Jack of all trades, master of some? On the role of phenotypic plasticity in plant invasions

TLDR

Phenotypic plasticity is widely regarded as a key factor in plant invasions, with hypotheses that invasive species are more plastic than natives and that introduced populations evolve greater plasticity than native ones. The authors aim to delineate the requirements for assessing plasticity at different levels and introduce a framework distinguishing jack‑of‑all‑trades, master‑of‑some, and jack‑and‑master strategies for invaders. They analyze genotype‑ versus species‑level experimental tradeoffs, outline essential design components for detecting plasticity, and review recent literature examples.

Abstract

Invasion biologists often suggest that phenotypic plasticity plays an important role in successful plant invasions. Assuming that plasticity enhances ecological niche breadth and therefore confers a fitness advantage, recent studies have posed two main hypotheses: (1) invasive species are more plastic than non-invasive or native ones; (2) populations in the introduced range of an invasive species have evolved greater plasticity than populations in the native range. These two hypotheses largely reflect the disparate interests of ecologists and evolutionary biologists. Because these sciences are typically interested in different temporal and spatial scales, we describe what is required to assess phenotypic plasticity at different levels. We explore the inevitable tradeoffs of experiments conducted at the genotype vs. species level, outline components of experimental design required to identify plasticity at different levels, and review some examples from the recent literature. Moreover, we suggest that a successful invader may benefit from plasticity as either (1) a Jack-of-all-trades, better able to maintain fitness in unfavourable environments; (2) a Master-of-some, better able to increase fitness in favourable environments; or (3) a Jack-and-master that combines some level of both abilities. This new framework can be applied when testing both ecological or evolutionary oriented hypotheses, and therefore promises to bridge the gap between the two perspectives.