Sure, it's completely realistic for a biology student (or any other discipline) to serve in a junior or line developer position in many corporate environments. If you're just wiring Spring beans together, writing test cases, or doing basic sysadmin work there's not much CS doing on.

My experience is that the differences show as you become more senior or you want to do things off the beaten path. Once you start dealing with comprehensive troubleshooting (back-to-front), non-trivial data modeling, and architecture the lack of fundamentals starts to slow you down. Understanding a DAG is pretty important in certain cases, and if you weren't exposed to it that's alot of outside learning. It's doable, but you have to put in more and more personal time to keep up. Whereas the CS folks are building on at least passing knowledge over four years of study.

To put my biases on the table, I'm a self-taught dev that went back for my BS degree. I have strong bias towards the value of a CS education.

There is plenty of time for someone to learn about DAGs (really, they're not rocket science) while they're a junior dev, and a bright person, given a series of tasks slightly increasing in complexity and difficulty, will have no trouble learning the fundamentals.

Most of my CS classmates were much more interested in going to school to get their degree to become the next Mark Zuckerberg or maybe work for him. They'd cram for tests between beer pong and bong hits and forget 90% of what they were there to learn. I'd rather hire someone who is bright with any college degree (best programmer where I worked at in my last job had a Masters in dramatic arts) than a random somebody with a CS background. Everything I need in theory from a junior dev can be tested during an interview - it doesn't take a rocket scientist to know what quicksort is, or how to write documentation, or how to create a new class in Java without using an IDE.

I guess the major difference is that I don't see a CS degree as a sign of a good programmer. I see it as a sign that someone endured classes for four years, and I am open to the possibility that someone with another degree might be a better fit at a junior level than anybody with a CS degree that bothered to respond to the job posting.

There's no reason that a bright student with Chinese poetry background couldn't be a perfect fit. But I think there's reasons why we still have CS degrees even though there's no reason why any bright person can't teach oneself coding. OTOH, if you go this route and say CS degree doesn't matter at all, just drop any connection to degrees and hire people based on tests or something - why link it to biology?

I wouldn't link it specifically to a biology degree, but my initial response was to someone who asked about it specifically.