Dr Irengbam Mohendra Singh
The level of support for the spontaneous origin of life 3.5 billion year ago, perhaps in a “warm little pond” as speculated by Darwin, is now accepted by an overwhelming majority. However, there is still a handful who believes that life was created by ‘Intelligent design’ (ID), with hair-raising absurdism and a venomously funny streak.
Recently, the distinguished German palaeontologist, who specialises in fossil dragonflies preserved in amber for millions of years, has been erased by Wikipedia editors for his support of ID, ostensibly for not being “notable” enough. He has also been pushed out as a curator of the State Museum of Natural History in Stuttgart, Germany.
As I’m also a believer in Darwinian evolution we’ll take a little literary latitude in this article to make a point to the scientific concept of the beginning of life from inorganic matter. The origin of life can be explained better by physics today rather than by biology. Life, including that of the smallest organisms – bacteria, is an incredibly complex biological process that exploits external environment such as oxygen, which was unavailable to the first organisms. The simplest bacteria known as Carsonella ruddi with 182 different proteins, are only two ten-thousandths of a millimetre across. They are made of billions of individual interacting atoms. Each bacterium has a billion times the volume of a carbon atom.
The idea that life could just pop out from inorganic or dead matter, known as ‘spontaneous generation’ is rather ridiculous. So, many people satisfy themselves with an equally preposterous idea that an entity called God created life for the first time. Since we don’t know what God is, the idea is scientifically unsustainable, whilst science has some proof that life could have begun from nonliving matter.
The Earth came into existence 4.5 billion years ago after the Big Bang that occurred 15 billion years ago. Life on Earth emerged 3.5 billion years ago, as evidenced by the discovery of the oldest fossils of iron-oxidising bacteria found in Northern Quebec, Canada.
The current scientific theory is that life originated from inorganic chemicals with the energy of the Sun from the warm “primordial soup”(cf. author’s books: Quest Beyond Religion, 2006, pp273-286 and Points to Ponder, 2013, pp273-276). The theory is not new, and yet some physicists do not support it as it doesn’t conform with the second law of thermodynamics (vide infra).
Spontaneous generation of certain forms of life from inorganic matter had been firmly believed by Aristotle (4th century), such as flies from putrid matter, maggots from dead flesh, or crocodiles from rotting logs. The idea continued to be supported by Western scholarship until the 19th century.
In late 19th century, the theory of spontaneous generation was put to an end by Louis Pasteur, a French microbiologist, who experimentally proved in 1859, that there is no such thing as spontaneous generation. He expanded upon Francesco Redi, an Italian physician and naturalist, who in 1668, for the first time, demonstrated by experiment, that no maggots appeared in meat when flies were prevented from laying eggs.
The primordial soup theory explains that following ‘chemical revolution’ ie the chemical process that took place on the early Earth, came the initiation of ‘biological evolution’ ie replication, variation, and natural selection. This was demonstrated by Sol Spiegelman, American molecular biologist, who in 1961, studied bacterial virus that brought a wave of “life in a test tube”, and by Manfred Eigen, German Nobel Prize winner in chemistry, in 1967, which led to the “first cells” or protocells (organisms using light for energy) that existed on Earth.
But so far, no protocell has been synthesised using basic components known as the basic blocks of life. The nearest plausible experiment was the successful creation of life for the first time in 2010 by Craig Venter, an American biochemist/geneticist and others at J Craig Venter Institute in Rockville. Maryland, US. They engineered prokaryotic cells (earliest bacteria without nuclei) with progressive fewer genes, to discern at which point the most minimal requirements for life as the forerunner of life on Earth was reached.
Charles Darwin 150 years ago, contrasted with the metaphysical theory of “creation” of each species independently by God. In 1871, he suggested that the original spark of life may have begun in a “warm little pond”. In his book, On The Origin Of Species, Darwin wrote of life having been “created” and regretted later, for using the Old Testament word “creation”, as he really meant “appeared” by some wholly unknown process.
