AP Biology Flashcards: Phylogeny

What this deck covers

This deck focuses on Phylogeny, giving you a quick way to review the definitions, rules, and examples that matter most for AP Biology.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What is the difference between rooted and unrooted trees?

Answer: Rooted trees have a designated root; unrooted trees do not. Rooted trees show directionality of evolutionary time.

Flashcard 2: What is the distinction between taxonomy and phylogeny?

Answer: Taxonomy classifies organisms; phylogeny studies their evolutionary relationships. Taxonomy groups organisms; phylogeny traces their evolution.

Flashcard 3: What is a consensus tree?

Answer: A tree that summarizes the common features of a set of trees. Shows areas of agreement among different phylogenetic analyses.

Flashcard 4: What is a shared ancestral character?

Answer: A character that originated in an ancestor of the taxon. Plesiomorphies are inherited from earlier common ancestors.

Flashcard 5: What is the purpose of bootstrap analysis in phylogenetics?

Answer: To assess the reliability of inferred phylogenetic trees. Statistical resampling method to test tree robustness.

Flashcard 6: What is a molecular marker in phylogenetics?

Answer: A specific DNA sequence used to study genetic relationships. Provides data points for comparing evolutionary divergence.

Flashcard 7: Which type of data is commonly used to construct phylogenetic trees?

Answer: Molecular data, such as DNA, RNA, or protein sequences. DNA sequences provide objective measures of evolutionary change.

Flashcard 8: Define clade.

Answer: A clade is a group of organisms that includes an ancestor and all its descendants. Also called a monophyletic group in phylogenetics.

Flashcard 9: What does a branch point in a phylogenetic tree represent?

Answer: A branch point represents a common ancestor of the lineages that diverge from it. Also called a node; where lineages split in evolutionary time.

Flashcard 10: What is meant by 'tree topology'?

Answer: The branching pattern of a phylogenetic tree. The arrangement of branches showing evolutionary relationships.

Flashcard 11: What is the significance of a shared derived character?

Answer: It indicates a common ancestry among the organisms sharing it. Synapomorphies define clades and evolutionary relationships.

Flashcard 12: Identify the root of a phylogenetic tree.

Answer: The root represents the most recent common ancestor of all taxa in the tree. The starting point showing the oldest common ancestor.

Flashcard 13: How is molecular clock used in phylogenetics?

Answer: It estimates time of evolutionary events based on mutation rates. Assumes constant mutation rates to calculate divergence times.

Flashcard 14: What role does bioinformatics play in phylogenetics?

Answer: It assists in analyzing genetic data to infer evolutionary relationships. Provides computational tools for large-scale phylogenetic studies.

Flashcard 15: What is a shared ancestral character?

Answer: A character that originated in an ancestor of the taxon. Plesiomorphies are inherited from earlier common ancestors.

Flashcard 16: Define outgroup in phylogenetic analysis.

Answer: A species or group of species closely related but not part of the group under study. Used to root trees and determine character polarity.

Flashcard 17: Define clade.

Answer: A clade is a group of organisms that includes an ancestor and all its descendants. Also called a monophyletic group in phylogenetics.

Flashcard 18: Define the term 'phylogenetic signal'.

Answer: The pattern of trait resemblance among species due to shared ancestry. Strong signal indicates reliable phylogenetic inference.

Flashcard 19: What is a monophyletic group?

Answer: A group of organisms that consists of an ancestor and all its descendants. Same as a clade; represents natural evolutionary groups.

Flashcard 20: Define 'node' in the context of a phylogenetic tree.

Answer: A point on a tree where a lineage splits into two or more lineages. Branch points where evolutionary splitting occurs.

Flashcard 21: What is a paraphyletic group?

Answer: A group that includes an ancestor but not all of its descendants. Creates artificial groups that exclude some descendants.

Flashcard 22: What is a character matrix?

Answer: A table showing the presence or absence of traits across taxa. Organizes trait data for phylogenetic analysis.

Flashcard 23: What is meant by 'tree topology'?

Answer: The branching pattern of a phylogenetic tree. The arrangement of branches showing evolutionary relationships.

Flashcard 24: What is a reticulate evolution?

Answer: Evolution involving the merging of different lineages through hybridization. Creates network-like patterns rather than simple trees.

