Scientists report evidence that life on Earth originated 1.5 billion years earlier than was previously estimated. We are examining the leading theories on how life first emerged.
For centuries, humans have pondered the origins of life on Earth, the essence of existence — in essence, our point of origin and our ultimate destiny.
It’s a question that intersects multiple fundamental fields, including chemistry, biology, and physics, as well as philosophy, psychology, and components of faith. Initially, scholars contributed to all areas of investigation. Nevertheless, the core sciences are generally viewed as more precise and quantifiable, making them a primary focus for scientists today.
In the 19th century, French chemist Louis Pasteur demonstrated that life originates only from life. Plants, animals, and microbes multiply within their respective species.
What about the origin of the original life form? At what stage, and through what process, did it emerge from inanimate matter?
New discoveries suggest that life might date back centuries or even millennia, contrary to previous theories that it emerged thousands of years ago.
A study conducted by researchers from Cardiff University in Wales, UK, proposes that life on Earth may have been more complex than previously believed, potentially dating back 2.3 billion years. The team reportedly discovered signs in rocks from Gabon that suggest a hospitable environment for life 2.1 billion years ago.
The research indicates that a collision between two continental plates greater than 2 billion years ago produced an environment rich in nutrients, which enabled the evolution of sophisticated organisms.
That would have generated phosphorus and necessary atmospheric oxygen for the transformation of unicellular organisms into more complex forms of life.
Despite their complexity, these lifeforms had a short-lived existence, seemingly confined to a regional environment and unable to inhabit the entire globe.
This research questions a widely accepted scientific theory that animal life emerged 635 million years ago, and proposes that there was a first, unsuccessful effort at complex life on Earth.
What are some alternative theories about the origin of life on Earth?
Several scientists have questioned the latest discoveries and have recommended additional investigation.
Scientists are reigniting a debate about the origin of complex life forms on Earth through a new study.
In the past century, researchers have developed several groundbreaking technologies.
Here, we review some of the most widespread ones.
1. The Original Broth Theory
One of the most widespread theories is the “primordial soup” theory, which proposes that life emerged from organic compounds in a primeval ocean.
(1809-1882) proposed that life initially started in “a warm little pond.”
However, it wasn’t until the 1950s that his theory was actually put to the test. American Nobel laureate Harold Urey, a renowned chemist, and Stanley Miller, a chemist specializing in probiotics, created a simple, primitive atmosphere in a laboratory. They mixed water, methane, ammonia, and hydrogen in a sealed container and introduced electric sparks to simulate the effects of lightning as a catalyst.
After several days, the fundamental constituents of life, known as amino acids, had come into existence.
2. The Cosmic Life Theory
Another interesting idea is that life on Earth actually originated in outer space. According to this theory, life forms or the fundamental components required for life, came from space and established themselves on our planet.
This line of reasoning doesn’t clearly state exactly where life began or what form it took to arrive on our planet. However, the most widely-held idea is that it may have been brought here when a meteorite, carrying microorganisms, collided with Earth.
Two of the theory’s initial supporters were British astrophysicists Fred Hoyle and Chandra Wickramasinghe. Their research in the 1970s revealed that comets contain sufficient organic material to potentially seed life on planets such as Earth.
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The hydrothermal vent hypothesis proposes that life on our planet may have originated at the ocean floor, near hydrothermal vents. These underwater springs issue forth hot, mineral-enriched water through openings in the seafloor.
British geologist Michael Russell, a member of the NASA Astrobiology Institute, hypothesized that underwater alkaline hydrothermal vents, which release hydrogen, hydrogen sulfide, and methane gases, might have furnished the optimal setting for the creation of basic organic compounds.
Although the conditions around hydrothermal vents are considered extreme – they can reach temperatures as high as 400°C (752℉), there are microorganisms that live in these environments using chemosynthesis.
Chemical synthesis is a way certain microbes produce their own sustenance. They utilize energy from chemical reactions, rather than solar power. This enables them to thrive in environments lacking light, including the ocean floor.
4. The RNA world
The RNA world hypothesis suggests that before DNA and proteins existed, the foundation of life on Earth was a flexible molecule called RNA, or ribonucleic acid.
DNA (deoxyribonucleic acid) allows organisms to develop, survive and reproduce and. DNA sequences are converted into messages, or instructions, that enable the production of proteins — complex molecules that are responsible for almost everything that happens in our bodies — and keeps us alive.
RNA undertakes two critical roles in sustaining life: It preserves genetic information and serves as a catalyst for crucial chemical reactions.
In the 1980s, chemists Thomas Cech and Sidney Altman discovered RNA molecules, known as ribozymes, with the ability to act like enzymes, and they received a Nobel Prize for their research.
Scientists have since suggested that RNA molecules which can replicate themselves and facilitate basic chemical reactions predated modern living organisms, and over time, proteins with enhanced catalytic capabilities replaced ribozymes.
The following are some prominent theories regarding the origins of life. They are the most widely circulated within the scientific community.
All, including the latest from Cardiff University, emphasize the intricacy of the question that remains both intriguing and captivating for us today.
Edited by: Zulfikar Abbany
Primary source:
Life on Earth is believed to have become complex approximately 3.3 billion years ago, presents a new study emanating from Cardiff University, dated July 29, 2024.
https://www.cardiff.ac.uk/news/view/2830233-complex-life-on-earth-began-around-1.5-billion-years-earlier-than-previously-thought,-new-study-claims
Author: Fernando Mateos Frühbeck
