Thus, the PC1 confirmed the significant QTL on chromosome 5 found with the daily body weight loss traits.
This could also suggest that sex-specific evolution in the P- vs. the M-regime has selected for different reproductive traits or loss of traits leading to different reproduction-survival trade-offs in response to food quality [ 53].
The molecular mechanisms for the emergence of novel traits and, more dramatically, the loss of traits that were thought to be essential is currently a hot topic (Johnson and Tsutsui 2006; Rebeiz et al. 2011; Star et al. 2011).
To date, this has proved true for loss of traits in fish: armor plates, pelvic fins and pigment.
For both gain and loss skeletal traits, our genetic studies have revealed that both similar (Glazer et al., 2014; Erickson et al., 2014) and distinct (Ellis et al., 2015; Glazer et al., 2015) genetic architectures can underlie convergent adaptive evolution.
Loss of traits that originally evolved due to sexual selection is a common phenomenon (Wiens 2001).
The ACORNS is designed with a sixteen item scoring rubric that standardizes student responses that differ across contextual variables for evolution (e.g., gain vs. loss of traits, plants vs. animals, within vs. between species differences).
This progressive loss of traits could be caused either by T substitutions or T deletions as discussed earlier.
Also, many of the reported evolutionary changes represent de-domestication, the evolutionary loss of traits accumulated under domestication (Gressel 2005a).
Alternatively, we could hypothesize that endophyte lineages may have evolved over time as commensals, for example, as a result of the loss of traits that confer pathogenicity.
