Understanding Phylogenetic Trees

What is a phylogenetic tree?

• A diagram that represents evolutionary relationships among organisms

• A historical record of species extinction

• A type of plant found in tropical areas

• A mathematical formula used to calculate genetic mutations

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What does the pattern of branching in a phylogenetic tree reflect?

• The complexity of the organism

• The lifespan of each species

• How species evolved from a series of common ancestors

• The geographical distribution of species

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Can phylogenetic trees be drawn in different styles?

• Yes, and rotating a tree about its branch points doesn't change the information it carries

• No, there is only one correct way to draw a phylogenetic tree

• Yes, but each style represents different evolutionary information

• No, because it would alter the scientific data

What does it mean for two species to be more related in the context of phylogenetic trees?

• They are physically more similar to each other

• They share a more recent common ancestor

• They are found in the same geographical area

• They belong to the same genus

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Are phylogenetic trees only for species?

• No, they are used only for plants

• Yes, because only species have genetic data

• No, they can show relationships at various levels such as populations and subspecies

• Yes, they are exclusively used for species

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What is represented at each branch point in a phylogenetic tree?

• The time period during which the species lived

• The number of mutations that occurred

• The physical location where the species were found

• A divergence event or splitting apart of a single group into two descendant groups

How can we determine which species are more related?

• By measuring the physical size of the species

• By the color of the branches in the tree

• By tracing the lines of species backward in the tree to their convergence point

• By counting the number of leaves on the branches

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What does a polytomy in a phylogenetic tree indicate?

• That the tree is incorrectly drawn

• That the species involved are not related

• That there is definitive information about the evolutionary relationships

• That there is insufficient information to determine the branching order

What is the significance of rotating the branches in a phylogenetic tree?

• It helps to better visualize the data

• It is used to confuse predators

• It changes the evolutionary relationships depicted

• It has no impact on the relationships shown

What kind of data can be used to build a phylogenetic tree?

• Only fossil records

• Only behavioral patterns

• A variety of characteristics including morphology, DNA sequences, and behaviors

• Only DNA sequences

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