Reproductive behavior of female buntings: Isolating mechanisms
in a hybridizing pair of species.
Most critical to this study, the knowledge and the access to knowledge sources embedded in these inter-organizational assets may serve as an isolating mechanism.
Together, these arguments support the view that contractual alliances with strategic partners may serve as an isolating mechanism and therefore enhance the prospect of sustained IPO success.
3) The Trust created a new strategic isolating mechanism and new institutional rules of play, since access to film stock and equipment now required membership in or licensing by the Trust.
The Trust's strategic isolating mechanism of pooling their patents was ruled an illegitimate form of competition and new institutional rules of play were invoked by Court order.
Thus, the effect of differential pollen-tube growth on hybridization frequency that we have demonstrated with controlled crosses has the opportunity to act as a heterospecific isolating mechanism
Although the importance of reproductive isolation in the formation and maintenance of species has been widely accepted (Mayr 1942; Dobzhansky 1951; Littlejohn 1981; Futuyma 1986; Endler 1989; Ridley 1993; but see Paterson 1985), elucidating the genetics and transformation of specific reproductive isolating mechanisms
remains a formidable challenge for evolutionary biologists (Coyne and Orr 1989a,b; Endler 1989; Coyne 1993).
Given these conditions, the likely premating isolating mechanism
remains the timing differences in cercarial shedding, diurnal for S.
Besides the original definition, Dobzhansky's major contribution to this notion is his classification of the biological factors preventing hybridization, the so-called "reproductive isolating mechanisms
," and their division into categories acting before (prezygotic) and after (postzygotic) fertilization.
In a 50-minute lecture period I introduce species concepts (at least the biological and morphological species concepts), the reproductive isolating mechanisms
that keep species distinct, and modes of speciation (allopatric and sympatric).
This ignores the fact that Mayr discussed a variety of other isolating mechanisms
besides allopathic speciation.
An explanation for this pattern may lie in the relative strength of prepollination and postpollination isolating mechanisms