phylogeny review worksheet answers Doc Template | pdfFiller - Free Printable

Problem Overview:

The task involves creating a phylogenetic tree worksheet by analyzing the traits of different organisms (worm, spider, carpenter ant, and fly) and using these traits to construct a cladogram. The goal is to determine evolutionary relationships based on shared characteristics.

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Step-by-Step Solution:

#### 1. Fill in the following table. Mark an "X" if an organism has the trait.

We need to analyze the traits for each organism: cells, legs, 6 legs, and wings.

| Organism | Cells | Legs | 6 Legs | Wings |
|--------------|-------|------|--------|-------|
| Worm | X | | | |
| Spider | X | X | | |
| Carpenter Ant| X | X | X | |
| Fly | X | X | X | X |

- Worm: Has cells but no legs, 6 legs, or wings.
- Spider: Has cells and legs but not 6 legs or wings.
- Carpenter Ant: Has cells, legs, and 6 legs but no wings.
- Fly: Has cells, legs, 6 legs, and wings.

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#### 2. Add each of these organisms to the cladogram below.

To construct the cladogram, we need to group organisms based on shared traits. Here’s how we can do it:

1. Worm: It lacks legs, so it will be placed separately as the most basal (primitive) organism.
2. Spider: It has legs but not 6 legs or wings. It will be grouped with other legged organisms but separated from those with 6 legs.
3. Carpenter Ant: It has legs and 6 legs but no wings. It will be grouped with the fly because both have 6 legs.
4. Fly: It has legs, 6 legs, and wings. It will be grouped with the carpenter ant due to the 6 legs trait but will branch off due to the presence of wings.

The cladogram will look like this:

```
[Worm]
|
|
[Spider]-----[Legs]------------------[6 Legs]
|
|
[Carpenter Ant]---[Wings]---[Fly]
```

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#### 3. Using complete sentences, explain why you put each organism where you did on the cladogram.

- Worm: The worm was placed at the base of the cladogram because it lacks legs, which is a key trait shared by the other organisms. This indicates that it diverged early in evolution.
- Spider: The spider was grouped with other organisms that have legs but not 6 legs or wings. This suggests that the acquisition of legs occurred before the divergence of spiders from other arthropods.
- Carpenter Ant: The carpenter ant was grouped with the fly because both have 6 legs, indicating a more recent common ancestor compared to the spider.
- Fly: The fly was placed as a descendant of the 6-legged group but branched off due to the presence of wings, a derived trait.

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#### 4. On the cladogram above, add traits that make the organisms different from each other.

The cladogram should include the following traits as branching points:
- Legs: Separates worms from other organisms.
- 6 Legs: Separates spiders from ants and flies.
- Wings: Separates ants from flies.

Updated cladogram:
```
[Worm]
|
|
[Spider]-----[Legs]------------------[6 Legs]
|
|
[Carpenter Ant]---[Wings]---[Fly]
```

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#### 5. According to your cladogram, which two species are more closely related—worms and spiders or spiders and ants? How do you know?

- Spiders and ants are more closely related than worms and spiders.
- Reason: Spiders and ants share the trait of having legs, which places them in the same clade. Worms lack legs and are placed in a separate clade, indicating a more distant relationship.

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#### 6. According to your cladogram, what species are flies most closely related to? How do you know?

- Flies are most closely related to carpenter ants.
- Reason: Both flies and carpenter ants have 6 legs, which is a shared derived trait. Flies further diverge due to the presence of wings, but they still belong to the same clade as carpenter ants based on the 6-legs trait.

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#### 7. Fill in the following table. Mark an "X" if an organism has the trait.

We need to analyze the traits for hair, legs, no tail, and eyes.

| Organism | Hair | Legs | No Tail | Eyes |
|--------------|------|------|---------|------|
| Worm | | | X | |
| Spider | | X | X | X |
| Carpenter Ant| X | X | X | X |
| Fly | | X | X | X |

- Worm: No hair, no legs, no tail, no eyes.
- Spider: No hair, has legs, no tail, has eyes.
- Carpenter Ant: Has hair, has legs, no tail, has eyes.
- Fly: No hair, has legs, no tail, has eyes.

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Final Answer:

1. Table filled as shown above.
2. Cladogram constructed as explained.
3. Explanation provided for each placement.
4. Traits added to the cladogram.
5. Spiders and ants are more closely related.
6. Flies are most closely related to carpenter ants.
7. Table filled as shown above.

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