Search results
Results from the WOW.Com Content Network
v. t. e. In evolutionary biology, punctuated equilibrium (also called punctuated equilibria) is a theory that proposes that once a species appears in the fossil record, the population will become stable, showing little evolutionary change for most of its geological history. [1] This state of little or no morphological change is called stasis.
Group development. The goal of most research on group development is to learn why and how small groups change over time. To quality of the output produced by a group, the type and frequency of its activities, its cohesiveness, the existence of group conflict. A number of theoretical models have been developed to explain how certain groups ...
Punctuated equilibrium in social theory is a conceptual framework for understanding the process of change in complex social systems. The approach studies the evolution of policy change, [1] including the evolution of conflicts. [2] The theory posits that most social systems exist in an extended period of stasis, which may be punctuated by ...
The equilibrium model of group development (equilibrium model) is a sociological theory on how people behave in groups. The model theorizes that group members will work to maintain a balance, or equilibrium, between task-oriented (instrumental) and socio-emotional (expressive) needs. [1][2] A group can be successful if it maintains this ...
Gould's initial work on punctuated equilibrium was coauthored with Niles Eldredge. [20] Gould's model of punctuated equilibrium drew attention to episodic bursts of evolutionary change followed by periods of morphological stability. He challenged the conventional model of gradual, continuous change - called phyletic gradualism. [21]
Punctuated equilibrium and phyletic gradualism are not mutually exclusive (as Simpson's work demonstrates), and examples of each have been documented in different lineages. The debate between these two models is often misunderstood by non-scientists, and according to Richard Dawkins has been oversold by the media. [ 45 ]
Punctuated gradualism is considered to be a variation of these models, lying somewhere in between the phyletic gradualism model and the punctuated equilibrium model. It states that speciation is not needed for a lineage to rapidly evolve from one equilibrium to another but may show rapid transitions between long-stable states.
The Extended Evolutionary Synthesis (EES) consists of a set of theoretical concepts argued to be more comprehensive than the earlier modern synthesis of evolutionary biology that took place between 1918 and 1942. The extended evolutionary synthesis was called for in the 1950s by C. H. Waddington, argued for on the basis of punctuated ...