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D W Pfennig

Publications and source records attributed to D W Pfennig.

3 recordsLinked to original sources

Kin recognition.

Many organisms, from sea squirts to primates, can identify their relatives. Understanding how and why they do so has prompted new thinking about the evolution of social behavior.

Animals

Kinship affects morphogenesis in cannibalistic salamanders.

Inclusive fitness theory predicts that organisms can often increase their fitness by helping relatives. Indeed, many animals modify their behaviour towards kin in a fashion consistent with theory. Morphogenesis may also be sensitive to kinship environment, especially in species that facultatively produce distinct morphs that differ in their ability to harm relatives, such as those that produce alternative cannibalistic and non-cannibalistic phenotypes. We tested this hypothesis by examining whether consanguinity affected the probability that structurally distinctive cannibal morphs would develop in larval Arizona tiger salamanders (Ambystoma tigrinum nebulosum). We report here that when tiger salamander larvae are reared in mixed-brood groups they are significantly more likely to develop the cannibal morphology and at an earlier age than siblings reared in pure-sibship groups. In general, morphogenesis may be responsive to kinship in any species that facultatively develops structures that can be used against conspecifics as weaponry.

Animals

Inbreeding and reproductive performance in standardbred horses.

The relationship between inbreeding and both conception and foaling rates in Standardbred horses (trotters and pacers) was examined for 1194 breeding years. There was a statistically significant (P less than 0.05) trend for conception and foaling rates to decrease with increased inbreeding; however, this relationship accounted for less than 2 percent of the variation. Additionally, the relationship between reproductive performance and inbreeding was not consistent between trotters and pacers. For trotters (F = 0.103) there was a trend for an increase in conception and foaling rates with increased inbreeding, while for pacers (F = 0.074), reproductive performance decreased with increased inbreeding. Overall, inbreeding does not appear to be a significant factor influencing reproductive performance of Standardbred horses.

Animals