Monocots (including such groups as grasses, palms, orchids, and philodendrons) include more than 65,000 species of flowering plants, occur in almost all habitats, and provide the great majority of the human diet. A definitive family tree for this group will be developed and used to understand the broad-scale evolution of monocots over geologic time. A total of 23 genes in 601 species, whole chloroplast genomes in 175 species, and all genes expressed in 50 species will be sequenced and used to reconstruct the evolutionary history of this group. Additionally, phenotypic data from living and fossil species will be collected, and all data will be analyzed integratively to provide a comprehensive understanding of monocot evolution.
The resulting family tree will provide the foundation for many new studies in physiology, ecology, biogeography, and genomics of flowering plants. Web access to all data and results will be provided to researchers and K-12 teachers and students. Several post-doctoral fellows, graduate students, and undergraduates (with a focus on women and minorities) will be trained, and four young faculty will be supported. A museum exhibit on the evolution of flowering plants will be produced for high-profile venues in New York, Chicago, Denver, and Berkeley, and a children's monocot garden exhibit will be developed at the New York Botanical Garden. Posters illustrating monocot diversity and evolution will be distributed to colleges, and staff will give talks at public high schools.
Monocotyledons are a group of more than 65,000 species, comprising ca. 25% of all flowering plants. Monocots radiated extensively over the past 130 million years, invaded almost all terrestrial and near-shore habitats, dominate several, and directly/indirectly provide the great majority of the human diet. Monocots exhibit kaleidoscopic variation in anatomy, morphology, physiology, ecology, and geographic distribution. Understanding their origin, phylogeny, diversity, and patterns of convergent and divergent evolution thus presents a major challenge to evolutionary biologists. The goals of the Monocot AToL were to (1) develop a phylogeny using genomic approaches by using sequences of whole chloroplast genomes for 600 species representing all monocot families and subfamilies and entire transcriptomes (genes expressed during the emergence of developing leaves) for a further subset of 150 species; (2) score more than 200 features of structure, chemistry, and development in all 600 species as well as critical monocot fossils with the data stored in MorphoBank and made publicly available on that website; (3) analyze all of the available data to identify features that diagnose current and fossil groups in teh monocot tree of life; (4) critically evaluate the position of several fossil monocots in time with respect to the fossil record to derive a new timeline for monocot evolution; (5) assess patterns of morphological, ecological, and biogeographic changes through time among the monocots using the new molecular and morphological data obtained in the study; (6) provide interdisciplinary training for several post-docs, graduate students, and undergraduates. In conducting this project, many species the were previously poorly know were wild collected and samples placed in permanent DNA collections, permanent frozen tissue collections living collections, and as voucher specimens in museums such as the New York Botanical Garden Herbarium and other herbaria. To date several papers have been published that present the reconstruction of the evolutionary history of the major clades of the monocots. In doing these, several features were discovered in the structural aspects of the fruits and the leaves that allow us to better understanding the changes in these features through time and in fossils. In particular, it was discovered that fleshy fruits have evolved several times within the monocots (i.e., that there are independent origins of these fruits) indicating that there are different developmental pathways. This is in fact true. An REU Student on this grant conducted part of that study for her Honors Thesis at Oberlin College. She was able to demonstrate that the tissue layer that expands into the fleshy part of the fruit is derived from different region of the young fruit in each different branch in the history of the monocot evolution. Further studies of the genes involved will be of value in the fruit crop industry across the flowering plants. Similarly, the study of leaf clearings of living species, that is the leaf ‘skeleton’, has revealed features that allow us to identify fossils, place them within monocot families, and further identify the point in time when these groups evolved and track the history of both features and genes through time. These are but two examples of the wealth of molecular and biological data acquired during this project, which has lead ta better understanding of the biology of the monocots, their ecology, and the world around us.
