Can a Christian believe in evolution?

Yes - a Christian can, and many orthodox, Bible-believing Christians do. The worry is understandable: evolution - common descent and natural selection over deep time - has real converging support from genetics and the fossil record, so doesn't accepting it mean contradicting Genesis, or shrinking God down to an unnecessary spare part?

The first thing to say is that Bible-believing Christians genuinely hold a range of positions here - young-earth creation, old-earth creation, and evolutionary creation - and this is a question on which sincere believers disagree in good conscience. It isn't ours to referee. One distinction many of them find clarifying is this: Genesis and biology are answering different questions. Science asks how - by what mechanism, over what timescale. Genesis answers who and why: that the universe had a beginning, that a personal God made it on purpose, and that human beings uniquely bear his image (Genesis 1:27). Those are not laboratory claims that a fossil could overturn.

So even if the biological mechanism turned out to be evolution, that would describe how God brought living things about - not whether a Mind stands behind them at all. 'Evolution, therefore no God' is not itself a scientific finding; it's a philosophical claim added on afterward. Science can tell you the process; it cannot tell you that the process is all there is. A Christian is free to follow the scientific evidence about mechanisms wherever it honestly leads, while holding firmly to what Genesis actually teaches: that behind everything there is an intentional Creator, and that you are made in his image on purpose - not by accident.