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A Bug’s (Sex) Life: Diving Beetles Offer Clues About Sexual Selection

By Guest PostFebruary 6, 2012Nature, Sciencearizona desert, co evolution, dawn higginson, diving beetles, dytiscidae, epifluorescence image, Europe, evolution, evolutionary relationship, female, fertilization, great diving beetle, hygrotus sayi, invertebrate, kari segraves, kelly miller, larva, male, mammal, mollusk, reproductive organ, scott pitnick, sexual evolution, sexual selection, sexual trait, speciation, sperm evolution, sperm storage, spermatheca, syracuse university, thermonectus marmoratus, university of arizona

*Studies of diving beetles suggest sperm evolution may be driven by changes in female reproductive organs, challenging the paradigm of post-mating sexual selection being driven mostly by competition among sperm.*

Studying female reproductive tracts and sperm in diving beetles (Dytiscidae), researchers from the University of Arizona and Syracuse University have obtained a glimpse into a bizarre and amazing world of sperm that can take on a variety of forms – including joining together into conglomerates that navigate the twisted mazes of the female reproductive tract.

Analyses of the evolutionary relationships among diving beetles reveal that sperm form appears to follow function dictated by female reproductive organs. (more…)

What’s so Unique About the Tropics?

By Guest PostSeptember 23, 2011Environment, Sciencebeta diversity, brad boyle, calgary, canada, costa rica, distribution of biodiversity across the globe, ecological mechanisms, ecologists, elevations in mountain regions, extinctions, geographical scales, latitudinal diversity gradient, nathan j b kraft, new zealand, northern europe, panama, south america, speciation, temperate forests of canada, tropical rainforests of southeast asia, tropics, university of arizona ecologist, university of british columbia, university of maryland

“Less than we thought,” researchers say in a new study providing insights into the distribution of biodiversity across the globe.

The temperate forests of Canada or Northern Europe may have much more in common with the tropical rainforests of Southeast Asia or South America than previously believed, according to a research group including a University of Arizona ecologist.

The assertion, published as the cover article in the journal Science, is focused on the concept of “beta-diversity” – a measure of the change in species composition between two sites, such as neighboring patches of forest. High beta-diversity means that two given sites have few species in common. (more…)

Tag Archives: speciation

A Bug’s (Sex) Life: Diving Beetles Offer Clues About Sexual Selection

What’s so Unique About the Tropics?