Pets

they might be related. A group of ferals who hang around together might be intermating so that some of them become related. Kind of like people in small villages in the past, before the ability to travel long distances easily. Eventually the village members became related.

But, on the other hand, some coat patterns in cats are common enough that they show up in cats that are not related, like tabby and white, tabby with no white, cats with heart shapes in their fur, spots, broken stripes. So unrelated cats can look similar.