It seems incredible, that despite the number of scientist working in the world today, and the number that have worked over human history, there are still important discoveries being made.
One of the most interesting discoveries of recent times, is that sperm – in particular human sperm, does not move as we thought. For decades school textbooks have shown sperm rather like a tadpole – it would appear that this is wrong. What is funny is that the reason for our mistake is that scanners to look at things this small, generally work in 2 dimensions, and looking at sperm like this it does indeed look like they are wriggling a tail.
It turns out that when viewed in 3 dimensions, they are actually spinning. This does indeed propel them forwards but clearly is a completely different type of action, and likely requires a far simpler body.
What else is there left to find? In the natural world, the problem is that without accelerated discovery the wildlife is destroyed before we even know any of its secrets.