Fifty years later, Darwin was supported by Alexander Oparin, the Russian biochemist, who wrote ‘The Origin of Life’ in 1922 (translated into English in 1967), and by another British-born biologist JBS Haldane, who also independently wrote in 1925 with the same title, ‘The Origin of Life’. Oparin wrote: “Life is not characterised by any special properties but by a definite, specific combinations of a large number of properties which are present in isolation in various dead matter.” Haldane wrote: “The link between living and dead matter is therefore somewhere between a cell and an atom.” The idea that life could have its origin beyond Earth was raised by both authors.
Human bodies need oxygen from air to produce heat. This, we do by burning food with oxygen which is replenished from photosynthesis by plants and algae. A researched theory has demonstrated that atmospheric oxygen was absent in the beginning of the Earth, and that helped the formation of basic molecules – proteins, carbohydrates, lipids and nucleic acids with electrical energy.
The current theories of the origin of life are still based on the framework laid out by Oparin and Haldane. They postulated the molecular or chemical evolution theory of life . That means the earliest cells were synthesised, consisting of molecules under natural conditions by a slow process of molecular evolution. These molecules then organised into the first simple ‘molecular system’ having properties with ‘biological order’ (ie taxonomic rank used in classifying organisms) from the Earth’s prebiotic oceans (different from their modern counterparts), and would have formed a “hot dilute soup” in which organic compounds could have formed. [Organic compounds contain one or more carbon atoms].
This idea of ‘prebiotic soup’ or Darwin’s ‘warm little pond’ as the origin of life, was famously demonstrated in 1953 by the Nobel Prize-winning chemist Harold Urey and his PhD student Stanley Miller at the University of Chicago. They showed how organic molecules could have spontaneously formed from inorganic substances that were thought to have existed in the atmosphere of the young Earth.
They constructed a model primordial ocean inside a 5-litre sterilised flask, filled with methane, ammonia and hydrogen, simulating the contents of the prebiotic atmosphere. High voltage electrical sparks were delivered by two electrodes, mimicking lightning. The experiment continued for over a week, when they tested for signs of organic life. They found aminoacids (proteins), the building blocks of life. No further breakthrough.
The hypothesis that basic elements of life on Earth could have come from space has recently been confirmed by astronauts in October 2016. They reported their finding that the very basic chemical ingredients of life, carbon-hydrogen molecule, is formed in a large part, as a result of ultraviolet light from stars. They postulated two possible sources of organic molecules on the early Earth: (1) terrestrial origins, and (2) extraterrestrial origin.
In the modern view, the primordial soup theory has encountered some problems with physicists who say it goes against the second law of thermodynamics ie “The entropy [gradual decline] of an isolated [closed] system [eg universe] always increases”. It means unconstrained energy will spontaneously tend to spread out over time. For example, “heat” will flow from hotter [more concentrated energy] to cooler [less concentrated energy] and never the other way round. Since entropy is just a measure of this energy dispersion, entropy must always increase.
Entropy is gradual decline into disorder or the unavailability of a system’s thermal energy for conversion into mechanical work. Living things including bacteria are highly ordered and therefore have a very low entropy. Things become more disordered as time passes eg dead birds decay. No matter how long you wait, no single cell will emerge by chance in an isolated stewing pond or the ‘primordial soup’.
Physicist professor Brian Cox views that Life on Earth probably didn’t begin in a warm primordial soup (believed for 90 years), because the thermodynamic gradients [temperature, pressure and concentration] were too gentle to drive the emergence of complexity. Rather, the origin of life was something that lived in those ancient undersea vents four billion years ago where naturally occurring proton gradients provided the energy for the first life. It’s a scientific fact that all known life today uses proton gradients to produce energy in the cells’ mitochondria that keeps life thriving.
However, Austrian Novel Prize winner quantum physicist, Erwin Schrodinger 70 years ago, argued that living things apparently defy the 2nd law of thermodynamics: “the events within the boundary of an organism cannot be understood in isolation, because organisms are not isolated systems. They can be understood only when viewed as intimately and essentially coupled to their environment.”
The writer is based in the UK. Email: [email protected] Website: www.drimsingh.co.uk.
I might add that human body is now composed of very complex molecules of water, protein fat, carbohydrate, connective tissue and hydroxyl apatite (in bone) and DNA.