Global Climate Change: The Impact Of El Niño On Galápagos Marine Iguanas:
A before-and-after study led by Yale biologists, of the effects of 1997 El Niño on the genetic diversity of marine iguanas on the Galápagos Islands, emphasizes the importance of studying populations over time and the need to determine which environmental and biological factors make specific populations more vulnerable than others.
Evolution With A Restricted Number Of Genes:
The development of higher forms of life would appear to have been influenced by RNA polymerase II. This enzyme transcribes the information coded by genes from DNA into messenger-RNA (mRNA), which in turn is the basis for the production of proteins. RNA polymerase II is highly conserved through evolution, with many of its structural characteristics being conserved between bacteria and humans.
Wild Chimpanzees Appear Not To Regularly Experience Menopause:
A pioneering study of wild chimpanzees has found that these close human relatives do not routinely experience menopause, rebutting previous studies of captive individuals which had postulated that female chimpanzees reach reproductive senescence at 35 to 40 years of age.
How Plants Control The Size of Leaves and Flowers:
The beauty of nature is partly due to the uniformity of leaf and flower size in individual plants, and scientists have discovered how plants arrive at these aesthetic proportions. Researchers at the John Innes Centre in Norwich have discovered that cells at the margins of leaves and petals play a particularly important role in setting their size.
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