Sunday, October 21, 2007

Oxygen Was Toxic To Life

Current living things require oxygen to live. It was not always like this. As a matter of fact, oxygen was downright poisonous to life and nearly destroyed all life on Earth.

The most readable account of this event can be found here. Around 2.4-2.5 billion years ago, global cooling almost turned Earth into an ice ball, destroying all life then.

Luckily, the Earth didn't turn into an ice ball, and some organisms adapted to use oxygen in energy production. In fact, every animal and plants descends from single cell ancestors that captured those oxygen-adapted organisms. Right now, all our cells (except sperm cells) contain those organisms in the form of mitochondria. We inherit mitochondria from our mother, not from our father.

1 comment:

joey said...