When it comes to science, bias is irrelevant. Any person with any bias can do the exact same experiment and get similar or identical results. For example, if you take one person who believes water boils at 100°c and another who believes it needs to be 100°f, all you need to do is take a thermometer that reads in celsius, heat up the water and measure the temperature at which it boils. The one who believes it boils at 100°c will be vindicated, and the one who believes it boils at 100°f doesn’t have a leg to stand on. You can do that same experiment once, twice, 5 times, 10 times, even 100 times, it will always yield the same results. That’s what real science is.
But there isn’t a single experiment that can be done to verify Evolution. No matter how many laboratories you visit, no matter how many scientists you ask, not one scientific experiment can be done to demonstrate that Evolution happened, or even can happen, to someone who does not have a pre-existing set of biases. Evidence for Evolution does rely on personal bias. It is therefore not science, but religion.