Phylogeny and the Tree of Life

These flashcards cover key terms and concepts related to phylogeny and the Tree of Life, aiding students in reviewing foundational ideas in evolutionary biology.

Phylogeny

The study of evolutionary relationships among biological entities.

Tree of Life

A metaphor for the relationships between all living organisms, often represented as a branching tree.

Homology

Similarity due to shared ancestry.

Analogy

Similarity due to convergent evolution.

Cladistics

A method of classification based on evolutionary ancestry.

Clade

A group consisting of an ancestor and all its descendants.

Monophyletic

A group that includes an ancestor and all its descendants.

Polyphyletic

A group that includes organisms from multiple ancestors without a common ancestor.

Paraphyletic

A group that includes an ancestor but not all of its descendants.

Shared Ancestral Characters

Features that originated in a distant ancestor of the taxon.

Shared Derived Characters

New traits that are unique to a clade and not found in ancestral species.

Outgroup

A lineage that diverged earlier and helps in identifying ancestral traits.

Branch Length

In phylogenetic trees, it can represent the amount of genetic change.

Maximum Parsimony

A principle that favors the simplest explanation consistent with the facts.

Derived Characters

Traits that evolve from more ancestral forms.

Phylogenetic Tree

A diagram that represents evolutionary relationships as hypotheses.

Evolutionary Novelties

Unique characteristics that arise within a clade.

Testable Scientific Hypotheses

Hypotheses that can be confirmed or refuted through observation or experiment.

Convergent Evolution

Independent evolution of similar traits in different lineages.

Monophyletic Group

Also known as a clade; it includes a common ancestor and all its descendants.

Crocodilians

A group of reptiles that includes crocodiles and alligators.

Theropod Dinosaurs

A group of dinosaurs that includes modern birds.

Evolutionary Relationships

Connections and lineage between species due to shared ancestry.

Taxon

Any group of organisms that is treated as a unit.

Character State

A specific condition of a character (for example, fur color).

Phylogenetic Hypothesis

A proposed explanation of the evolutionary relationships among organisms.

DNA Data

Genetic information used to infer evolutionary relationships.

Branching Pattern

The arrangement of branches in a phylogenetic tree.

Fossil Evidence

Remains or traces of past life used to infer evolutionary history.

Linnaean System

A hierarchical system for classifying organisms based on shared characteristics.

Incubation Behavior

Care behaviors exhibited by laying organisms, including birds and reptiles.

Extinct Species

Species that no longer exist.

Nested Hierarchies

Organization of groups within groups, characteristic of clades.

Species

A group of organisms that can interbreed and produce fertile offspring.

Evolution

Change in the heritable traits of biological populations over successive generations.

Common Ancestor

An ancestral species shared by multiple descendant species.

Genetic Changes

Changes in the DNA sequence that can lead to differing traits.

Character Evolution

The process by which new characteristics arise in species.

Clades

Groups of organisms that contain an ancestor and all of its descendants.

Taxonomic Classification

The process of organizing biological diversity into hierarchical groups.

Adaptive Radiation

The rapid evolution of diversely adapted species from a common ancestor.

Mammals

A group of warm-blooded vertebrates characterized by hair and milk-producing glands.

Hypothesis Testing

The process of making predictions and then determining their validity.

Biological Classification

The categorization of organisms based on shared traits.

Systematics

The scientific study of the diversity and relationships among organisms.

Ancestral Traits

Traits inherited from distant ancestors.

Derived Traits

Traits that have evolved in a lineage after diverging from their ancestors.

Evolutionary Tree

A diagram that depicts the evolutionary relationships between various species.

Molecular Phylogenetics

The use of molecular data to infer evolutionary relationships.

Geological Time Scale

A timeline of Earth's history, divided into eons, eras, periods, and epochs.

Common Features

Characteristics shared between different organisms due to common ancestry.

Sister Groups

Two groups that share a most recent common ancestor.

Fossil Record

The history of life documented by fossils.

Biodiversity

The variety of life in the world or a particular habitat.

Conservation Biology

The study of nature and biodiversity with the aim to protect species.

Ends of Branches

Parts of a phylogenetic tree where living species or lineages are represented.

Synapomorphy

A shared derived character that defines a clade.

Taxon Levels

Different ranks in the classification system, such as kingdom, phylum, class.

Ecosystem Function

The essential processes that occur within an ecosystem.

Molecular Clocks

A method used to date evolutionary events based on DNA mutations.

Heritable Characteristics

Traits that can be passed down from one generation to the next.

Phylogenetic Signals

Patterns in data that reflect evolutionary history.

Evolutionary History

The historical development and changes in species over time.

Transitional Fossils

Fossils that show intermediate traits between two groups.

Ecological Niches

The role or function of an organism within its environment.

Species Delimitation

The process of defining the boundaries of species.

Natural Selection

The process by which organisms better adapted to their environment tend to survive.

Ingroup

The group of species under study in phylogenetic analysis.

Gene Flow

The transfer of genetic material between populations.

Morphological Characters

Physical traits used to infer relationships between organisms.

Taxonomic Hierarchy

The organization of biological classification into ranks.

Paleontology

The study of the history of life on Earth through fossils.

Phylogenetic Analysis

The examination of evolutionary relationships to create trees.

Evolutionary Biologists

Scientists who study the processes of evolution.

Adaptations

Traits that enhance an organism's ability to survive and reproduce.

Organismic Diversity

The variety of different living organisms within an area.

Speciation Events

Occurrences where new species arise from existing populations.

Phylogenetic Methodologies

Techniques used to infer phylogenetic trees and evolutionary relationships.

Shared Traits

Characteristics that are common to two or more species.

Predictive Models

Frameworks to predict features of organisms based on phylogenetic relationships.

Species Relationships

Connections and differences between species based on shared traits.

Genetic Similarities

Similarities in DNA or genetic makeup among organisms.

Functional Traits

Characteristics that affect an organism’s function in an ecosystem.

Evolutionary Theory

A set of ideas explaining how evolution occurs.

Environmental Changes

Alterations in habitat that can impact species evolution.