Tree Structure & Terms
This is the study of evolutionary relationships among species based on the idea that all life has a common ancestor.
Phylogeny
This famous scientist made the first sketch of an evolutionary "tree" in 1837
Charles Darwin
Scientists use this universal molecule to compare base sequences and determine how closely related different organisms are.
DNA
On a phylogenetic tree, these two taxa (A and B) are considered the most closely related because they share a recent common ancestor at a specific node.
Sister Groups
These nodes represent the actual units under comparison at the end of a lineage.
Terminal Nodes
This term refers to any group of organisms (like a species or family) placed at the tips of a tree.
Taxon
These are pairs of taxa that are more closely related to each other than to any other group because they share a recent common ancestor.
Sister Groups
This hypothetical organism lived about 1.5 billion years ago and is the ancestor of all life on Earth.
LUCA
$100: While some diagrams go from left to right, a cladogram can also be drawn in this direction.
Vertical
In technical terms, Terminal Nodes are known by this three-letter abbreviation.
OTU
These nodes, also called OTUs, represent the specific units or species being compared at the very ends of the branches.
Terminal Nodes
These are unrooted trees that show how related taxa are but do not provide an evolutionary path or time.
Phenograms
These are the building blocks of proteins (there are 22 types) that scientists compare to find evolutionary links.
Amino Acids
This is another name for the "tips" of the tree branches where the names of the organisms are written.
Leaves
These nodes represent hypothetical ancestral units where branches meet
Internal Nodes
These represent ancestral units or "speciation events" where a single lineage splits into two.
Internal Nodes
Also known as phylograms, these cladograms have varying branch lengths to show evolutionary change.
Additive Trees
These genes control the placement and development of body parts; mutations in them can cause legs to grow where antennae should be!
Hox Genes
This specific type of tree is also known as a metric tree or a phylogram
Additive Tree
Internal Nodes are technically known by this three-letter abbreviation.
HTU
This is a group of organisms that includes a single common ancestor and all of its descendants.
Clade
This is a group of organisms used as a reference point that is less related to the main group being studied.
Outgroup
This specific 183-nucleotide DNA sequence is found in all Hox genes and provides strong evidence for common ancestry.
Homeobox
This general term refers to tree-like diagrams, specifically used when describing Ultrametric trees.
Dendrogram
This is the specific number of amino acids found in the "homeodomain" protein sequence of Hox genes.
61