Question: How does the genome allow a brain to develop that has in born talents and tendencies-if we have an in born fear of say ,snakes,how does that get wired up in a brain?

Ruth Elderfield answered on 16 Jun 2015:

There is lots of debate (polite argument) between scientists and sometimes politicians, about how much of who we are is from our genes and how much is the environment in which we live, the Nature (genes) vs Nurture (environment) debate. This has been going on for a very long time.
A lot of who we are depends on our genes, our genetic code makes us, but we are also learning that what we eat and the chemical signals we receive in response to what is going on around us can change how those genes are switched on and off. So say that your fear was of spiders and your Dad also is afraid of spiders, you might think you have inherited that fear from your Dad in your genes. But as we are growing up we learn things, we may have inherited in our genes the biological pathways for a fear response (fight or flight) but we often have to tell it what to fear. You could have seen your Dad running away from the spider and thought ‘Dad thinks spiders are dangerous’. You would then instruct your brain that ‘spiders are dangerous’ and then use the fight/flight fear response when you see a spider.