what is the {end time} for {Thomas Hunt Morgan} has {chairperson} as {American Association for the Advancement of Science} ?
On what date did Thomas Hunt Morgan retire as the chairperson of AAAS?
When did Thomas Hunt Morgan stop being the chairperson at the American Association for the Advancement of Science?
SELECT ?c WHERE { resource:Thomas_Hunt_Morgan property:chairperson ?o . ?o property:end_time ?c . ?o property:chairperson resource:American_Association_for_the_Advancement_of_Science }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q177681> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P488> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q40358> .
?statement <http://www.wikidata.org/entity/P582> ?value. 
} 

SELECT ?value WHERE { wd:Q177681 p:P488 ?s . ?s ps:P488 wd:Q40358 . ?s pq:P582 ?value}