Orthogenesis

French philosopher, Jesuit priest, and paleontologist

Baltic German scientist (1792-1876)

American paleontologist, geologist, and biologist (1840–1897)

Austrian botanist, paleontologist and evolutionary biologist (1875–1946)

American geologist and eugenicist (1857–1935)

Russian and Soviet geographer, biologist and ichthyologist (1876–1950)

Swiss botanist (1817–1891)

thumb|Evolutionary progress as a tree of life (biology)|tree of life. [[Ernst Haeckel, 1866]] thumb|upright=1.4|Lamarck's two-factor theory involves 1) a complexifying force that drives animal body plans towards higher levels (orthogenesis) creating a ladder of phyla, and 2) an adaptive force that causes animals with a given body plan to adapt to circumstances (use and disuse, [[inheritance of acquired characteristics), creating a diversity of species and genera. Popular views of Lamarckism only consider an aspect of the adaptive force.]] Orthogenesis is an obsolete biological hypothesis that

German zoologist (1843-1898)

Russian entomologist (1882-1930)

German zoologist (1840–1922)

German paleontologist (1896-1971)

French biophysicist and philosopher (1883-1947)

German paleontologist (1901-1985)

German zoologist (1855-1912)

Austrian zoologist (1874-1944)

American botanist (1888-1968)

Italian zoologist and evolutionary biologist (1857–1944)

German paleontologist (1882-1977)

German zoologist (1862–1937)