Evolutionary History of Plants

Land plants are said to have evolved from green algae. This is because of the many common characteristics that land plants share with the green algae called charophytes. Both have rosette-shaped cellulose-synthesizing complexes, peroxisomeenzymes, flagellated sperm structure, and the formation of a phragmoplast. The charophytes lived on the edges of ponds and lakes in the shallow water, so when there were periods of drying the charophytes that could survive would reproduce to make more charophytes that were more and more accustomed to the dry ground. These are the first land plants. Land plants have four main adaptations that set them apart from their green algae ancestors. These traits are the alternation of generation and multicellular, dependent embryos, walled spores produced in sporangia, multicellular gametangia, and apical meristems. The oldest plant that has been unearthed so far is from Oman, where plant spores were found embedded in plant cuticle material that are 475-million-years-old.