Flashcard 25: What role does bioinformatics play in phylogenetics?

Answer: It assists in analyzing genetic data to infer evolutionary relationships. Provides computational tools for large-scale phylogenetic studies.

Flashcard 26: What is a cladogram?

Answer: A type of diagram that shows relationships among species based on shared characteristics. Focuses on branching patterns without time or rate information.

Flashcard 27: What is an ultrametric tree?

Answer: A tree where all paths from the root to the leaves are of equal length. Assumes molecular clock with constant evolutionary rates.

Flashcard 28: What are synapomorphies?

Answer: Shared derived characters used to construct phylogenetic trees. Define clades by showing evolutionary novelties.

Flashcard 29: What is a phylogenetic tree?

Answer: A diagram that represents evolutionary relationships among organisms. Branch patterns show how species diverged from common ancestors.

Flashcard 30: What is the significance of a shared derived character?

Answer: It indicates a common ancestry among the organisms sharing it. Synapomorphies define clades and evolutionary relationships.

Flashcard 31: What are orthologs?

Answer: Genes in different species that evolved from a common ancestral gene. Share common ancestry and similar functions across species.

Flashcard 32: Define outgroup in phylogenetic analysis.

Answer: A species or group of species closely related but not part of the group under study. Used to root trees and determine character polarity.

Flashcard 33: What is an evolutionary tree?

Answer: A diagram that represents hypotheses about the history of species divergence. Shows branching patterns of species through time.

Flashcard 34: What are orthologs?

Answer: Genes in different species that evolved from a common ancestral gene. Share common ancestry and similar functions across species.

Flashcard 35: Which type of data is commonly used to construct phylogenetic trees?

Answer: Molecular data, such as DNA, RNA, or protein sequences. DNA sequences provide objective measures of evolutionary change.

Flashcard 36: What is horizontal gene transfer?

Answer: The movement of genes between unrelated species. Can complicate phylogenetic trees by mixing lineages.

Flashcard 37: What is the difference between rooted and unrooted trees?

Answer: Rooted trees have a designated root; unrooted trees do not. Rooted trees show directionality of evolutionary time.

Flashcard 38: What is homology?

Answer: Similarity in characteristics resulting from a shared ancestry. Indicates true evolutionary relationship from shared ancestry.

Flashcard 39: What is an ultrametric tree?

Answer: A tree where all paths from the root to the leaves are of equal length. Assumes molecular clock with constant evolutionary rates.

Flashcard 40: What is analogy in phylogeny?

Answer: Similarity due to convergent evolution, not common ancestry. Can mislead phylogenetic analysis by suggesting false relationships.

Flashcard 41: What is a basal taxon in a phylogenetic tree?

Answer: A lineage that diverges early in the history of a group. Represents an early-branching evolutionary lineage.

Flashcard 42: What is the importance of genetic distance in phylogeny?

Answer: It measures evolutionary divergence between species or sequences. Quantifies how much species have diverged evolutionarily.

Flashcard 43: What is the principle of parsimony in phylogenetics?

Answer: The simplest explanation or path with the least evolutionary changes is preferred. Minimizes assumptions about evolutionary change events.

Flashcard 44: What is a molecular marker in phylogenetics?

Answer: A specific DNA sequence used to study genetic relationships. Provides data points for comparing evolutionary divergence.

Flashcard 45: What is a paraphyletic group?

Answer: A group that includes an ancestor but not all of its descendants. Creates artificial groups that exclude some descendants.

Flashcard 46: What is the distinction between taxonomy and phylogeny?

Answer: Taxonomy classifies organisms; phylogeny studies their evolutionary relationships. Taxonomy groups organisms; phylogeny traces their evolution.

Flashcard 47: What is analogy in phylogeny?

Answer: Similarity due to convergent evolution, not common ancestry. Can mislead phylogenetic analysis by suggesting false relationships.

Flashcard 48: What is a sister group in phylogeny?

Answer: Two descendants that split from the same node in a phylogenetic tree. Share the most recent common ancestor with each other.

Flashcard 49: What is the importance of genetic distance in phylogeny?

Answer: It measures evolutionary divergence between species or sequences. Quantifies how much species have diverged evolutionarily.

Flashcard 50: What is a character matrix?

