A woman's genes are much more likely than lifestyle factors such as stress or diet to cause greying hair, a study suggests. Unilever scientists studied more than 200 identical and non-identical Danish twin sisters aged between 59 and 81.

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They're both pediatricians, and for years, the two men were well regarded professionals with successful practices. The brothers also lived together and neither one was married.

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A Trip to the Zoo

It has taken me almost four years to finally put these thoughts to paper (or electronic media, you understand the metaphor). It is, without question, the most transformative episode of my life and still to this day haunts me.

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Our level of happiness throughout life is strongly influenced by the genes with which we were born, say experts. An Edinburgh University study of identical and non-identical twins suggests genes may control half the personality traits keeping us happy.

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The journal Science has published its choice for the most important scientific breakthrough of 2007. It's about you, me, and everyone else on the planet. This is the year in which technology made it much faster and easier to scan through large portions of an individual's genome.

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Paula Bernstein and Elyse Schein lived very similar lives. They were both born in New York, edited their high school newspapers and studied film at university. And both were adopted in 1968.

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Here is one pair of twin brothers that few will have any difficulty telling apart. For although Byron and Lincoln Ryman were born within a minute of each other, firstborn Byron - at 3lb 6oz a small baby himself - was precisely three times bigger than his sibling.

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I'm not sure any hockey executive has ever made a roster move purely to appease us media types, and yet thanks are still in order to Dallas GM Doug Armstrong, who called up center Joel Lundqvist from Iowa just in time to face his twin brother Henrik tonight in Dallas.

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