Tamper - evident log with hash pointer
The current block is the child and the previous block the parent. If the parent changes in any way then this will cause a change in the previous block hash pointer of the child. So the change does not ripple back to the genesis block. However what this does do is that once a block has many generations following it then it makes it very difficult to change. So the genesis block as the first block is impossible to change because changing it would make it necessary to change the previous hash of every block that followed it.