Earth formed around 4.54 billion years ago by accretion from the solar nebula. Volcanic outgassing probably created the primordial atmosphere and then the ocean; but the atmosphere contained almost no oxygen and so would have been toxic to most modern life including humans.
Euthyroid is the state of having normal thyroid gland function. Examples of a nonfunctioning thyroid gland may be hypothyroidism, hyperthyroidism, or thyroiditis.
euÂ·stele. 1  the typical vascular cylinder of a dicotyledonous plant or a gymnosperm, consisting of a ring of collateral bundles of xylem, cambium, and phloem. 2  A stele in which the primary vascular tissue is arranged in bundles around a pith, as in most seed plants.