Macroevolutionary dynamics of nectar spurs, a key evolutionary innovation.

@article{FernndezMazuecos2019MacroevolutionaryDO,
  title={Macroevolutionary dynamics of nectar spurs, a key evolutionary innovation.},
  author={Mario Fern{\'a}ndez‐Mazuecos and Jos{\'e} Luis Blanco‐Pastor and Ana Juan and Pau Carnicero and Alan Forrest and Marisa Alarc{\'o}n and Pablo Vargas and Beverley J. Glover},
  journal={The New phytologist},
  year={2019},
  volume={222 2},
  pages={
          1123-1138
        }
}
Floral nectar spurs are widely considered a key innovation promoting diversification in angiosperms by means of pollinator shifts. We investigated the macroevolutionary dynamics of nectar spurs in the tribe Antirrhineae (Plantaginaceae), which contains 29 genera and 300-400 species (70-80% spurred). The effect of nectar spurs on diversification was tested, with special focus on Linaria, the genus with the highest number of species. We generated the most comprehensive phylogeny of Antirrhineae… 

Tables from this paper

Accelerated diversification correlated with functional traits shapes extant diversity of the early divergent angiosperm family Annonaceae

The results show that the high species richness in Annonaceae is likely the result of recent increased diversification rather than the steady accumulation of species via the ‘museum model’, and indicates heterogeneity in diversification rates across the phylogeny.

A tale of worldwide success: Behind the scenes of Carex (Cyperaceae) biogeography and diversification

The megadiverse genus Carex (c. 2000 species, Cyperaceae) has a nearly cosmopolitan distribution, displaying an inverted latitudinal richness gradient with higher species diversity in cold‐temperate

Adaptation to hummingbird pollination is associated with reduced diversification in Penstemon

Examining macroevolutionary processes affecting floral pollination syndrome diversity in the largest North American genus of flowering plants, Penstemon, finds that hummingbird‐adapted species are expected to remain rare due to their reduced diversification rates, and predicts the expected pattern of floral diversity within Pen stemon over time.

Out of the Mediterranean Region: worldwide biogeography of snapdragons and relatives (tribe Antirrhineae, Plantaginaceae)

The Mediterranean Region played a key role in the origin of the current distribution of the Antirrhineae, and the higher species richness found in this region appears to be the result of a time-for-speciation effect rather than of increased diversification rates.

Alpine speciation and morphological innovations: revelations from a species-rich genus in the northern hemisphere

It is concluded that geological influences (mean altitude and topographic heterogeneity), glacial–interglacial climate stability and phylogenetic conservatism have together promoted the speciation and adaptive evolution of the genus Saussurea.

Do key innovations unlock diversification? A case-study on the morphological and ecological impact of pharyngognathy in acanthomorph fishes

Whether transitions to pharyngognathy led to shifts in the rate of phenotypic evolution, as well as shifts and/or expansion in the occupation of morphological and dietary space, is investigated using a dataset of 8 morphological traits measured across 3,853 species of Acanthomorpha.

Manipulation of trait expression and pollination regime reveals the adaptive significance of spur length

The study illustrates how combining trait manipulation with analysis of causes and strength of phenotypic selection can illuminate the functional and adaptive significance of trait expression when trait variation is limited.

Geo-Climatic Changes and Apomixis as Major Drivers of Diversification in the Mediterranean Sea Lavenders (Limonium Mill.)

It is found that Limonium species diversity on the Canary Islands and Cape Verde archipelagos is the product of multiple colonization events followed by in situ diversification, and that woodiness of the Canarian endemics is indeed a derived trait but is not associated with a significant shift to higher diversification rates.

THE DIVERSIFICATION OF HALENIA (GENTIANACEAE): ECOLOGICAL OPPORTUNITY VERSUS KEY INNOVATION

It is shown that Halenia originated in East Asia and migrated via North America into Central America, and from there, it colonized South America three times independently, probably within the last million years.

Floral Nectar Spurs and Diversification

  • S. Hodges
  • Biology
    International Journal of Plant Sciences
  • 1997
The data indicating that the evolution of floral nectar spurs represents a key innovation in Aquilegia and many additional groups are reviewed, providing strong support for the key innovation hypothesis.

Corolla morphology influences diversification rates in bifid toadflaxes (Linaria sect. Versicolores).

It is confirmed that different forms of floral specialization can lead to dissimilar evolutionary success in terms of diversification and suggested that opposing individual-level and species-level selection pressures may have driven the evolution of pollinator-restrictive traits in bifid toadflaxes.

Evolution of nectar spur length in a clade of Linaria reflects changes in cell division rather than in cell expansion

It is found that changes in cell number and therefore in cell division largely explain evolution of spur length, which contrasts with previous studies in Aquilegia which have found that variation in nectar spur length is due to directed cell expansion over variable time frames.

Spurring plant diversification: are floral nectar spurs a key innovation?

  • S. HodgesM. Arnold
  • Biology
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1995
It is shown that patterns of diversification within and among clades that have evolved floral nectar spurs strongly support the hypothesis that floral n dessert spurs represent a key innovation.

Pollinator shifts drive increasingly long nectar spurs in columbine flowers

Using a species-level phylogeny of the columbine genus, Aquilegia, a significant evolutionary trend for increasing spur length during directional shifts to pollinators with longer tongues is shown and evidence for ‘punctuated’ change in Spur length during speciation events is found, suggesting that AquileGia nectar spurs rapidly evolve to fit adaptive peaks predefined by pollinator morphology.

Spurring plant diversification : Are floral nectar spurs a key innovation ?

This work considers whether ancestral reconstruction of continuous traits should reflect an underlying evolutionary model of the process that describes or dictates trait evolution, and how traits may be transformed to better meet an appropriate distribution.

Seed size and its rate of evolution correlate with species diversification across angiosperms

It is shown that absolute seed size and the rate of change in seed size are both associated with variation in diversification rates, and that smaller-seeded plants had higher rates of diversification, possibly due to improved colonisation potential.

PHYLOGENETIC ANALYSIS OF TRAIT EVOLUTION AND SPECIES DIVERSITY VARIATION AMONG ANGIOSPERM FAMILIES

A molecular phylogeny of the angiosperm families is used to reanalyse correlations between S and family‐level traits and use reconstructions of trait evolution to interpret the results and confirm that pollination mode and growth form are correlated with S.
...