scholarly journals The evolutionary significance of long copulation duration in bumble bees

Apidologie ◽  
2005 ◽  
Vol 36 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Mark J.F. Brown ◽  
Boris Baer
1973 ◽  
Vol 105 (5) ◽  
pp. 733-743 ◽  
Author(s):  
R. C. Plowright ◽  
W. P. Stephen

AbstractThe question of whether the evolutionary origin of the parasitic bumble bees (Psithyrus Lep.) was monophyletic or polyphyletic has not been convincingly resolved by conventional systematics. In this study numerical taxonomic (NT) analysis was applied to data on wing venation from a set of 13 species of Psithyrus and 60 species of non-parasitic bumble bees (Bombus Latr.), representing 16 of the subgeneric divisions recognized by Richards. The resultant cluster analysis gave an almost perfect grouping of the constituent Bombus species into their ’correct’ subgenera. This was taken as evidence that the NT procedure had yielded discriminant criteria of evolutionary significance. Since the same criteria also produced a single grouping of the Psithyrus species, the results support a monophyletic origin for Psithyrus.


Author(s):  
Francisco J. Ayala ◽  
Camilo J. Cela-Conde

This chapter analyzes the transition of the hominins from the Middle Pleistocene to the Late Pleistocene. Two alternative models are explored, the “Multiregional Hypothesis” (MH) and the “Replacement Hypothesis,” and how each model evaluates the existing relationships between the taxa Homo neanderthalensis and Homo sapiens. Next is the investigation of the transitional (or “archaic,” if this grade is taken into account) exemplars found in Europe, Africa, and Asia and their evolutionary significance. In particular, the comparison between H. erectus and H. sapiens in China and Java is investigated, as the main foundation of the MH. The chapter ends with the surprising discovery of Homo floresiensis and its description and interpretations concerning its taxonomic and phylogenetic significance. The correlation between brain development and technological progress is at odds with the attribution of perforators, microblades, and fishing hooks to a hominin with a small cranial volume, similar to that of Australopithecus afarensis.


2009 ◽  
Vol 51 (2) ◽  
pp. 226-246 ◽  
Author(s):  
Alan F. Hofmann ◽  
Lee R. Hagey ◽  
Matthew D. Krasowski

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