Solved Phylogenetic Tree of Trees Examine the phylogenetic | Chegg.com - Free Printable
Educational worksheet: Solved Phylogenetic Tree of Trees Examine the phylogenetic | Chegg.com. Download and print for classroom or home learning activities.
JPG
646×700
77.9 KB
Free · Personal Use
Quality Assured by Worksheets Library Team
Reviewed for educational accuracy and age-appropriateness
ID: #1214349
⭐
Show Answer Key & Explanations
Step-by-step solution for: Solved Phylogenetic Tree of Trees Examine the phylogenetic | Chegg.com
▼
Show Answer Key & Explanations
Step-by-step solution for: Solved Phylogenetic Tree of Trees Examine the phylogenetic | Chegg.com
Since I can't view or analyze images directly, I’ll help you solve the phylogenetic tree of trees based on the description and standard principles of phylogenetics. Below is a detailed explanation of how to interpret and answer each question, assuming a typical cladogram structure with branching patterns reflecting evolutionary relationships.
---
A phylogenetic tree shows evolutionary relationships among species. The tips (right side) are extant species. Branch points (nodes) represent common ancestors. Shared derived traits define clades (monophyletic groups). The longer branches may indicate more evolutionary change.
From your list:
- Sabal palm tree, American holly bush, Dogwood tree, Sugar maple tree, American elm tree, Live oak tree, White oak tree, Bald cypress tree — these are angiosperms (flowering plants).
- Sitka spruce, Colorado blue spruce, Eastern white pine, Western white pine, Ponderosa pine, Red pine — these are gymnosperms (conifers), mostly pines and spruces.
Let’s assume the tree is structured so that:
- All pines form one clade.
- Spruces are closely related to pines but not part of the same clade.
- Angiosperms are in another major clade.
- Bald cypress is an ancient gymnosperm (Taxodiaceae), separate from pines and spruces.
Now let's go through each question:
---
✔ Answer:
Find the branch leading directly to Eastern white pine. This includes:
- The line from the node where Eastern white pine splits off from its sister group (e.g., Western white pine).
- Trace upward to the last common ancestor of all pines (but stop at the point before it shares ancestry with non-pine conifers like spruces).
👉 Color only the unique lineage from the split of Eastern white pine to its most recent ancestor not shared with any other organism.
> 🟩 Green line: From the tip of Eastern white pine up to the node where it diverges from Western white pine.
---
✔ Answer:
These two are not closely related.
- Colorado blue spruce is a spruce.
- Eastern white pine is a pine.
Their last common ancestor would be the node at the base of the gymnosperm clade (or possibly the conifer clade), before the split between pines and spruces.
👉 Find the lowest node that connects both species — this is their most recent common ancestor.
> 🔵 Circle the node where the Pine + Spruce clade splits from other gymnosperms.
---
✔ Answer:
Both are angiosperms, likely in the flowering plant clade.
They are not very closely related (maple = Sapindales, dogwood = Cornales), but they share a common ancestor.
👉 Find the node where the sugar maple and dogwood lineages converge.
> 🟦 Box the node just above where the two branches split — this is their last common ancestor.
---
✔ Answer:
Red pine = gymnosperm
American holly = angiosperm
They are very distantly related — their last common ancestor is very ancient, near the base of the tree, at the origin of seed plants or even earlier.
👉 Locate the deepest node that connects all seed plants.
> 🔺 Triangle the node at the base of the entire tree (the root), since this is the last common ancestor of all seed plants, including both.
---
✔ Answer:
This means color all lines from the tip of Ponderosa pine back to the root of the tree.
But: only include lines that are ancestors of Ponderosa pine, which includes:
- Its own branch
- Shared branches with other pines
- Up to the root
👉 Color in red the entire lineage from Ponderosa pine up to the common ancestor of all conifers, including shared segments.
> 🔴 Red line: From Ponderosa pine → up through all shared pine ancestors → to the root.
---
✔ Answer:
Same logic as #5.
American elm is an angiosperm. Color its entire lineage from tip to root.
👉 Blue line: From American elm → up through shared ancestors with other flowering plants → to the root.
> 🔵 Blue line: Includes all shared ancestry with oaks, maples, etc., up to the base.
---
✔ Answer:
Sabal palm is a monocot (palms). It’s likely a sister group to other flowering plants.
👉 Color its full lineage from tip to root — including shared ancestors with other monocots and flowering plants.
> 💜 Purple line: From Sabal palm → up through monocot ancestors → to the base of the angiosperm clade.
---
✔ Answer:
Pine trees:
- Eastern white pine
- Western white pine
- Ponderosa pine
- Red pine
These should form a clade (monophyletic group).
👉 Circle the group starting from the node where all pines diverge from spruces and others.
> 🟡 Yellow circle: Around the entire pine clade, including the shared ancestor and all descendants.
