A global assessment of declining cacti populations places responsibility on increasing human activities.
Researchers have discovered a conserved mechanism among vertebrates that determines body segment number, according to a study published online in Nature today (June 18). The number of body segments an organism has varies greatly between species: our vertebrae, a measly thirty-three in number, hardly stack up to the 300-plus in our slithering co-vertebrates. But anatomists and embryologists have puzzled over a mechanism to explain the difference. "If you were to ask most biologists w
June 18, 2008|
June 18, 2008