Building Phylogenetic Trees
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Objective
I can construct a phylogenetic tree to represent evolutionary relationships.
Part 1 of 4
Warm-up video
Khan Academy · 10:56Vetted channel
We don't generate video — this one is by Khan Academy on YouTube. The practice questions and exit ticket below were drafted by AI for this objective, and every question is editable in the teacher guide.
Part 2 of 4
Key concepts
3 concepts
- 1
A phylogenetic tree shows how different species evolved from common ancestors based on observable traits and molecular evidence.
- 2
The outgroup, like the lamprey in this example, is the species that is most different and whose common ancestor is most distant in the past.
- 3
When constructing a phylogenetic tree, biologists use parsimony to find the simplest explanation for the observed traits and relationships among species.
Part 3 of 4
Practice
12 questions
What is the primary goal of constructing a phylogenetic tree?
In the context of phylogenetic trees, what does 'parsimony' refer to?
Part 4 of 4
Exit ticket
Quick comprehension check
“Using the traits of jaws, lungs, fur, and feathers, construct a simple phylogenetic tree showing the evolutionary relationships between a lamprey, sea bass, antelope, and bald eagle. Clearly indicate the outgroup and where each trait evolved on the tree.”
Sample answer included in the free materials
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