How do people differentiate between personal beliefs and scientific evidence when discussing topics like evolution?

The distinction between personal belief and scientific evidence is fundamental in understanding how humans approach knowledge.

To distinguish between personal beliefs and scientific evidence, first you should have lots of knowledge about the topic of contention. You should be aware of the scientific evidence on the subject. What evidence and research say.

Then you should have the mindset to think critically without any biases, fallacies, or mental distortions and should be able to base your conclusions only on data-based evidence.

Personal beliefs are often based on faith, intuition, and personal experiences, and they do not require empirical evidence or logical justification.

In contrast, scientific evidence is based on empirical data collected through observation and experimentation, and it is subject to rigorous testing and verification.

Scientific knowledge is contingent and can be revised based on new evidence, while personal beliefs are not. This distinction is crucial for making informed decisions and understanding the world, as it encourages the use of evidence and logic in scientific inquiry.

Once you know all these things and are able to go the scientific thinking way, the differentiation comes automatically.

For instance, I know how evolution happens. I know about fossil evidence, transitional features, distribution in time and space, homologies, developmental biology, nested hierarchies, artificial selection, observations of evolution in the wild, various experiments in this regard and their conclusions. I am fully convinced about evolution after going through all the evidence that evolution is a fact.

So, if somebody says something contrary to all this without showing any evidence, I naturally think that is rubbish.

It is that simple and straight forward!