Life began on earth and in the oceans long before humans ever existed. Science has proven that life may have begun in the oceans and eventually evolved and moved to life on land. Understanding the origin of life in the ocean and how it moved to land is significant to understanding life as it began and evolved across the earth.
One theory on how life began on the ocean is through comets and meteors. The answer dipeptides, which as Robert Sanders explains “are essential building blocks shared by all living things” (2013). Dipeptides are linked pairs of amino acid and a recent experiment conducted by the University of California Berkley shows that such amino acids could have been created in outer space and carried to earth via comets or potentially even meteorites. These dipeptides and amino acids have the ability to “catalyze biological evolution on earth” (Sanders 2013), or life. Comets that crashed into the ocean would have delivered the complex molecules necessary for the growth of complex proteins and sugars required for the creation of life.
Life originated in the oceans; however, eventually moved to land. Why it did not begin on land may be difficult to understand; however, the answer lies in one of the most essential elements to life on land and the complex organisms that exist today: oxygen. Originally, oxygen, which is abundant in modern Earth’s air, was not always present in the quantities necessary to sustain life on land. Original life within earth’s oceans “evolved [to be able to] use carbon dioxide, along with solar radiation, to produce energy and oxygen—a process called photosynthesis” (“Marine organisms produce…” n.d.). Once these original organisms produced enough oxygen to sustain complex life on land, evolution allowed for the diversity of land-dwelling creatures that relied on oxygen to live.
Life on earth has come a long way from the hundreds of millions of years ago when comets first introduced amino acids into the earth’s oceans, providing the catalyst for life as we know it today. Life on earth would have been impossible without the thousands of years of evolution which took life on earth from simple, ocean-dwelling organisms to the complex creatures that exist today both on land and in the oceans.
- Marine organisms produced over half of the oxygen that land animals need to breathe. Retrieved from http://oceanexplorer.noaa.gov/facts/oceanproduction.html
- Sanderes, Robert. (March 5, 2013). Evidence that comets could have seeded life on Earth. Retrieved from http://newscenter.berkeley.edu/2013/03/05/research-news-briefs-did- comets-seed-life-on-earth/