Let’s think through this step by step.
The worksheet is asking you to predict which two organisms — horse, gorilla, or human — are most similar based on biochemical evidence (specifically, the amino acid sequence in hemoglobin).
We’re told:
- Similar DNA → similar proteins → similar amino acid sequences.
- The more similar the amino acid sequences, the more closely related the organisms are likely to be.
- Scientists use this to figure out evolutionary relationships.
Now, let’s think about what we know from biology (even if it’s not written here):
Humans and gorillas are both primates. They share a much more recent common ancestor with each other than either does with a horse. Horses are mammals too, but they’re in a completely different group (ungulates) and diverged from primates millions of years ago.
So, even without seeing the actual data yet, we can make an educated prediction:
→ Humans and gorillas should have more similar hemoglobin amino acid sequences than either has with horses.
Why? Because they’re more closely related evolutionarily. Their DNA is more alike, so their proteins (like hemoglobin) will also be more alike.
This matches what scientists actually found when they studied this — human and gorilla hemoglobin are very similar, while horse hemoglobin differs more.
Final Answer:
Gorilla and human are predicted to be most similar because they are more closely related evolutionarily, meaning their DNA and protein sequences (like hemoglobin) are more alike than those of either species compared to the horse.
Parent Tip: Review the logic above to help your child master the concept of biochemical evidence for evolution worksheet.
