What change caused multicellular life to form?
Answers
Scientists are discovering ways in which single cells might have evolved traits that entrenched them into group behavior, paving the way for multicellular life. These discoveries could shed light on how complex extraterrestrial life might evolve on alien worlds.
Researchers detailed these findings in the Oct. 24 issue of the journal Science.
The first known single-celled organisms appeared on Earth about 3.5 billion years ago, roughly a billion years after Earth formed. More complex forms of life took longer to evolve, with the first multicellular animals not appearing until about 600 million years ago.
The evolution of multicellular life from simpler, unicellular microbes was a pivotal moment in the history of biology on Earth and has drastically reshaped the planet’s ecology. However, one mystery about multicellular organisms is why cells did not return back to single-celled life.
Answer:
An ice age caused Earth’s oceans to cool, which killed many of the unicellular organisms. When the ice age ended and Earth warmed, the continents broke apart. This event allowed the shallow seas to cover the continents. The warming of Earth, accompanied by the seas covering the land, created the proper conditions for multicellular organisms to form.
Explanation: