i am especially indebted to the work , and the speculations , of john alexander , mark boguski , edwin colbert , john conway , philip currie , peter dodson , niles eldredge , stephen jay gould , donald griffin , john holland , john horner , fred hoyle , stuart kauffman , christopher langton , ernst mayr , mary midgley , john ostrom , norman packard , david raup , jeffrey schank , manfred schroeder , george gaylord simpson , bruce weber , john wheeler , and david weishampel .