We went to a museum together and looked at all the skulls dating back 7 million years to today.
He grasped the fact that it's a slow process of change and that it is small changes that take place. So inspite of the fact there are not more skulls and links there is a picture and there is evidence that humans came from a common ancestor.
I will do some of the recommended reading too.
Thanks everyone for your input except WMF.
Kate xx