American Society of Naturalists

A membership society whose goal is to advance and to diffuse knowledge of organic evolution and other broad biological principles so as to enhance the conceptual unification of the biological sciences.

“Meta-analysis shows that rapid phenotypic change in Angiosperms in response to environmental change is followed by stasis”

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Lucas D. Gorné and Sandra Díaz (Dec 2019)

Read the Article (Just Accepted)

Fast but limited: that’s how phenotypic change happens for plants faced with novel environmental conditions

Fast phenotypic change (at the time scales of years to a few centuries) in response to human-driven changes in the environment is known to occur in a wide range of wild plants and animals, but so far the information has been somewhat scattered. Gorné and Díaz have carried out a quantitative synthesis of the largest yet database of contemporary phenotypic change in plants. They find that plants are capable of a substantial amount of change in the first few years after environmental novelty and then remain stable. Although phenotypic plasticity may increase the initial response, the authors find an important proportion of heritable change. This pattern of abrupt change is general and independent from plant longevity and growth form, spatial scale (from few-meters-distant populations to populations on different continents) of analysis and from the type of trait (e.g. morphological, phenological). Interestingly, the authors report some unexpected patterns. First, long-lived species experience amounts and rates of change similar to short-lived ones. Second, those traits closely related to fitness display amounts and rates of change similar to morphological or physiological traits. Third, greater and faster divergence tends to occur between populations connected at the local scale, where gene flow can be intense, than between distant populations. This last, and the pattern of abrupt change, suggest that standing variability is crucial for adaptation in plants, and new adaptive variability is unlikely to arise in contemporary time-scales.


Abstract

The amount and rate of phenotypic change at ecological time scales varies widely, but there has not been a comprehensive quantitative synthesis of patterns and causes of such variation for plants. Present knowledge is based predominantly on animals, whose differences with plants in the origin of germ cells and the level of modularity (among others) could make it invalid for plants. We synthesized data on contemporary phenotypic responses of angiosperms to environmental change and show that if extinction does not occur, quantitative traits change quickly in the first few years following the environmental novelty and then remain stable. This general pattern is independent from lifespan, growth form, spatial scale or the type of trait. Our work shows that high amounts and rates of phenotypic change at contemporary timescales observed in plants are consistent with the pattern of stasis and bounded evolution previously observed over longer time frames. We also found evidence that may contradict some common ideas about phenotypic evolution: (1) the total amount of phenotypic change observed does not differ significantly according to growth form or lifespan, (2) greater and faster divergence tend to occur between populations connected at the local scale, where gene flow could be intense, than between distant populations, and that (3) traits closely related to fitness change as much and as fast as other traits.