Riedl's related concept, evolvability, refers to the probability that a new trait arising from mutation will be viable (Wagner and Laubichler 2004).
Not important in evolutionary change Origin of new traits Arise in an undirected fashion by random mutation.
Given the way that genetic mutations are often portrayed in science fiction and popular culture, students are more likely to state that new traits arise as a result of an organism's needs or in response to environmental changes rather than occurring through random genetic processes (Bishop and Anderson 1990; Dagher and Boujaoude 2005; Geraedts and Boersma 2006; Shtulman 2006).
Thus, clarifying how the environment influences the expression and evolution of complex traits is crucial for understanding how new traits arise.
A new behavioural trait arises in (or is invented by) an ill individual who may then demonstrate this practice; others who are ill may adopt the practice upon being exposed to it, and then become demonstrators themselves.
This idea is captured in the expression "teaching old genes new tricks" [ 3], used to explain the genetic mechanisms through which novel traits arise.
Dramatic examples of entirely new, unique traits arising through mutation have been observed in recent years, such as the evolution of nylon-eating bacteria, which developed new enzymes to efficiently digest a material that never existed before the modern era.
Many hypotheses for signal evolution postulate that new call traits arise and are stabilized through female preferences, either as a result of coevolutionary processes involving the male call and female preference [7] [9], or through receiver biases in the sensory system of females [10], [11].
Although a great deal has been learned regarding the genetic changes that give rise to adaptation in bacteria and yeast, an understanding of how new complex traits arise in multicellular organisms is far less complete.
In that sense, students are challenged to think about new traits as arising due to multiple, random genetic processes, such as recombination of genes through sexual reproduction, gene shuffling and random mutations in genetic sequences (Garvin-Doxas and Klymkowsky 2008).
