The evolution of flowers with deep corolla tubes


Some plants have evolved flowers of extraordinary depth, a phenomenon which puzzled Darwin1. Darwin suggested that the evolution of deep flowers could be a response to a kind of 'race' with pollinating insects: the length of the tongues of pollinating insects could increase as a result of a general size increase, or because it increased their nectar foraging efficiency. As this occurred, plants with relatively shallow flowers could be disadvantaged since pollen transfer, which is effected by physical contact between the pollinator and the anthers or stigma of the plant, could be reduced when the insect tongue is long relative to flower depth. This could lead to the evolution of increasing flower depth which in turn could drive the evolution of a further increase in insect tongue length. Various predictions of Darwin's proposal were tested here for orchid species with deep flowers that are pollinated by moths. It was found that insects do indeed insert their probosces no further than necessary to obtain nectar; that an experimental reduction in flower depth reduces both the male and female components of fitness; and that in natural populations there is a correlation between flower depth and female fitness measured by fruit set. These results all support Darwin's hypothesis to explain the evolution of flower depth.

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  1. 1

    Darwin, C. On the Various Contrivances by which British and Foreign Orchids are Fertilised by Insects (Murray, London, 1862).

    Google Scholar 

  2. 2

    Darwin, C. On the Origin of Species (Murray, London, 1859).

    Google Scholar 

  3. 3

    Rothschild, L. W. & Jordan, K. Novit. zool. 9 (suppl.), 1–972 (1903).

    Google Scholar 

  4. 4

    Nilsson, L. A., Jonsson, L., Rason, L. & Randrianjohany, E. Biol. J. Linn. Soc. Lond. 26, 1–19 (1985).

    Article  Google Scholar 

  5. 5

    Nilsson, L. A. Bot. Notiser 131, 35–51 (1978).

    Google Scholar 

  6. 6

    Miller, R. B. Evolution 35, 763–774 (1981).

    Article  ADS  Google Scholar 

  7. 7

    Gregory, D. P. Aliso 5, 357–419 (1963–1964).

    Article  Google Scholar 

  8. 8

    Nilsson, L. A. Bot. J. Linn. Soc. Lond. 87, 325–350 (1983).

    Article  Google Scholar 

  9. 9

    Nilsson, L. A., Jonsson, L., Ralison, L. & Randrianjohany, E. Biotropica 19, 310–318 (1987).

    Article  Google Scholar 

  10. 10

    Nilsson, L. A. & Rabakonandrianina, E. Bot. J. Linn. Soc. Lond. 97, 49–61 (1988).

    Article  Google Scholar 

  11. 11

    Miller, R. B. S. West. Nat. 30, 69–76 (1985).

    Google Scholar 

  12. 12

    Inoue, K. J. Fac. Sci. Tokyo Univ. 13, 285–374 (1983).

    Google Scholar 

  13. 13

    Grant, V. & Grant, K. A. Bot. Gaz. 144, 280–284 (1983).

    Article  Google Scholar 

  14. 14

    Grant, V. & Grant, K. A. Proc. natn Acad. Sci. U.S.A. 80, 1298–1299 (1983).

    CAS  Article  ADS  Google Scholar 

  15. 15

    Grant, V. Bot. Gaz. 144, 439–449 (1983).

    Article  Google Scholar 

  16. 16

    Darwin, C. On the Various Contrivances by which British and Foreign Orchids are Fertilised by Insects 2nd edn (Murray, London, 1877).

    Google Scholar 

  17. 17

    Inoue, K. Pl. Spec. Biol. 1, 207–215 (1986).

    Article  Google Scholar 

  18. 18

    Løjtnant, B. Feddes Rep. 89, 13–18 (1978).

    Article  Google Scholar 

  19. 19

    Vogel, S. Blütenbiologische Typen als Elemente der Sippengliederung (Fischer, Jena, 1954).

    Google Scholar 

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Nilsson, L. The evolution of flowers with deep corolla tubes. Nature 334, 147–149 (1988).

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