https://en.wikipedia.org/wiki/Evolutionary_history_of_life

The evolutionary history of life on Earth traces the processes by which living and fossil ..... Evidence suggests the first RNA molecules formed on Earth prior to 4.17 Ga. Although ..... All animals are motile, if only at certain life stages. All animals ...

https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_history_of_life

This timeline of the evolutionary history of life represents the current scientific theory outlining ... The first known mass extinction in earth's history was the Great Oxygenation Event 2.4 billion years ago. That event led to the loss ..... This innovation causes a major burst of animal evolution through coevolution. First freshwater ...

http://naturalhistory.si.edu/education/teaching-resources/life-science/early-life-earth-animal-origins

Learn what fossil evidence reveals about the origins of the first life on Earth, from bacteria to animals, including the phyla we know today.

https://www.livescience.com/4880-shock-animal-earth-surprisingly-complex.html

Apr 9, 2008 ... New study shows complex creature was likely Earth's first animal. ... genetic data to define the earliest splits at the base of the animal tree of life.

https://www.newscientist.com/article/dn17453-timeline-the-evolution-of-life/

Jul 14, 2009 ... There are all sorts of ways to reconstruct the history of life on Earth. Pinning .... It seems likely that the first bilateral animal was a kind of worm.

https://www.livescience.com/57942-what-was-first-life-on-earth.html

Mar 1, 2017 ... The earliest evidence for life on Earth arises among the oldest rocks still preserved on the planet. Earth is about 4.5 billion years old, but the ...

https://www.bbvaopenmind.com/en/science/bioscience/what-were-the-first-animals-on-earth/

Nov 5, 2018 ... For some four billion years, no life existed on Earth more complex than a simple cell. Then, and for reasons still unknown, about 575 million ...

https://www.washingtonpost.com/news/speaking-of-science/wp/2017/08/17/the-first-animals-evolved-during-the-absolute-worst-time-on-earth/

Aug 17, 2017 ... New research aims to explain how complex life emerged during a period when Earth was ravaged by ice and roasted by volcanoes.

https://www.physicsoftheuniverse.com/topics_life.html

The study of the origin of life on Earth or, more specifically, how life on Earth ... is the study of how living things have changed over time since life first arose).

https://www.independent.co.uk/news/science/first-animals-appear-earth-mystery-solved-scientists-snowball-bacteria-a7896641.html

Aug 16, 2017 ... New research has shed fresh light on how animals first appeared on the ... Life on Earth was dominated by simple bacteria up until about 650 ...