If you go from 10 expected births to 1000, the expected gain only increases by 70%. That’s great, but we’re still limited to selecting the maximum value from a normal distribution. So the increase is smaller than many people believe.
This is because the expected gain of embryo selection using a predictor is roughtly directly proportional to the correlation between the predictor and the trait of interest but only the square-root of the log of the number of embryos! Having more embryos to choose from is great, but the best embryo of 1000 or even 10 isn’t likely to be chosen for implantation if your predictor isn’t very good.
This is because the expected gain of embryo selection using a predictor is roughtly directly proportional to the correlation between the predictor and the trait of interest but only the square-root of the log of the number of embryos! Having more embryos to choose from is great, but the best embryo of 1000 or even 10 isn’t likely to be chosen for implantation if your predictor isn’t very good.
https://doi.org/10.1016/j.cell.2019.10.033