Ancient civilization greatly depended on local flora and fauna for their
survival and experimented with various berries, roots, leaves, minerals or
animal parts to find out what effects they had and as a result, many crude drugs
were observed by the local healer to have some medical use. As understanding of
therapeutic benefits deepens and demands for natural products increased,
previously serendipitous discoveries evolved into active searches for new
medicines. At present 25 per cent of the modern medicines are developed from
plants that were first used traditionally, and many synthetic drugs have also
been obtained from natural precursors.