Test for teenage boys' depression. 18th February 2014 --Teenage boys with symptoms of depression who also have raised levels of the stress hormone cortisol are up to 14 times more likely to develop major depression than those without.
Rating Newest Oldest. Best Answer: Most scientists believe that the first life forms were evolved in oceans that were BGA(blue green algae). Many believe that with these algae a simple organism named cyano bacteria was also evolved. Source(s): Shivansh Â· 5 years ago.
The modern-day organisms that seem oldest, in an evolutionary sense, are microbes that. live in the hot water around volcanic vents on the ocean floor. Nearly all of the oxygen in the Earth's atmosphere was originally produced by photosynthesis in the leaves of trees that covered the continents 3.5 billion years ago. The requirement of liquid water is the most severe constraint on the development of life.