Difference Between Spontaneous Generation and Biogenesis

The main difference between spontaneous generation and biogenesis is that the spontaneous generation is a hypothesis that describes the origin of life from non-living things whereas the biogenesis is a hypothesis that describes the origination of life from pre-existing forms of life. Furthermore, spontaneous generation or abiogenesis has not been proved by scientific experiments while biogenesis has been proven by scientific experiments.

Spontaneous generation and biogenesis are two hypotheses that describe the origin of life. Due to the scientific background of biogenesis, it is the most widely accepted phenomenon for the origination of life.

Key Areas Covered

1. What is Spontaneous Generation
     – Definition, Hypotheses, Evidence
2. What is Biogenesis
     – Definition, Scientific Experiments
3. What are the Similarities Between Spontaneous Generation and Biogenesis
     – Outline of Common Features
4. What is the Difference Between Spontaneous Generation and Biogenesis
     – Comparison of Key Differences

Key Terms

Aristotelian Abiogenesis, Biogenesis, Origin of Life, Pasteur’s Experiment, Spallanzani’s Experiment, Spontaneous Generation

What is Spontaneous Generation

Spontaneous generation is one of the theories built to describe the origin of life. It states that life originated from inorganic or inanimate materials. Spontaneous generation is also called Aristotelian abiogenesis due to its ancient Greek proponent. The belief of spontaneous generation first evolved due to the invisibility and stealth of some organisms such as mice, flies, and bacteria. In 1668, Francesco Redi hypothesized macroscopic spontaneous generation with the observation of the growth of maggots in rotting meat. But, with the invention of the microscope in the 18^th century, this credibility was eroded since people could see fly eggs as well as bacteria through microscopes.

Figure 1: Putative Fossilized Microorganisms found in Hydrothermal Vent, The Earliest Known Life-Forms on Earth

It is considered that the earth was formed 4.54 million years ago. The earliest, undisputed evidence of life on earth are microbial mat fossils discovered from a 3.48 million years old sandstone in Western Australia. Some studies state that the origination of life on earth started even before 4.25 million years.

Figure 2: Stromatolites, Pre-Cambrian Petrified Biofilm in Lacier National Park, Montana

With the assumption that the life spontaneously originated on earth, Miller–Urey experiment and similar experiments attempted to demonstrate the formation of basic chemicals of life such as amino acids in similar conditions to the early earth. Lightning and radiation provided energy for these chemical reactions. Another hypothesis, the ‘metabolism first’ hypothesis, focuses on the catalysis of chemical reactions, which are considered to provide the precursor molecules required by self-replication.

What is Biogenesis

Biogenesis is another hypothesis that describes the origin of life on earth, stating that life forms produce new life forms. Lazzaro Spallanzani was the first person to disprove spontaneous generation. In 1767, he proved that microorganisms can be killed by boiling. He boiled meat in a sealed container and this broth did not show bacterial growth subsequently. In 1864, Louis Pasteur disproved the spontaneous generation with a series of experiments similar to that of Spallanzani. He demonstrated that life does not arise in areas that have not been contaminated by existing life. Pasteur’s experiment is described below.

Figure 3: Pasteur’s Experiment

Biogenesis is the widely accepted hypothesis for the origin of life since it can always be proved by scientific experiments.

Similarities Between Spontaneous Generation and Biogenesis

• Abiogenesis and biogenesis are two hypotheses that try to describe the origin of life on earth.

Difference Between Spontaneous Generation and Biogenesis

Definition

Abiogenesis refers to the supposed production of living organisms from non-living matter, as inferred from the apparent appearance of life in some supposedly sterile environments. Biogenesis refers to the hypothesis that living matter arises only from other living matter. This indicates the difference between spontaneous generation and abiogenesis.

Proposed by

Some of the proponents of spontaneous generation were Francesco Redi, Alexander Oparin, Stanley Miller, and Harold Urey while some of the proponents of biogenesis were William Harvey, Theodore Schwann, Lazzaro Spallanzani, John Needham, and Louis Pasteur.

Significance

Spontaneous generation states that life on earth has originated from non-living compounds while biogenesis states that life on earth originated from the pre-existing living forms.

Scientific Evidence

Spontaneous generation has not been scientifically proved while biogenesis has been proved by scientific experiments.

Based on

Spontaneous generation is based on observations and rational thoughts while biogenesis is based on practical experiments and material evidence. This another important difference between spontaneous generation and abiogenesis.

Conclusion

Spontaneous generation states that life on earth originated from non-living things while biogenesis states that life on earth originated from pre-existing living things. This is the main difference between spontaneous generation and abiogenesis.

Reference:

1. “Theory of Abiogenesis.” The Center for Planetary Science, Available Here
2. Dohrman, Paul. “The Theory of Biogenesis.” Sciencing, 25 Apr. 2018, Available Here

Image Courtesy:

1. “Champagne vent white smokers” By NOAA – (Public Domain) via Commons Wikimedia 
2. “Stromatolites” By P. Carrara, NPS – National Park Service – http://www.nature.nps.gov/geology/cfprojects/photodb/Photo_Detail.cfm?PhotoID=204 (Public Domain) via Commons Wikimedia
3. “Pasteur’s experiment testing spontaneous generation and biogenesis” By Thebiologyprimer – Own work (CC BY-SA 4.0) via Commons Wikimedia