Fast and frugal heuristics - simple rules for making decisions with realistic mental resources - are presented here. These heuristics can enable both living organisms and artificial systems to make smart choices, classifications, and predictions by employing bounded rationality. But when and how can such fast and frugal heuristics work? What heuristics are in the mind's adaptive toolbox, and what building blocks compose them? Can judgments based simply on a single reason be as accurate as those based on many reasons? Could less knowledge even lead to systematically better predictions than more knowledge? This book explores these questions by developing computational models of heuristics and testing them through experiments and analysis. It shows how fast and frugal heuristics can yield adaptive decisions in situations as varied as choosing a mate, dividing resources among offspring, predicting high school drop-out rates, and playing the stock market.

Simple Heuristics That Make Us Smart

Plants are finely tuned to the seasonality of their environment, and shifts in the timing of plant activity (i.e. phenology) provide some of the most compelling evidence that species and ecosystems are being influenced by global environmental change. Researchers across disciplines have observed shifting phenology at multiple scales, including earlier spring flowering in individual plants and an earlier spring green-up' of the land surface revealed in satellite images. Experimental and modeling approaches have sought to identify the mechanisms causing these shifts, as well as to make predictions regarding the consequences. Here, we discuss recent advances in several fields that have enabled scaling between species responses to recent climatic changes and shifts in ecosystem productivity, with implications for global carbon cycling.

https://www.cell.com/trends/ecology-evolution/pdf/S0169-5347(07)00130-9.pdf

Shifting plant phenology in response to global change

To achieve a coherent evolutionary theory, it is necessary to account for the effects of the environment on the process of development. Phenotypic plasticity is the change in the expressed phenotype of a genotype as a function of the environment. Various measures of plasticity exist, many of which can be united within the framework of a polynomial function. This function is the norm of reaction. For the special case of a linear reaction norm, genetic variation can be partitioned into portions that are independent and dependent on the environment. From this partition two heritability measures are derived which can be used, alternatively, to compare populations or make predictions about the response to selection. Genetically, plasticity is likely due both to differences in allelic expression across environments and to changes in interactions among loci; plasticity is not a function of heterozygosity. Plasticity responds to both artificial and natural selection. The evolution of plasticity is modeled in thre...

Genetics and Evolution of Phenotypic Plasticity

Null models in ecology

One view of pollination systems is that they tend toward specialization. This view is implicit in many discussions of angiosperm evolution and plant-pollinator coevolution and in the long-standing concept of pollination syndromes. But actual pollination systems often are more generalized and dynamic than these traditions might suggest. To illustrate the range of specialization and generalization in pollinators' use of plants and vice versa, we draw on studies of two floras in the United States, and of members of several plant families and solitary bee genera. We also summarize a recent study of one local flora which suggests that, although the colors of flowers are aggregated in phenotype space, there is no strong association with pollinator types as pollination syndromes would predict. That moderate to substantial generalization often occurs is not surprising on theoretical

Generalization in pollination systems, and why it matters

The term phenology is derived from the Greek word phaino meaning to show or to appear. Hence, phenology is defined as the study of the seasonal timing of life cycle events. For plants the seasonal timing of such events can be critical to survival and reproduction. In agriculture the most common failure of introduced crops is the inability to adjust to the seasons imposed by the new, environment (68). In the past few years, interest in the ecology and evolution of timing of life cycle events has grown. Here we review the literature on phenological patterns of germination, flowering, and fruiting (including dispersal).

/pdf/phenological-patterns-of-terrestrial-plants-2339nfk6dp.pdf

Phenological Patterns of Terrestrial Plants

Understanding the roles of age and size in the timing of first reproduction or flowering in plants has become a goal for those investigating the evolution of life cycle patterns in general. Here I review the studies that are helping to clarify these roles, and indicate some directions for future research.

