source: [lemma=as] [tag=JJ] [tag=","] [□=□] □
destination: [lemma=as] [tag=JJ] [tag=","] [tag=□] □
spec: It is my understanding that there was no Cambrian “ explosion ” as such , just a prolongued period ( several million or tens of millions of years ) during which the rate of evolution was a bit higher than the average . The metasearch engine seems effective in that it displayed more relevant hits , and it also gave suggestions of other similar searches that you might be interested in .