Scrapheap Challenge last minute when one team couldn't travel due to a livestock epidemic. Both US teams made it to the final round. Series 9 was shown in two halves. The first eight episodes aired between 15 April and 3 June, and the remaining episodes between 4 November and 23 December 2007. Series 11 saw Dick Strawbridge (formerly a competitor from series 1-3) return as an expert and judge, replacing Robert Llewellyn. The show was now produced by RDF Bristol and Exec. producer Jane Lomas and series producer John Macnish had to deliver the new series on a fraction of the budget
Challenge hypothesis However, during periods of heightened male aggression, testosterone levels increase further to a maximum physiological level. This additional boost in testosterone appears to facilitate male-male aggression, particularly during territory formation and mate guarding, and is also characterized by a lack of paternal care. The challenge hypothesis has come to explain patterns of testosterone production as predictive of aggression across more than 60 species. The challenge hypothesis presents a three-level model at which testosterone may be present in circulation. The first level (Level A) represents the baseline level of testosterone during the non-breeding season. Level A is presumed to maintain feedback