The average human brain increases by 3.2% in terms of graymatter amount and 1.5% in terms of volume for every generation of humans due to epigenetic and mutational effects. This means that by 2500, the average human cranium will be around 85% larger than normal.
Human intelligence increases by 3 points every 10 years.
Since the Evolve timeline takes place at around 2300, or 300 years from now, it means a 90 IQ gain.
The average human will have an IQ of 190, while the smarter ones like Caira will have perhaps 220 or more.
So every human will be as smart as Christopher Michael Langan, or smarter.