Evolution and Phylogeny: Key Concepts in Biological Classification

What is evolution?

A change (genetic) in a species from generation to generation.

Define species in the context of evolution.

A group of similar organisms able to potentially interbreed in nature and produce fertile offspring.

What is phylogeny?

The study of evolutionary relationships among species.

How do scientists determine evolutionary changes?

By looking for similarities and differences in fossils, geology, vestigial structures, biochemistry, embryology, homologous structures, and molecular biology.

What is a hypothesis in evolutionary biology?

A proposed explanation that is not an absolute fact but can have substantial support.

What does taxonomy refer to?

The classification of organisms into hierarchical levels, each called a taxon.

What is systematics?

The study of classification and the relationships among organisms.

What are sister taxa?

Two taxa that are more closely related to each other than to any other taxa.

What is a basal taxon?

A taxon that diverges early in the evolutionary history of a group.

What does a root indicate in a phylogenetic tree?

It indicates where a species is connected to its ancestors.

What is a polytomy?

An unresolved pattern of divergence in a phylogenetic tree.

What defines a monophyletic group (clade)?

A group connected by a common ancestor.

What is binomial nomenclature?

A two-part naming system for species, consisting of the genus and species name.

What are vestigial structures?

Remnants of features that served a function in the organism's ancestors.

What is the difference between homology and analogy?

Homology refers to similarities due to common ancestry, while analogy refers to similarities due to convergent evolution.

What is convergent evolution?

The independent evolution of similar features in different lineages.

What is natural selection?

A process of editing in populations that favors characteristics providing an advantage in a specific environment.

What is biogeography?

The study of the geographic distribution of species as evidence of evolution.

What is cladistics?

A classification method that uses common ancestry as the primary criterion.

What is a clade?

A group classification that includes an ancestral species and all of its descendants.

What is a shared ancestral character?

A character that originated in an ancestor of the taxon.

What is a shared derived character?

An evolutionary novelty unique to a particular clade.

What is molecular homology?

The study of similarities in genes and DNA sequences among different organisms.

What is the principle of parsimony in phylogenetics?

The idea that the simplest explanation, requiring the fewest changes, is preferred.

What are homoplasies?

Similar traits that arise independently, often due to convergent evolution.

What is the significance of molecular data in phylogenetic studies?

It helps track evolutionary relationships and shared characteristics among species.

What is the role of vestigial structures in understanding evolution?

They provide evidence of an organism's evolutionary history and past functions.