they were intended as a sort of note a person would write to him or herself as a reminder.
because our languages share some common origins...
Well, a piccolo is similar to the flute because is the same but piccolo is a bit smaller and also recorder and all the other woodwind (and metal wind) instruments are related to the flute because it is in the same family!
Because they are evolutionarily related - they both had a common ancestor. They have similar body shapes and similar social behaviours.
how are the origins of rock salt and some limestone similar
The structure of a memoir is similar to the structure of a narrative.
Spanish and French words both have Latin origins, which is why a lot of their words are similar. So there may be a few Spanish words with french origins, but very few.
I think they are similar because a triangle can fit into a circle and vise versa.
ancestor
Hydrogen and oxygen are similar because we both need them to survive hehehe
Homologous structures are similar structures that related species inherit from a common ancestor. These structures may have different functions in different species but share a similar underlying anatomy, suggesting shared evolutionary origins. Examples include the wing of a bird and the flipper of a whale, both being modified versions of the forelimb structure shared by their common ancestor.
There are Hindu gods and demons in Buddhist art because both the philosophy and the religion have very similar origins.
because the things in space are very weird looking. and the they are similar because the things in space have one more of everything. they are different because they are different shapes and sizes.