Reconstructing trees: Parsimony - Understanding Evolution
This principle was implicit in the tree-building process we went through earlier with the vertebrate phylogeny. However, in most cases, the data are more complex than those used in our example and may point to several different phylogenetic hypotheses. In those cases, the parsimony principle can help us choose between them.
Credits - Understanding Evolution
The original UCMP phylogenetic systematics content was written by Allen Collins in 1994. The current version (2006) is by Anna Thanukos, with updates added by Isaac Krone (2020). Web production and graphics:
Using trees to make predictions about poorly-studied species: A …
→ Phylogenetic systematics. → Using trees. → Using trees to make predictions about poorly-studied species: A new drug. Using trees to make predictions about poorly-studied species: A new drug. Phylogenies also allow us to generate expectations about the characteristics of living organisms that we have not yet studied. For example ...
Understanding phylogenies
When a lineage splits (speciation), it is represented as branching on a phylogeny. When a speciation event occurs, a single ancestral lineage gives rise to two or more daughter lineages. Phylogenies trace patterns of shared ancestry between lineages.
Lessons and Resources - Understanding Evolution
Students build a phylogenetic tree from pipe cleaners that allows them to rotate branches, compare topologies, map complete lineages, identify informative phylogenetic features, and examine the effects of superficial structural changes on the tree.
Understanding Evolution
Understanding Evolution
Teaching the Process of Molecular Phylogeny and Systematics: A …
The inquiry-based student activity described herein is a novel approach toward the instruction of the practice of molecular phylogeny and systematics. The activities are appropriate for introductory biology curriculum, for nonmajors, and even secondary education levels.
Clades within clades - Understanding Evolution
A clade (also known as a monophyletic group) is a group of organisms that includes a single ancestor and all of its descendents. Clades represent unbroken lines of evolutionary descent. It’s easy to identify a clade using a phylogenetic tree. Just imagine clipping any single branch off the tree. All the lineages on that branch form a clade.
Homologies and analogies - Understanding Evolution
Since a phylogenetic tree is a hypothesis about evolutionary relationships, we want to use characters that are reliable indicators of common ancestry to build that tree. We use homologous characters — characters in different organisms that are similar because they were inherited from a common ancestor that also had that character.
UC Museum of Paleontology - Understanding Evolution
Learn about phylogenetic systematics, the study of the evolutionary relationships among organisms, and how the field is shaping biological research today. View details »
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