Published: 30 Jun 2014 | Last Updated: 02 Jul 2014 12:55:59

Four broadcasts for Radio 4's "Just So Science" series airing on consecutive afternoons at 13.45 on 24 to 27 June. Prof John Hutchinson contributes to "Old Man Kangaroo" on Wednesday 25 and "The Elephant's Child" on Friday 27 June.