Why did the children being evacuated wear labels round their necks?
As identification. There had to be some means of identifying them and where they were to go.
Darwin's explanation of Giraffes having long necks would involve the longest-necked giraffes surviving, and then their children exhibiting more survival-important characteristics. This is in contrast to Lamarck's explanation, where the giraffes stretch their necks as they reach for higher leaves, and this characteristic being passed down because it had changed in the parent. Modern biology easily disproved Lamarck's idea of changed traits being inherited.
The ancestors of giraffes really had short necks. When they reproduced, some of their children were mutated to have longer necks. The mutated giraffes could reach the trees to eat so ,overtime, the population of normal giraffes decreased and the population of mutated giraffes increased. - Not true. There are many scientific sites on the internet disproving this theory. They probably evolved long necks to fight against other giraffes.
bolt on necks are cheaper than set necks, and set necks are cheaper, than neck through. bolt on necks have less sustain but are cheap and easy to repair. set necks have more sustain, are expensive and harder to repair than bolt-on. neck through has more sustain than set neck but is more expensive and harder to repair than set neck.