See introduction on TL4458 : Newton and the spectrum. Charles Darwin was only 26 when he visited the Galapagos, but Quentin Blake has not let this fact influence his drawing.
The 'student accommodation' pic is actually the library of Darwin College - I don't think any of it is student rooms. One of the nicer examples of 1970s (?) architecture in Cambridge, I think. Incidentally the old part of Darwin (just visible on the left) was owned by Charles Darwin's family.