Tree of Life Gets New Branches
According to the Deep Green Phylogenetic Project, a consortium of 200 scientists from 12 countries, the plant kingdom actually consists of 4 different kingdoms. Their results, based on an analysis of 18S RNA and the chloroplast rbcL gene sequences, were presented at the 16th International Botanical Congress held in St. Louis, August 4.
The data presented suggested that green plants, red plants, and a third group comprised of algae and seaweed (brown plants) evolved from three separate one-cell plants. The most striking result was that another branch, fungi, is actually more related to animals than to plants. Hence, what had previously been thought of as the plant kingdom is actually four separate kingdoms, reflecting divergence that occurred before complex organisms evolved.
The group also found that most of the green plants living on land evolved from a single freshwater plant similar to the coleochaetes still extant today. The coelechaetes are nearly microscopic plants, which grow in a layer one-cell thick. According to Brent Mishler, a Deep Green leader from the University of California at Berkeley, the current findings contradict the dogma taught in every botany class today.
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