Hi. The question you presented above is incomplete. This makes it impossible for this question to be answered. However, when searching for your question on the internet, I was able to find another question exactly like yours, which asked you to explain the evolutionary relationship between these three species. If that's the case for you, I hope the answer below will help you.
In a simplified way, we can infer that among the three species presented above, the third presented a faster evolution than the first two and this is what explains the difference between the gene sequences between the species. As the question presents, the three species have related genes, which indicates that they had a common ancestor, however the difference in the gene sequence of the third species shows that it evolved first, showing changes that cannot be noticed in the first two species that are evolving more slowly.