Just like living things, language evolves - and sometimes in the same way. When a population splits into two isolated groups, both evolve differently. *
In the 11th century, the modern French word guerre was pronounced gwerra. When the word arrived in England (courtesy of the Norman invaders after 1066), it was effectively isolated from the original language 'population' among British speakers who learnt French. The word mutated and lost the G so we pronounced it, after a few more mutations, as war. Roughly: gwerra to werre to war. Dropping the E on the end of the word is a common mutation.
Mediaeval scribes often used signs as shortcuts. In the 11th century, the word for school was written and pronounced escole (compare with escuela in Spanish, also a Romance language - which means derived from Latin). Later, it was written with an accent at the start as a scribes' sign that there was an S after the E . It's now written école and the S has been dropped from pronunciation. But before that happened, it came over here as escole, from which we got school.
The circumflex was a scribes' sign with a similar purpose, for example hôpital and forêt were pronounced hospital and forest.
People in some parts of France, like Paris, sound the E on the ends of some words as a short UH as in uh-huh. More technically it's called a schwa. So école would be écol - uh.
In the 12th century, the modern French word guêpe was written guespe and pronounced gwesp. The English mutated it by dropping the G and pronounced it wesp and then wasp.
Sometimes words split into further separate speaker populations after the initial isolation to create a kind of sub-species. In some parts of England like the West Country where I'm from, the G of guespe didn't die off but the W did. As G is not hard when followed by E (as in gesture) and the final E of guespe was sounded as a schwa, pronunciation went gwesp - jesp- jespa and that's why we yokels call wasps jaspers.
What the connection is with the old song 'Oh Sir Jasper do not touch me' is not known.
*If you're a linguist, yes I know I'm simplifying and being a little elliptical.