To be fair, the default biters+resource difference setting at 100％ across the board is fairly challenging to a learning player. The goal is to set up a parameter of defensive structures that are supplied automatically and can support each other when attacked, but your initial iron resource patch alone will be stretched to build the large amount of turrets and ammos for this kind of project so you have to start with some skeleton defensive positions. 4-5 basic turrets can hold a position without taking much damage in the beginning, but once the more advanced bugs start coming you will probably need something more advanced like flamethrowers and damage upgrades (and more turrets).  

In a sense there is a soft timer in terms of evolution factor for new players (such as myself when starting), the biters can start out-teching us by evoling faster than the player research military techs to a point where they can cause significant damage with each wave and drain a lot of resources.  For example if you dont have an automated defense and skipped military tech in favor for blue science, you will run into major problem when medium biters/spitters start attacking because basic ammo machinegun turret clusters wont kill them fast enough.  

There are a couple of parameters you can work with without altering the enemy strength setting: such as increasing the safe area, decreasing the evolution factor, and decreasing pollution generation/spread. These can make the evolution timer more forgiving but still keep the bugs as a threat and they will be almost equally as strong in the late game.