/pdf/onset-of-reproduction-in-plants-size-versus-age-dependency-2co4x7ekar.pdf

Onset of reproduction in plants: size-versus age-dependency

A reciprocal transplant experiment was conducted to examine several aspects of life-history variation in Daucus carota along its latitudinal range in eastern North Amer- ica. Seeds collected from natural populations at 36", 42", and 45" N were sown onto plots at each of the three latitudes. Marked seedlings were followed for 3 yr to examine (1) genetic and environmental components of variation in growth, survival, and year of re- production; (2) size and age at time of reproduction; and (3) the roles that density- and age-dependent selection may play in producing the variation in age of reproduction. Mean age of reproduction increased clinally from south to north but showed no pattern of variation among different-aged populations within the same latitude. The clinal variation has likely arisen since the introduction of D. carota into North America in the 17th century and has developed independently of any role that growth rate plays in determining age of reproduction. Density influences age of reproduction both directly and indirectly by af- fecting plant size. Age-specific survival varied strongly over plot latitude but not among populations planted in the same latitude. The ratio of percent germination and survival of 1-yr-olds to percent survival of 2-yr-olds was - 3:1, 0.2: 1, and 0.15: 1 for plots at 36O, 42", and 45" N, respectively. The experiment suggests that latitudinal variation in age-specific mortality patterns is helping to maintain clinal variation in age of reproduction. Density-independent factors contribute more strongly to age-specific mortality than do density-dependent factors. Age classes are based on times of peak flowering rather than on times of growing seasons. Such intervals allow for better evolutionary interpretation of demographic data.

https://www.jstor.org/stable/pdfplus/1943178.pdf

Latitudinal variation in reproductive timing of a short-lived monocarp, daucus carota (apiaceae)

In spite of the potential evolutionary importance of parental effects, many aspects of these effects remain inadequately explained. This paper explores both their causes and potential consequences for the evolution of life-history traits in plants. In a growth chamber experiment, I manipulated the pre- and postzygotic temperatures of both parents of controlled crosses of Plantago lanceolata. All offspring traits were affected by parental temperature. On average, low parental temperature increased seed weight, reduced germination and offspring growth rate, and accelerated onset of reproduction by 7%, 50%, 5%, and 47%, respectively, when compared to the effects of high parental temperature. Both pre- and postzygotic parental temperatures (i.e., prior to fertilization vs. during fertilization and seed set, respectively) influenced offspring traits but not always in the same direction. In all cases, however, the postzygotic effect was stronger. The prezygotic effects were more often transmitted paternally than maternally. Growth and onset of reproduction were influenced both directly by parental temperature as well as indirectly via the effects of parental temperature on seed weight and germination. Significant interactions between parental genotypes and prezygotic temperature treatment (G × E interactions) show that genotypes differ in their intergenerational responses to temperature with respect to germination and growth. The data suggest that temperature is involved in both genetically based and environmentally induced parental effects and that parental temperature may accelerate the rate of evolutionary change in flowering time in natural populations of P. lanceolata. The environmentally induced temperature effects, as mediated through G × (prezygotic) E interactions are not likely to affect the rate or direction of evolutionary change in the traits examined because postzygotic temperature effects greatly exceed prezygotic effects.

https://www.jstor.org/stable/pdfplus/2410858.pdf

Parental effects in plantago lanceolata l. i.: a growth chamber experiment to examine pre- and postzygotic temperature effects.

Biologists working in fields as diverse as mammalian behavior, plant ecology, microbial genetics, quantitative genetics, and insect ecology have shown that environmentally induced parental effects can be found in most kingdoms of living organisms. Such effects are diverse, have multiple causes, and can be transmitted via multiple pathways. Historically, and understandably, these effects have been studied by biologists who have focused on a particular group of organisms, such as insects or plants, or who have approached the phenomenon from a particular point of view, such as quantitative genetics, ecology, or behavior. The consequence has been the development of multiple terminologies that are not used consistently across disciplines or kingdoms. I believe these inconsistencies hinder the communication among biologists studying these effects, the development of generalized models of parental effects, and the empirical testing of adaptedness of these effects.

Elizabeth P. Lacey

Papers

Phenological Patterns of Terrestrial Plants

Onset of reproduction in plants: size-versus age-dependency

Latitudinal variation in reproductive timing of a short-lived monocarp, daucus carota (apiaceae)

Parental effects in plantago lanceolata l. i.: a growth chamber experiment to examine pre- and postzygotic temperature effects.

What Is an Adaptive Environmentally Induced Parental Effect