Developmental hypothesis

Put forward by Herbert Spencer (1820-1903) in 1852 as all-encompassing idea for change that could be applied to any organic phenomenon (across both developmental and evolutionary time), and praised by Thomas H. Huxley (1825-1895), Darwin’s ‘bulldog’ as something of a breakthrough in evolutionary theory.  It was part of Spencer’s own attempt at formulating an evolutionary theory that contained the notion of progression, as well as his belief in the inheritance of acquired characteristics. 

See Darwinism, Development, Developmental (or ontogenetic) time, Larmarckism, Ontogenetic development, Progress