The model showed that a partial pressure of only 2.9 millibars of co 2 would have been needed during the late archaean and early proterozoic periods in order to bring the surface temperature of the earth above freezing .
An archaean converts dna into proteins very differently from , say , streptococcus-in fact , protein synthesis in archaea is more similar to the human process than to bacteria .
He says by examining oxidation rates they have shown the mantle has cooled several hundred degrees since the archaean .
丹尤柴夫斯基说,通过检测氧化的速度,他们证明了自从太古代以来,地幔冷却了好几百度。
A study published this month in environmental microbiology describes a " giant " archaean that grows to 3 centimeters long and is nearly visible without magnification ( it 's just 0.1 mm thick ) .