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Evolution Of Orchids

Explore recent fossil findings shedding light on the evolution of orchids, from the first orchid fossil to molecular clock analysis, providing a deeper understanding of orchid lineage origins and diversification.

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Evolution Of Orchids

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  1. Evolution Of Orchids Learning From Recent Fossil Discoveries Christinia Schoch

  2. 2011

  3. 2009

  4. Before Orchid Fossils • Freudenstein and Rasmussen (1999) • What does morphology tell us about orchid relationships? – A cladistic analysis. • Compared 54 morphological characters and 103 taxa • Excluded 10 previously studied characters • Used Hypoxis as the outgroup • Used genotype level correction (generic exemplar approach) for missing characters unless a known polymorphism was present • Analyzed for shortest trees and trees with highest fitness

  5. 13 4 4 9 6 5 7 6

  6. 27 – anther orientation (0=erect, 1=bend late, 2=bend early) • 31 – basal caudicals (0=absent, 1=present) • 32 – hammer stipe (0=absent, 1=present) • 33 – tegula (0=absent, 1=present) • 34 – pollen unit (0=monad, 1=tetrad) • 38 – massulae (0=absent, 1=orchidoid, 2=epidendroid) • 39 – pollinuim texture (0=granular, 1=solid) • 40 – pollinium number: 2 (0=absent, 1=present) • 41 – pollinium number: (0=absent, 1=longitudinal, 2=transverse) • 42 – pollinium orientation (0=juxtaposed, 1=superposed) • 44 – stigma (0=protruded, 1=sunken) • 46 – viscidium (0=none, 1=diffuse, 2=detachable)

  7. The First Orchid Fossil

  8. The First Orchid Fossil • Ramirez et al (2007) • Dating the origin of the Orchidaceae from a fossil orchid with its pollinator. • Discovered in Dominican Republic in 2000 • Aged the amber as per Iturralde-Vinent (1996) at 15-20 Myr • Used morphological characteristics of pollinarium to identify potential taxa • Compared 129 shortest trees for cladistic position • Compared 25 morphological traits and 15 taxa • NPRS and PL for aging lineage • Genbank plastid DNA sequences for 60 genera • Used Asparagales as the outgroup

  9. Flower: 3 Pollinarium: 10 Pollen (micro): 10 Pollination: 2

  10. 3 – anther orientation (0=erect, 1=bent) • 4 – basal caudicals (0=absent, 1=present) • 5 – hamulus stipe (0=absent, 1=present) • 9 – tegula stipe (0=absent, 1=present) • 20 – pollen unit (0=monad, 1=tetrad) • 14 – massulae (0=absent, 1=present) • 13 – pollinuim texture (0=granular, 1=massulate) • 12 – pollinium number (0=2, 1=4, 2=>4) • 11 – pollinium orientation (0=juxtaposed, 1=superposed) • 2 – stigma (0=protruded, 1=flat or slightly convex) • 6 – viscidium (0=none, 1=diffuse, 2=detachable)

  11. Goodyera Ludisia Zeuxine Gomphicus Spiranthes Ponthiera Altensia Epipactus Chloraea Listeria Nervilia

  12. Molecular clock chronogram estimated via penalized likelihood using 50% Majority-Rule consensus topology of the family Orchidaceae when using the oldest bound ages of fossil calibrations. • Dashed branches subtend nodes with posterior probabilities below 0.95. • Circles indicate age-constrained nodes. • Out = Outgroups, • Apo =Apostasioideae • Cyp = Cypripedioideae • Orc = Orchidoideae • Epi = Epidendroideae • H.epi = Higher Epidendroids • Goo = Goodyerineae

  13. The Oldest Orchid Fossils • Conran et al. (2009) • Earliest orchid marcrofossils: Early Miocene Dendrobium and Earina (Orchidaceae: Epidendroideae) from New Zealand. • Discovered in New Zealand in diatomite from a mine • Aged the fossils using spore and pollen data located in surrounding sediments as per Bannister et al. (2005) • Used morphological characteristics of leaves and holotype cuticles to identify potential relationships to modern species of Orchidaceae. • Compared morphological characters to previously known cladograms and modern specimens of suspected genera to identify location within Orchidaceae.

  14. Using the Fossil Record • Gustafsson et al. (2010) • Reassessing the temporal evolution of orchids with new fossils and a Bayesian relaxed clock, with implications for the diversification of the rare South American genus Hoffmannseggella. • Used the descriptions of fossils found by Ramirez (2007) and Conran et al. (2009) to look at the age of the evolution of Orchidaceae. • Compared Bayesian relaxed clock in BEAST and PL in r8s methods of estimating clade age. • Compared newly aged phylogenetic tree with ancient global climate data.

  15. Summation • Without fossil evidence, orchid phylogenitic trees could only be based off of morphological characteristics of modern species. • Fossil evidence provided information to place extant species within the trees of Orchidaceae and age orchid phylogeny. • Orchids are much older than originally thought, with a most recent common ancestor in the Late Cretaceous period. • Orchid diversification began in a period of global cooling, not global warming.

  16. Older Than You Thought! • http://www.danitadelimont.com/galleryinterestinginsects.asp • http://www.flickr.com/photos/23111015@N04/4632545761/ • http://www.atshq.org/boards/viewtopic.php?f=7&t=24375 • http://www.orchisasia.org/genre/Goodyera/goodyera%20schlechtendaliana/index.html • http://www.orchidspecies.com/goodpubescens.htm • http://www.flickr.com/photos/dcoblitz/2252193149/ • http://yamello.blogspot.com/2010/09/biology-of-orchid-seed-germination.html • http://www.orchidspng.com/leaf_struct.html • http://www.botanicaufpr.blogspot.com/ • http://www.orchidboard.com/community/beginner-discussion/11429-firm-brown-roots.html • http://www.flickr.com/photos/wfalcon/4333993564/ • http://www.amjbot.org/cgi/content/full/94/1/47

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