de Queiroz (1995), Griffiths (1999) and LaPorte (2004) offer a new version of essentialism called "historical essentialism". According to this version of essentialism, relations of common ancestry are essential features of biological taxa. The main type of argument for this essentialism proposed by Griffiths (1999) and LaPorte (2004) is that the dominant school of classification, cladism, defines biological taxa in terms of common ancestry. The goal of this paper is to show that this argument for historical essentialism is unsatisfactory: cladism (...) does not assume that relations of common ancestry are essential attributes of biological taxa. Therefore, historical essentialism is not justified by cladism. (shrink)

Cooperative behaviors within a group face the risk of being exploited by `free-riders,' individuals that reap the benefits produced by cooperators without paying the costs of cooperating. Free-riders are often perceived as a burden to the group, since the group's survival depends on tasks performed by cooperators. However, this paper challenges this perspective, arguing that an excess of cooperators may actually lower the efficiency and persistence of groups. The perspective presented in this paper has ramifications to broader issues in philosophy, (...) particularly the challenge of how to balance self-interest with the collective interests of the group. Ultimately, this paper seeks to highlight some of the subtle ways free-riders positively impact their groups, an aspect of free-riding that is often overlooked in discussions about cooperation. (shrink)