19.2 Modern Evolutionary Classification Flashcards
(18 cards)
Phylogeny
Study of the evolutionary relationships among organisms
Clade
Evolutionary branch of a cladogram that includes a single ancestor and all its descendants—living and extinct
Cladogram
Diagram showing patterns of shared characteristics among species. It shows current hypotheses about how evolutionary lineages branched off from common ancestors
Derived character
Trait that arose in the most recent common ancestors and was passed down to its descendants
Cladistic analysis
Is a method used in modern evolutionary classification. It compares carefully selected traits to determine the order in which groups of organisms branched off from their common ancestors
What revolutionized classification?
The Darwinian concept of descent with modification
What suggests a way to classify organisms on how closely related they are?
Darwin’s tree of life
When taxa are aligned as in Darwin’s tree of life, what falls apart?
Some old Linnaean ranks fall apart
What gave birth to the field of phylogeny
The first Darwinian theory
Advances in phylogeny led to what?
Evolutionary classification
The goal of evolutionary classification
To group species into larger categories to reflect lines of evolutionary descent, rather than of similarities and differences
Classifying organisms according to lines of evolutionary descent place them into…
Clades
The relationship of lineages to each other is based on what?
It is based on how recent they shared a common ancestor. The more recent, the closer the relationship is.
In carnivora, what is a derived character?
Shearing teeth
Derived character for the entire clade of Mammalia
Hair
Derived character for the entire clade of Tetrapoda
Four limbs
Derived character for clade Felidae
Retractable claws
Goal of modern systematics
To understand the evolutionary relationships of all life on Earth
