Evolutionary history of_plantsPresentation Transcript
Evolutionary History ofPlants
Land plants are said to have evolved from green algae. This isbecause of the many common characteristics that land plantsshare with the green algae called charophytes. Both haverosette-shaped cellulose-synthesizing complexes, peroxisomeenzymes, flagellated sperm structure, and the formation of aphragmoplast. The charophytes lived on the edges of pondsand lakes in the shallow water, so when there were periods ofdrying the charophytes that could survive would reproduce tomake more charophytes that were more and more accustomedto the dry ground. These are the first land plants. Land plantshave four main adaptations that set them apart from theirgreen algae ancestors. These traits are the alternation ofgeneration and multicellular, dependent embryos, walledspores produced in sporangia, multicellular gametangia, andapical meristems. The oldest plant that has been unearthed sofar is from Oman, where plant spores were found embeddedin plant cuticle material that are 475-million-years-old.