REVIEW & INTERPRETATION A Comparison between Crop Domestication, Classical Plant Breeding, and Genetic Engineering

ABSTRACT genes are literally shot into plant cells) and a variant, particle discharge (Birch, 1997).Several claims have been made about genetic engineering (GE) GE has now reached the commercial stage. New culti-in comparison with crop domestication and classical plant breeding, including the similarity of genetic changes between those taking place vars of maize (Zea mays L.), soybean [Glycine max (L.) during domestication and by GE, the increased speed and accuracy Merr.], cotton (Gossypium spp.), papaya (Carica papaya of GE over classical plant breeding, and the higher level of knowledge L.), etc. have been developed that carry additional genes about the actual genes being transferred by GE compared with classi- conditioning traits as diverse as resistance to insects, cal breeding. In reviewing evidence pertaining to these claims, I sug- viruses, and herbicides. Some of these cultivars havegest that (i) it is unlikely that changes introduced by GE will make been readily adopted by farmers because they greatlycrops weedier, although exceptions have been noted, (ii) changes facilitate the management of crops (e.g., Delannay etbrought about by GE currently often involve gain-of-function muta-al., 1995: herbicide resistance), provide a more effectivetions, whereas changes selected during domestication generally in-volve loss-of-function mutations, (iii) adoption of GE cultivars has alternative to current control methods [e.g., Bolin et been much faster than any previous introduction and spread of agricul- al., 1996: resistance to European corn borer, Ostrinia ture that occurred earlier but has occurred at about the same rate as nubilalis (Hbner), in maize], or offer the only viable the spread of cultivars obtained by plant breeding, (iv) introduction possibility of disease control in the absence of any natu-of agriculture reduced the health of agriculturists compared with tha