GY9 Change and ‘need’

Is it something that changes over time, for the better, or indeed, for the worse? Maybe an animal, like a giraffe, grew a longer neck to get their food that they needed, so that evolved over time. I think that giraffes don’t just stay…. before they grew the long necks, they had a shorter neck and they weren’t getting enough food that they needed so that’s why they grew the long neck – over time though, it didn’t just happen straight away; it happened over years so they could get the nutrition or the thing or whatever they needed.