Biology Chapter 12 Diversity of Life

A branching diagram that shows the evolutionary relationships among organisms.

The evolutionary history and relationships among a species or group of species.

The study of organisms in order to understand their relationships.

Archaea, Bacteria, and Eukarya; the broadest categories of life based on evolutionary relationships

The sequence of events that leads to the evolution of a species or group of species.

The shared ancestor from which all organisms in a group evolved.

The science of classifying and naming organisms.

Represent evolutionary relationships that diverge from common ancestry.

A branching diagram showing the evolutionary relationships among different species.

A hierarchical system for classifying organisms.

A system organized in levels, with each group containing smaller groups.

The broadest taxonomic category, encompassing Bacteria, Archaea, and Eukarya.

The unique, two-part name that gives the genus and species and that scientists use internationally.

A point on a phylogenetic tree where lineages diverge.

The development of new characteristics or adaptations over time in lineages.

Closely related species may not always look similar if they evolved in different environments.

In a phylogenetic tree, a branch length does NOT necessarily indicate the time elapsed.

A shelled egg that develops outside of water, enabling life on land.

A phylogenetic tree with a common ancestor at the base establishing the evolutionary relationships of organisms

The principle that the simplest explanation for evolutionary relationships is usually the best.

Similar traits in different organisms that are inherited from a common ancestor.

Scientists use parsimony to determine the order of evolutionary events by analyzing homologous traits and finding the simplest explanation.

DNA sequences provide insights into evolutionary relationships, sometimes uncovering unexpected connections.

The degree to which a species is unique in its evolutionary history, reflecting its genetic distinctiveness and the time it has been evolving on its own.

A method used to construct phylogenetic trees by grouping organisms into clades based on shared derived characteristics, indicating their evolutionary relationships.

A group of organisms that includes a common ancestor and all of its descendants, forming a single branch on a phylogenetic tree.

A group of organisms that includes a common ancestor and all of its descendants, forming a single clade.

Traits that have evolved in a lineage and are shared by all members of that lineage.

The diversity of evolutionary relationships among organisms, highlighting the importance of preserving unique evolutionary lineages.

The determination of which species or habitats require the most urgent protection based on factors like extinction risk and evolutionary distinctiveness.

A trait found in all members of a group because it hasn't changed during their descent. It's not useful for determining relationships within the group because everyone has it.

A trait that evolved at some point during the descent of a group, present only in some members. Helps determine relationships between those with the trait.

A principle in cladistics that states the simplest explanation for evolutionary relationships is usually the most accurate. Assuming an event happened in the most obvious way.

A particular form of a trait. For example, eye color is a character, and blue or brown are character states.

It suggests the trait evolved in the ancestor, but then changed back in that one species. An example of evolutionary reversal.

It likely evolved independently in those clades, a case of convergent evolution.

Building a cladogram is complex because there are many choices to make. There may be disagreements about which characters are most important, or how to interpret them.