Phonological Evolution (or sound shifts), along with Lexical Evolution and Grammatical Evolution are used to make a Conlang more Naturalistic by evolving from a proto-conlang to a modern variety.
This is how to do that, or at least the Phonological Evolution.
We also cover Vowel Harmony… yay.

Chapters:
0:00 Evolution?
0:46 Shift Rules
1:30 Types of Shift
3:34 Tone Example
5:20 Vowel Harmony
6:31 New Vowels
7:56 Strong & Weak Consonants
10:18 Rhotic Loss
11:04 Application
11:42 Loss of Distinction
12:58 Outro

This content is intended for teenage audiences and up.
All clips used under fair use for the purpose of education

Music:
Adventure by Alexander Nakarada
Link: https://filmmusic.io/song/6092-adventure
Neverland by Alexander Nakarada
Link: https://filmmusic.io/song/6348-neverland
Folk Round by Kevin MacLeod
Link: https://filmmusic.io/song/3770-folk-r...
Celtic Impulse by Kevin MacLeod
Link: https://filmmusic.io/song/3484-celtic...
All under License: http://creativecommons.org/licenses/b...