Daisy gives an evolutionary answer

Article Abstract:

Species of the daisy family Asteraceae on Canadian islands were examined to study the loss of dispersal ability by plants and animals confined to islands. The diaspore, the dispersal unit of these daisies, is composed of a tiny seed surrounded by a larger ball of fluff. It thus resembles a parachute that is suitable to being carried by the wind. The diaspore is likely to be carried farther and to stay loft longer as its fluff ball gets bigger and the seed lighter. The study conducted by Martin Cody and Jacob Overton is a direct observation of rapid evolutionary change and the 'founder effect' in wild plant populations.

Evolution (Biology), Evolution, Plant population genetics, Daisies

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Competition for brain space

Article Abstract:

Natural selection eliminates the deleterious mutations of gene coding for structures that are active and retains them if the structure falls in the category of disuse. Blind mole rats belonging to genus Spalax posses reduced eyes because they spend most of their lives in the dark. The visual system atrophy is highly selective in this species as the eye structures associated with image formation are reduced but the suprachiasmatic nucleus responsible for photoperiodism and reception of diffused light remain active.

Analysis, Observations, Atrophy, Blind mole rats, Animal mutation

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Australia's last giants

Article Abstract:

Extinction of the very large animals that once roamed across Australia took places within a short time across the range of the country's habitats, longitudes, latitudes, megafaunal species and climate regions. The extinctions arose during a phase of benign moist climate 25,000 years prior to the country's arid phase at the Last Glacial Maximum.

Australia, Paleontology, Extinction (Biology)

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