Chapter 26 - Animal Phylogeny Flashcards
(26 cards)
Define phylogeny
The evolutionary history of a species or group of species
Define taxa (aka taxon)
Textbook def. - The named group at any level of the hierarchy
Simple - groups used to classify living things (think like folders)
Define sister taxa
Textbook def. - groups of organisms that share an immediate common ancestor that is not shared by any other group
They’re each other’s closest relatives
Define Homology
Similar traits in different species because they share a common ancestor (example: human arm and bat wing bones)
Define monophyly
A group that indicates an ancestor and all of its descendants (a true branch of the evolutionary tree)
Define paraphyly
A group that includes a common ancestor and some but not all of its descendants
Define binomial nomenclature
The 2-name system used to name species ( like Homo sapiens for humans)
Define analogy
Similar traits in different species not because of shared ancestry, but because of similar environments or functions (like bird wings and insect wings)
Define polyphyly
A group made up of species that do not share a common ancestor - they’re grouped based on similar traits, not family history
Define diversity
The variety of living things in the world or in a specific area
Define classification
Sorting and naming organisms based on shared characteristics
Define phylogenetic tree
A diagram that shows how species are related and have evolved over time
Define evolution
The process through which species change over time, usually through natural selection and genetic changes
Define relationships
Connections between species that show how closely or distantly they’re related
Define molecular homologies
Similar DNA or protein sequences in different species that suggest a shared ancestor
Define convergence
When different species evolve similar traits independently (not from a common ancestor)
What are snared ancestral characters?
Traits that were present in a distant ancestor and still exist in some of its descendants
What are shared derived characters?
New traits that appeared in a recent ancestor and are shared by its descendants
What are analogous structures?
Body parts that look or work the same but evolved separately (example: dolphin fins and fish fins)
What are homologous structures?
Body parts that come from a common ancestor, even it they now do different things example: cat paw and human hand).
Define clade
A group of organisms that includes a common ancestor and all of its descendants (basically a monophyletic group)
Define species
A group of organisms that can breed and produce fertile offspring
Define node
A point on a phylogenetic tree where one species splits into two (shows a common ancestor)
Define systematics
The science of naming, classifying, and figuring out evolutionary relationships among organisms
