Resumen

CEVALLOS-FERRIZ, Sergio R.S.  y  HUERTA VERGARA, Alma R.. A history of success: biodiversity through fossils. TIP [online]. 2018, vol.21, suppl.2, e20180158.  Epub 02-Dic-2020. ISSN 1405-888X.  https://doi.org/10.22201/fesz.23958723e.2018.0.158.

Organisms develop and what evolves is the genome. In addition, if the innovation works, it goes ahead, if not it is selected. Thus, evolution is the successive accumulation of favorable events. The latter were recorded in the morphology and anatomy of the organisms conserved in the rocks as fossils. By comparing fossil and extant plants several outstanding episodes are recognized that show the sequence of modifications of photosynthetic organisms, beginning in the Precambrian and extending to the Recent. The first episode comprises from the origin of life to the colonization of the atmosphere by the biosphere; including the first planktonic and/or nektonic organisms, the first biofilms (it refers to communities of microorganisms that precipitate or trap minerals, to form organs-sedimentary structures) and millimeteric biological crusts, up to the intrusion of the atmosphere by plants that reach heights of a few decimeters. The colonization of the atmosphere by the biosphere with strong alteration of the lithosphere marks a second episode, in which homosporic plants, with unipolar embryo, unifacial vascular cambium and microphyll are found; these included centimetric plants that develop as shrubs and trees up to 20 m in height. A third episode is characterized by plants with bare seeds, bifacial vascular cambium, bipolar embryo and megaphylls, as well as a fascinating reproductive biology, different from that of extant plants. In the fourth chapter of this story, life reaches its maximum development with the appearance of a multicolored world full of aromas, which changes the relationships between plants and animals, promoting reengineering of processes related to the optimal use of water to complete life cycles. The four previous episodes are represented in diorams, illustrating "forests" or "jungles" similar to the extant ones, but with secrets in their biology that surprise for being original and different. Finally, the events presented are related to the economy of water in favor of life cycles with less dependence on this liquid, which facilitate the colonization of interior and high areas of the continents, thus reflecting a success story.

Palabras llave : photosynthetic organisms; vascular plants; evolution; biodiversity; water independence; fossils.

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