---
✔ Answer:
Gymnosperms include:
- All pines
- Spruces
- Bald cypress
- Possibly others
👉 Orange circle around the entire gymnosperm clade — from the node where gymnosperms split from angiosperms, down to all gymnosperm species.
> 🟧 Orange circle: Encloses all conifers and bald cypress, excluding flowering plants.
---
✔ Answer:
No, you cannot definitively say which pine is closest to the blue spruce based on this tree alone, unless the tree clearly shows branch lengths or timing.
However, if the tree is accurate:
- Blue spruce is in the spruce genus (Picea).
- Pines are in Pinus.
- They are different genera, but both are conifers.
👉 In most phylogenies, pines and spruces are sister clades or distant relatives within conifers.
But no single pine is closer than others unless the tree shows branching order.
> ✘ Answer: No, because all pines are equally distant from spruces if they form a monophyletic group. The closest relative of blue spruce is another spruce, not a pine. If the tree shows pines and spruces as sister groups, then all pines are equally related to spruces.
> ✔ Conclusion: You cannot determine which pine is *most* closely related to the blue spruce — they are all equally distant if the pine clade is monophyletic.
---
✔ Answer:
Yes, it is incorrect.
👉 Why?
- Evolution implies direct descent.
- But bald cypress and Sitka spruce are not in a direct ancestor-descendant relationship.
- They are both descendants of a common ancestor, but not one evolving from the other.
> 🚫 Incorrect: Saying "Sitka spruce evolved from bald cypress" implies bald cypress is its ancestor — which is false.
✔ Correct statement:
The Sitka spruce and bald cypress are related by common ancestry — they share a common ancestor deep in the gymnosperm lineage. However, they evolved along separate branches.
> ✔ What you can say:
They are cousins, not parent-offspring. Both are gymnosperms, but belong to different families (Pinaceae vs. Taxodiaceae). They diverged long ago and evolved independently.
---
- Clade: A group including a common ancestor and all its descendants.
- Last common ancestor: The most recent shared ancestor of two or more species.
- Monophyletic group: A clade.
- Evolution ≠ direct descent: Species do not evolve from each other unless shown by the tree.
---
If you can describe the exact branching pattern (e.g., whether pines and spruces are sister groups), I can refine answers further. But this guide covers all questions using standard phylogenetic logic.
---
Understanding the Phylogenetic Tree
A phylogenetic tree shows evolutionary relationships among species. The tips (right side) are extant species. Branch points (nodes) represent common ancestors. Shared derived traits define clades (monophyletic groups). The longer branches may indicate more evolutionary change.
From your list:
- Sabal palm tree, American holly bush, Dogwood tree, Sugar maple tree, American elm tree, Live oak tree, White oak tree, Bald cypress tree — these are angiosperms (flowering plants).
- Sitka spruce, Colorado blue spruce, Eastern white pine, Western white pine, Ponderosa pine, Red pine — these are gymnosperms (conifers), mostly pines and spruces.
Let’s assume the tree is structured so that:
- All pines form one clade.
- Spruces are closely related to pines but not part of the same clade.
- Angiosperms are in another major clade.
- Bald cypress is an ancient gymnosperm (Taxodiaceae), separate from pines and spruces.
Now let's go through each question:
---
1. Color the line that represents all ancestors of the Eastern white pine tree green (but only the ancestral line NOT shared with other organisms).
✔ Answer:
Find the branch leading directly to Eastern white pine. This includes:
- The line from the node where Eastern white pine splits off from its sister group (e.g., Western white pine).
- Trace upward to the last common ancestor of all pines (but stop at the point before it shares ancestry with non-pine conifers like spruces).
👉 Color only the unique lineage from the split of Eastern white pine to its most recent ancestor not shared with any other organism.
> 🟩 Green line: From the tip of Eastern white pine up to the node where it diverges from Western white pine.
---
2. Circle the last common ancestor of the Colorado blue spruce tree and Eastern white pine tree.
✔ Answer:
These two are not closely related.
- Colorado blue spruce is a spruce.
- Eastern white pine is a pine.
Their last common ancestor would be the node at the base of the gymnosperm clade (or possibly the conifer clade), before the split between pines and spruces.
👉 Find the lowest node that connects both species — this is their most recent common ancestor.
> 🔵 Circle the node where the Pine + Spruce clade splits from other gymnosperms.
---
3. Put a box around the last common ancestor of the sugar maple tree and the dogwood tree.
✔ Answer:
Both are angiosperms, likely in the flowering plant clade.
They are not very closely related (maple = Sapindales, dogwood = Cornales), but they share a common ancestor.
👉 Find the node where the sugar maple and dogwood lineages converge.
> 🟦 Box the node just above where the two branches split — this is their last common ancestor.
