A University Press Release Is Mostly Honest, But Ends With "Seeds of Life" BS

Scientists have long appealed to the idea that chemical precursors of life were delivered to Earth eons ago by comets.  For example, the scientific paper here states, "Thus, comets may have imported prebiotic elements to early Earth, which, when mixed with liquid water, may have allowed the synthesis of all molecules thought to be necessary for the origin of life." This idea always seemed nutty, because a colliding comet would be vastly more destructive than an exploding atomic bomb, as the Google Gemini infographic below explains (mentioning that a colliding comet would have a force of trillions of megatons). 

The "delicate precursors of life from colliding comets" idea is  discredited by a recent press release from the University of Cambridge. We had this headline:

Comets probably didn’t seed life on Earth after all, new study suggests

We read this:

"The theory that comets delivered the molecular building blocks for life on Earth is a long-standing one, since comets are known to carry many of these molecules. However, a new study challenges this idea. 

The researchers, led by the University of Cambridge, found the cometary delivery of these building blocks would be – at best – a ‘one-off fluke’, and not the steady rain of prebiotic molecules that had been theorised.

Using computer modelling, the researchers determined that comets travel too fast and at too sharp an angle to Earth’s atmosphere for the fragile organic molecules to survive: they would almost certainly vaporise on impact with the surface. However, the researchers also found that another planet in our system – Mars – could be a slightly more promising candidate for cometary delivery of prebiotic molecules, although this is still highly unlikely. The results are published in the journal Scientific Reports."

Referring to hydrogen cyanide, the scientific paper tells us that "HCN is the only feedstock molecule observed in Solar System comets in prebiotically relevant concentrations." That seems to discredit ideas that things such as amino acids (molecules needed for the origin of life, and much more complex than hydrogen cyanide) might have arrived from comets.  Referring to the delivery of life or its precursors to Earth from comets, the paper refers to "the crux of long-standing objections to cometary delivery, which relate to both the destruction of comets during atmospheric passage, and the thermal destruction of fragile organic species during hypervelocity impact."  The paper states, "Despite representing a best-case scenario for cometary delivery, our Monte Carlo simulations of Earth’s early cometary bombardment record, on average, zero cometary impacts delivering a prebiotically relevant concentration of HCN (> 10 mM)."

The paper authors state this:

"We have shown via Monte Carlo simulation of Earth’s cometary bombardment that these comets were, on the whole, unable to deliver these fragile organic molecules to Earth’s surface intact. Our results demonstrate that, on both global and local scales, cometary impacts provided an insignificant source of the concentrated feedstock molecules required for prebiotic chemistry, challenging the long-held hypothesis that comets played an important role in the origins of life on Earth."

No one should be surprised by this conclusion. The idea that something biological (or even complex chemistry) could come from a comet and survive the comet crashing into Earth (and without being incinerated as the comet came through the atmosphere) was always hugely unbelievable. There's a reason why meteors light up the sky so dramatically as fireballs entering the atmosphere. It's because some rock has become super-heated.  

The University of Cambridge press release announcing these findings does not manage to inform us intelligently throughout its text. Instead, at its end it shifts into BS-shoveling mode (a mode that very many university press releases shift into at their very beginning).  Near its end, the press release states this:

"So where did the molecular seeds of life on Earth come from? The researchers say there are several possibilities, including the synthesis of these molecules following the impact of asteroids, which hit the Earth far more frequently than comets. Or, the chemical precursors formed from processes that occurred on Earth itself, without any outside interference." 

Alas, we have the utterly unscientific has-no-basis-in-fact idea that there is any such thing as "seeds of life." What is a seed? It is something that will grow into a living plant, as long as you supply sunlight, water and soil. Do we know of any such thing corresponding to the appearance of life from non-life? No, we do not.  There are no chemicals that cause life to appear from a sterile environment without life. There are no such things as "seeds of life." The use of that term is a bad deceptions of scientists and science journalists talking about the origin of life. 

Claiming that there are chemicals that are "seeds of life" causing life to arise from non-life is as deceptive as claiming that are types of nuts or bolts that are seeds of automobiles. The number of well-arranged parts in even the simplest self-reproducing cell is comparable to the number of well-arranged parts in an automobile. A car has about 30,000 well-arranged parts. Even the simplest self-reproducing cell requires hundreds of types of proteins, each of which has an average of hundreds of very well-arranged amino acids. Multiply 200 by 200 and you get 40,000.

As for the idea that you could have got the complex components needed for life from asteroids bombarding Earth, all we should say about that is: crazy as colliding comets. 

I'll end by citing the first quote in my "Candid Confessions of the Scientists" post:

"The transformation of an ensemble of appropriately chosen biological monomers (e.g. amino acids, nucleotides) into a primitive living cell capable of further evolution appears to require overcoming an information hurdle of superastronomical proportions (Appendix A), an event that could not have happened within the time frame of the Earth except, we believe, as a miracle (Hoyle and Wickramasinghe, 1981, 1982, 2000). All laboratory experiments attempting to simulate such an event have so far led to dismal failure (Deamer, 2011; Walker and Wickramasinghe, 2015)." -- "Cause of Cambrian Explosion - Terrestrial or Cosmic?," a paper by 21 scientists,  2018.