Answer: A table showing the presence or absence of traits across taxa. Organizes trait data for phylogenetic analysis.

Flashcard 51: What is an evolutionary tree?

Answer: A diagram that represents hypotheses about the history of species divergence. Shows branching patterns of species through time.

Flashcard 52: What is a polyphyletic group?

Answer: A group that does not include the most recent common ancestor of its members. Forms unnatural groups based on convergent evolution.

Flashcard 53: How is molecular clock used in phylogenetics?

Answer: It estimates time of evolutionary events based on mutation rates. Assumes constant mutation rates to calculate divergence times.

Flashcard 54: Identify a technique used to infer phylogenetic trees.

Answer: Maximum likelihood or Bayesian inference methods. Statistical methods that evaluate multiple possible trees.

Flashcard 55: What are paralogs?

Answer: Genes related by duplication within a genome. Result from gene duplication within the same organism.

Flashcard 56: What is phylogeny?

Answer: Phylogeny is the evolutionary history and relationship of an organism or group of organisms. Shows how species evolved and are related through time.

Flashcard 57: What does a branch point in a phylogenetic tree represent?

Answer: A branch point represents a common ancestor of the lineages that diverge from it. Also called a node; where lineages split in evolutionary time.

Flashcard 58: What is a polyphyletic group?

Answer: A group that does not include the most recent common ancestor of its members. Forms unnatural groups based on convergent evolution.

Flashcard 59: What are paralogs?

Answer: Genes related by duplication within a genome. Result from gene duplication within the same organism.

Flashcard 60: How does convergent evolution affect phylogenies?

Answer: It can lead to analogous traits that may mislead phylogenetic inference. Creates homoplasy that obscures true evolutionary relationships.

Flashcard 61: What is a phylogenetic tree?

Answer: A diagram that represents evolutionary relationships among organisms. Branch patterns show how species diverged from common ancestors.

Flashcard 62: What is phylogeny?

Answer: Phylogeny is the evolutionary history and relationship of an organism or group of organisms. Shows how species evolved and are related through time.

Flashcard 63: What is a sister group in phylogeny?

Answer: Two descendants that split from the same node in a phylogenetic tree. Share the most recent common ancestor with each other.

Flashcard 64: What is a consensus tree?

Answer: A tree that summarizes the common features of a set of trees. Shows areas of agreement among different phylogenetic analyses.

Flashcard 65: What are synapomorphies?

Answer: Shared derived characters used to construct phylogenetic trees. Define clades by showing evolutionary novelties.

Flashcard 66: What is the purpose of bootstrap analysis in phylogenetics?

Answer: To assess the reliability of inferred phylogenetic trees. Statistical resampling method to test tree robustness.

Flashcard 67: What is a basal taxon in a phylogenetic tree?

Answer: A lineage that diverges early in the history of a group. Represents an early-branching evolutionary lineage.

Flashcard 68: What is a reticulate evolution?

Answer: Evolution involving the merging of different lineages through hybridization. Creates network-like patterns rather than simple trees.

Flashcard 69: How does convergent evolution affect phylogenies?

Answer: It can lead to analogous traits that may mislead phylogenetic inference. Creates homoplasy that obscures true evolutionary relationships.

Flashcard 70: What is homology?

Answer: Similarity in characteristics resulting from a shared ancestry. Indicates true evolutionary relationship from shared ancestry.

Flashcard 71: Identify a technique used to infer phylogenetic trees.

Answer: Maximum likelihood or Bayesian inference methods. Statistical methods that evaluate multiple possible trees.

Flashcard 72: What is a character state?

Answer: A specific form or variation of a character (trait) in a species. Different expressions of the same trait across species.

Flashcard 73: What is a character state?

Answer: A specific form or variation of a character (trait) in a species. Different expressions of the same trait across species.

Flashcard 74: Identify the root of a phylogenetic tree.

Answer: The root represents the most recent common ancestor of all taxa in the tree. The starting point showing the oldest common ancestor.

Flashcard 75: Define 'node' in the context of a phylogenetic tree.

Answer: A point on a tree where a lineage splits into two or more lineages. Branch points where evolutionary splitting occurs.

Flashcard 76: Define the term 'phylogenetic signal'.

Answer: The pattern of trait resemblance among species due to shared ancestry. Strong signal indicates reliable phylogenetic inference.