Cladogram Worksheet | Study notes Microbiology | Docsity - Free Printable

Final Answer:
1. Table filled:
- Worm: cells ✔, legs ✘, 6 legs ✘, wings ✘
- Spider: cells ✔, legs ✔, 6 legs ✘ (has 8), wings ✘
- Carpenter Ant (black): cells ✔, legs ✔, 6 legs ✔, wings ✘ (workers lack wings; assume worker ant unless specified)
- Fly: cells ✔, legs ✔, 6 legs ✔, wings ✔

2. Cladogram order (from most ancient/common ancestor to most recent):
Worm → Spider → Ant → Fly

3. Reasons (complete sentences):
- I placed the worm first because it is the only one without legs or wings and belongs to a different phylum (Annelida), so it shares fewer traits with the others.
- I placed the spider next because it has legs but not 6 legs (it has 8) and no wings, and it’s an arachnid—more complex than a worm but less so than insects.
- I placed the ant third because it has 6 legs (like all insects) and no wings (assuming a worker ant), so it shares the “6 legs” trait with flies but lacks wings.
- I placed the fly last because it has 6 legs *and* wings, which are advanced traits shared only among some insects, making it the most derived of these four.

4. Traits to label on branches (from bottom to top):
- Branch after worm: “has legs”
- Branch after spider: “has 6 legs”
- Branch after ant: “has wings”

5. Worms and spiders are *less* closely related; worms and ants are *even less* related. Spiders and ants are more closely related to each other than either is to worms, because both spiders and ants have legs (unlike worms), and ants and flies (both insects) share 6 legs and other features. But between the pairs asked: spiders and ants are more closely related than worms and ants, because spiders and ants both have jointed legs and exoskeletons (arthropods), while worms do not. So: spiders and ants are more closely related. We know this because they share more recent common ancestry (both are arthropods), while worms are not arthropods.

6. Flies are most closely related to ants, because both are insects—they share key traits: 6 legs, body divided into head/thorax/abdomen, and (in reproductive forms) wings. Even though worker ants lack wings, the group (Hymenoptera) and flies (Diptera) are both in the class Insecta, sharing a more recent common ancestor than with spiders or worms.

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