One theory by Ernst Haeckel, a German biologist and philosopher, stated that all organisms go through a "re-run" of evolution while in development.
His theory stated that all organisms go through a "re-run" of evolution while in development. One theory by Ernst Haeckel, a German biologist and philosopher.
One theory by Ernst Haeckel, a German biologist and philosopher. His theory stated that all organisms go through a "re-run" of evolution while in development.
One theory by Ernst Haeckel, a German biologist and philosopher. His theory stated that all organisms go through a "re-run" of evolution while in development.