Evolution and systematics

The subclass Merostomata is one of three branches of the chelicerate line of arthropods; the other two branches include sea spiders and terrestrial spiders. Thus horseshoe crabs are more closely related to spiders and scorpions than to other crabs. Horseshoe crabs date to the Carboniferous period (350 million years ago [mya]). Ancestral relatives from the Cambrian period (550 mya) have been found. Horseshoe crabs are classified into a single order (Xiphosura) and family (Limul-idae). Four species are recognized. Many scientists now categorize Merostomata as a class rather than a subclass.

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Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

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