Search results for "evolutionary change"

Processus écologiques et évolutifs influençant la colonisation de l'ambroisie à feuilles d'armoise (Ambrosia artemisiifolia l.) en France.

2012

Understanding of the mechanisms behind the success of the invasive species is essential to manage current biological invasions and to prevent the risks of the futures ones. Using a conceptual framework integrating ecological and evolutionary processes, this work aimed to analyse the factors of the common ragweed colonization in France. First of all, the study of biotic and abiotic interactions has shown the ability of common ragweed to tolerate herbivory and water stress. Common ragweed is able to buffer defoliation through an efficient compensatory growth with no consequence on the reproduction. Herbivory tolerance has been maintained in introduced populations even if herbivory pressure is…

Mate fidelity and coloniality in waterbirds: a comparative analysis

1998

Increased opportunities for information are one potential benefit of sociality. We apply this idea to the advantages of colonial breeding in bird species that are typically monogamous within a breeding season but often form new pair-bonds in subsequent seasons. Individuals may benefit from nesting in colonies at high density by identifying good-quality potential alternative mates among their neighbours. The opportunities for finding a better mating option are likely to increase with colony size and density. We tested this prediction with a comparative analysis of the association between mate fidelity and coloniality in waterbirds (wading birds and seabirds), where there is wide variation in…

Toward a mechanistic understanding of vulnerability to hook-and-line fishing: Boldness as the basic target of angling-induced selection

2017

In passively operated fishing gear, boldness-related behaviors should fundamentally affect the vulnerability of individual fish and thus be under fisheries selection. To test this hypothesis, we used juvenile common-garden reared carp (Cyprinus carpio) within a narrow size-range to investigate the mechanistic basis of behavioral selection caused by angling. We focused on one key personality trait (i.e., boldness), measured in groups within ponds, two morphological traits (body-shape and head-shape), and one life-history trait (juvenile growth capacity) and studied mean standardized selection gradients caused by angling. Carp behavior was highly repeatable within ponds. In the short-term, ov…

Marine food web perspective to fisheries‐induced evolution

2021

Abstract Fisheries exploitation can cause genetic changes in heritable traits of targeted stocks. The direction of selective pressure forced by harvest acts typically in reverse to natural selection and selects for explicit life histories, usually for younger and smaller spawners with deprived spawning potential. While the consequences that such selection might have on the population dynamics of a single species are well emphasized, we are just beginning to perceive the variety and severity of its propagating effects within the entire marine food webs and ecosystems. Here, we highlight the potential pathways in which fisheries‐induced evolution, driven by size‐selective fishing, might reson…

The multiple directions of evolutionary change.

2008

The theory of Punctuated Equilibria challenges the neo-Darwinian tenet that evolution is a uniform process. Recently, an article by Hunt1 has found that directional change during the evolution of a lineage is relatively small (occurring only in 5% of 250 analyzed traits). Of those traits that were shown to follow a trend, size was more likely to show gradual changes, whereas shape changes were more random. Here, we provide a short view of the nature of evolutionary trends, showing that directional change within lineages and among clades provides valuable evolutionary information about the processes involved in their generation. BioEssays 30:521–525, 2008. © 2008 Wiley Periodicals, Inc.

1993

Biology tells us about the processes and mechanisms which are able to explain effectively the changes occurring in organisms and species. Palaeontology, with the temporal dimension at its disposal, adds to this data which are indispensable for our understanding of speciation and of the patterns and rhythms of evolutionary change. Only through this we are able to observe the historical development of the evolution, of the living world as it took place through geological time. Based on data obtained from other branches of the earth sciences, palaeontology is able to evaluate the external constraints which frequently act at random on the living organism and which control the formation of new s…

Marine food web perspective to fisheries-induced evolution

2021

Fisheries exploitation can cause genetic changes in heritable traits of targeted stocks. The direction of selective pressure forced by harvest acts typically in reverse to natural selection and selects for explicit life-histories, usually for younger and smaller spawners with deprived spawning potential. While the consequences that such selection might have on the populational dynamics of a single species are well emphasised, we are just beginning to perceive the variety and severity of its propagating effects within the entire marine food webs and ecosystems. Here, we highlight the potential pathways in which fishing-induced evolution, driven by size-selective fishing, might resonate throu…

1993

Genetics and developmental genetics have given us such a wealth of new insight that, at the end of this century, the synthetic theory can no longer be maintained in the strict “orthodox” sense in which it was started.

1993

The genetic material containts the instructions necessary for the construction of an organism and ensures the continuity of the species by transmission of the construction plan from generation to generation over considerable periods of time.

The enigma of frequency-dependent selection

1997

Frequency-dependent selection is so fundamental to modern evolutionary thinking that everyone interested in evolutionary biology 'knows' the concept. It is even so fundamental that many authors of textbooks do not bother to define it. Yet it turns out that different authors (and sometimes even one and the same author) use the term to refer to different types of selection. In this paper we try to uncover the sources of this confusion. The concept is fairly well defined in the original concept of population genetical theory, which focuses on short-term evolutionary change, and basically ignores density-dependence. The problems start when the original concept is used in the context of long-ter…