**7. Taxonomic effects in herbicide-resistant weeds and deployment of resistant crops**

Evolved herbicide resistance (EHR) has become a threat to agriculture around the world [12, 160, 161]. Evolved herbicide resistance in weeds was initially reported in 1970 and generally considered during the 1970s throughout the 1990s [80, 162]. The rate of instances has precipitated significantly during those decades. Up to now, the advancement of imperviousness to various herbicides with various mode of action has additionally been detected inside various weed species [51]. The detection of resistance to glyphosate, and the introduction of transgenic glyphosate-resistant crops in the 1990s, also the recent expansion of cases of evolved resistance to glyphosate in weeds, likely because to greater glyphosate usage, have inspired a renewal of interest and resurgence of research into this phenomenon [113, 163].

In spite of four decades of research on evolved herbicide resistance, it is unclear wherefore a few weeds develop resistance quicker than others. Baker's list of specifications which may be anticipated in the "ideal weed" is excellent recognized; one may anticipate that weeds with evolved herbicide resistance will have a subset of these qualities [164]. This perception was ascribed to chance, as lots of resistant weeds among the world's worst weeds, are widespreading, and happen in many cropping systems [165–167]. Well before evolved herbicide resistance was detected, inheritable variability, breeding system, reproductive valence, and population size were predicted to associate with development of herbicide resistance [168]. Other plant variables can influence the development of resistance, including change recurrence, generation time, and compatibility in lack of the herbicide, pliancy, and soil seed repository, and in addition, method of legacy of resistance, size of population, seed dormancy, and gene flow by pollen and seed [121, 169]. Whenever these factors have been tested in models predicting evolution of resistance, few have been examined empirically [168, 170].

In spite of relatively cohesive internally of taxonomic families, there are usual differences in terms of ecological properties among them; in fact, evolved herbicide resistance does not occur randomly among weed or crop species. Generally, depending on perceptions and reportages of the tendency for resistance to evolve within certain genera or species, evolved herbicide-resistant weeds are distinct ecologically and taxonomically toward other weeds [171]. Some researchers found the same trends for subsets of weeds with EHR to acetolactate synthase (ALS), photosystem II (PSII), and 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase-inhibitor herbicides and with multiple resistances. Comparing taxonomic and life history traits of weeds with EHR to a control group ("the world's worst weeds"), we found weeds with EHR significantly overrepresented in certain plant families and having certain life history biases [171].
