogenetic trees?

Iteratively joins closest sequences, updates distances (B) Signup and view all the answers

In the context of Maximum Likelihood (ML), what does 'maximizes probability of observed data under a model' mean?

Selects the tree with the highest likelihood score (C) Signup and view all the answers