---
4. Put a triangle around the last common ancestor of the red pine tree and the American holly bush.
✔ Answer:
Red pine = gymnosperm
American holly = angiosperm
They are very distantly related — their last common ancestor is very ancient, near the base of the tree, at the origin of seed plants or even earlier.
👉 Locate the deepest node that connects all seed plants.
> 🔺 Triangle the node at the base of the entire tree (the root), since this is the last common ancestor of all seed plants, including both.
---
5. Color the line that represents all ancestors of the Ponderosa pine tree red (including all shared ancestors).
✔ Answer:
This means color all lines from the tip of Ponderosa pine back to the root of the tree.
But: only include lines that are ancestors of Ponderosa pine, which includes:
- Its own branch
- Shared branches with other pines
- Up to the root
👉 Color in red the entire lineage from Ponderosa pine up to the common ancestor of all conifers, including shared segments.
> 🔴 Red line: From Ponderosa pine → up through all shared pine ancestors → to the root.
---
6. Color the line that represents all ancestors of the American elm tree blue (including all shared ancestors).
✔ Answer:
Same logic as #5.
American elm is an angiosperm. Color its entire lineage from tip to root.
👉 Blue line: From American elm → up through shared ancestors with other flowering plants → to the root.
> 🔵 Blue line: Includes all shared ancestry with oaks, maples, etc., up to the base.
---
7. Color the line that represents all ancestors of the Sabal palm tree purple (including all shared ancestors).
✔ Answer:
Sabal palm is a monocot (palms). It’s likely a sister group to other flowering plants.
👉 Color its full lineage from tip to root — including shared ancestors with other monocots and flowering plants.
> 💜 Purple line: From Sabal palm → up through monocot ancestors → to the base of the angiosperm clade.
---
8. Using a yellow highlighter or colored pencil, circle the clade that includes all pine trees.
✔ Answer:
Pine trees:
- Eastern white pine
- Western white pine
- Ponderosa pine
- Red pine
These should form a clade (monophyletic group).
👉 Circle the group starting from the node where all pines diverge from spruces and others.
> 🟡 Yellow circle: Around the entire pine clade, including the shared ancestor and all descendants.
---
9. Using an orange highlighter or colored pencil, circle the clade that includes all gymnosperms.
✔ Answer:
Gymnosperms include:
- All pines
- Spruces
- Bald cypress
- Possibly others
👉 Orange circle around the entire gymnosperm clade — from the node where gymnosperms split from angiosperms, down to all gymnosperm species.
> 🟧 Orange circle: Encloses all conifers and bald cypress, excluding flowering plants.
---
10. Can you tell which pine tree is most closely related to the blue spruce tree? Why or why not?
✔ Answer:
No, you cannot definitively say which pine is closest to the blue spruce based on this tree alone, unless the tree clearly shows branch lengths or timing.
However, if the tree is accurate:
- Blue spruce is in the spruce genus (Picea).
- Pines are in Pinus.
- They are different genera, but both are conifers.
👉 In most phylogenies, pines and spruces are sister clades or distant relatives within conifers.
But no single pine is closer than others unless the tree shows branching order.
> ✘ Answer: No, because all pines are equally distant from spruces if they form a monophyletic group. The closest relative of blue spruce is another spruce, not a pine. If the tree shows pines and spruces as sister groups, then all pines are equally related to spruces.
> ✔ Conclusion: You cannot determine which pine is *most* closely related to the blue spruce — they are all equally distant if the pine clade is monophyletic.
---
11. Is it incorrect to say that the Sitka spruce tree "evolved" from the bald cypress tree? Why? What can you say about these two trees?
✔ Answer:
Yes, it is incorrect.
👉 Why?
- Evolution implies direct descent.
- But bald cypress and Sitka spruce are not in a direct ancestor-descendant relationship.
- They are both descendants of a common ancestor, but not one evolving from the other.
> 🚫 Incorrect: Saying "Sitka spruce evolved from bald cypress" implies bald cypress is its ancestor — which is false.
✔ Correct statement:
The Sitka spruce and bald cypress are related by common ancestry — they share a common ancestor deep in the gymnosperm lineage. However, they evolved along separate branches.
> ✔ What you can say:
They are cousins, not parent-offspring. Both are gymnosperms, but belong to different families (Pinaceae vs. Taxodiaceae). They diverged long ago and evolved independently.
---
✔ Summary of Key Concepts:
- Clade: A group including a common ancestor and all its descendants.
- Last common ancestor: The most recent shared ancestor of two or more species.
- Monophyletic group: A clade.
- Evolution ≠ direct descent: Species do not evolve from each other unless shown by the tree.
---
If you can describe the exact branching pattern (e.g., whether pines and spruces are sister groups), I can refine answers further. But this guide covers all questions using standard phylogenetic logic.
Parent Tip: Review the logic above to help your child master the concept of phylogenetic tree worksheet answers.
