Teeling L2: Genomics & Phylogenetic Trees

Phylogenetic tree

Hypothesis about evolutionary relationships among species.

Branch point

Where lineages diverge in a phylogenetic tree.

Sister taxa

Groups sharing an immediate common ancestor.

Rooted tree

Includes a branch for the last common ancestor.

Basal taxon

Diverges early near the common ancestor.

Polytomy

Branch from which more than two groups emerge.

Ancestral lineage

The common ancestor of all taxa in a tree.

Phylogeny

Study of evolutionary relationships among organisms.

Homology

Similarity due to shared ancestry between organisms.

Analogy

Similarity due to convergent evolution, not ancestry.

Homoplasies

Analogous structures or sequences evolved independently.

Convergent evolution

Similar adaptations from similar environmental pressures.

Phenotypic similarities

Similar physical traits indicating evolutionary relationships.

Genetic similarities

Similar DNA sequences suggesting close relatedness.

Systematists

Scientists who classify organisms based on phylogeny.

Shared derived characters

Traits shared by a group, derived from a common ancestor.

Fins and flippers

Example of homologous structures in different species.

Complexity in structures

More complex structures likely indicate homology.

Molecular sequences

DNA comparisons used to determine evolutionary relationships.

Environmental pressures

Factors influencing convergent evolution in different species.

Whale meat identification

Phylogeny used to trace whale species origins.

SARS-CoV-2 origin

Investigated using phylogenetic analysis of viruses.

Morphological similarity

Similar physical traits between species.

Molecular data

DNA sequences used for genetic analysis.

Homologous genes

Genes that share an evolutionary ancestor.

Orthologs

Homologous genes in different species.

Paralogs

Homologous genes within the same species.

Gene duplication

Process creating multiple copies of a gene.

Speciation

Formation of new species through evolution.

Ancestral gene

Original gene from which others are derived.

Shared derived characters

Traits inherited from a common ancestor.

Analogous structures

Similar traits not derived from a common ancestor.

Molecular homologies

Genetic similarities indicating evolutionary relationships.

Molecular homoplasies

Coincidental genetic similarities in unrelated species.

Functional genomics

Study of gene functions using genomic data.

Systematists

Scientists who classify and analyze species relationships.

Insertion and deletion

Changes in DNA sequences affecting gene length.

Evolutionary relationships

Connections between species based on ancestry.

Computer programs

Tools for analyzing DNA sequences.

Mathematical tools

Methods used to analyze genetic data.

Species estimate

Up to 8.7 million species may exist.

Divergence of gene

Evolutionary changes in gene sequences over time.

Evolutionary time

Duration over which species evolve.

Comparable DNA segments

DNA sequences used for comparative analysis.

Phylogenetic tree

Diagram depicting evolutionary relationships among species.

Homologous characters

Traits derived from a common ancestor.

Cladistics

Classification based on common descent.

Clade

Group including an ancestor and all descendants.

Monophyletic group

A clade consisting of an ancestor and all descendants.

Paraphyletic group

Ancestral species with some, but not all, descendants.

Polyphyletic group

Group with species from different ancestors.

Shared ancestral character

Trait originating in a common ancestor.

Shared derived character

Novel trait unique to a specific clade.

Ancestral character

Trait present in the ancestor of a taxon.

Derived character

Trait that evolved in a particular clade.

Evolutionary novelty

New trait that appears in a lineage.

Outgroup

Species used to compare and infer traits.

Character table

Matrix displaying traits across different taxa.

Vertebral column

Backbone distinguishing vertebrates from invertebrates.

Hinged jaws

Feature that evolved in some vertebrates.

Four walking legs

Characteristic of certain tetrapods.

Amnion

Membrane surrounding embryo in amniotes.

Hair

Unique trait distinguishing mammals from other vertebrates.

Branch point

Node in a phylogenetic tree indicating divergence.

Taxon

Group of one or more populations of organisms.

Evolutionary relationships

Connections based on shared ancestry and traits.

Outgroup

Species closely related to the ingroup studied.

Ingroup

Group of species being analyzed in a study.

Shared derived characteristics

Traits unique to a specific clade.

Shared ancestral characteristics

Traits present before divergence from a common ancestor.

Cladistic analysis

Method to study evolutionary relationships among species.

Lancelet

An outgroup species lacking a backbone.

Vertebral column

Backbone present in all ingroup vertebrates.

Hinged jaws

Feature present in most ingroup vertebrates.

Four walking legs

Characteristic of certain terrestrial vertebrates.

Maximum Parsimony

Principle minimizing the number of evolutionary changes.

Maximum Likelihood

Statistical method estimating tree likelihood based on data.

Convergent evolution

Independent evolution of similar traits in different species.

Reversal evolution

Return to an ancestral trait in a lineage.

Synapomorphy

Shared derived trait among a group of organisms.

Phylogenetic tree

Diagram representing evolutionary relationships among species.

Character table

Matrix showing traits of different taxa.

Paleontology

Study of ancient life through fossils.

Morphology

Study of the form and structure of organisms.

Gene sequences

DNA sequences used to determine evolutionary relationships.

Divergence

Process by which species evolve different traits.

Maximum Parsimony

Tree with fewest evolutionary events is favored.

Maximum Likelihood

Tree reflects most probable DNA change sequence.

Phylogenetic Hypotheses

Different tree structures representing evolutionary relationships.

Parsimony

Minimizing evolutionary changes in tree construction.

Computer Programs

Tools used to identify parsimonious trees.

Shared Derived Characters

Traits that appear in some species but not others.

Branch Length

Indicates number of genetic changes or time.

Phylogenetic Bracketing

Predicting features of ancestors from descendants.

Morphological Data

Physical traits used to construct phylogenetic trees.

Molecular Data

Genetic sequences analyzed for evolutionary relationships.

Fossil Record

Historical evidence supporting evolutionary hypotheses.

Ancestral Sequence

Original DNA sequence from which species diverged.

Evolutionary Events

Occurrences of changes in species over time.

Chronological Time

Time representation in branch lengths of trees.