Briefly from the Big Bang to the apes.
Venus figurines in context.
Part 1-1
What do the cores of ancient stars, hell of the young Earth, an organism similar to bacteria and apes have in common?
To be consistent, I will briefly start from the most distant point in time, about which we are able to say something definite.
The most distant event since when we have been able to explore the evolution of our universe (or at least the part of Nature that we can perceive as our universe) was a point called the Big Bang. It is dated to about 13.8 billion (13.8 x 109) years before the present. But it was not the actual beginning, but a transformation of one form of existence (of a part) of Nature into another.
Immediately after the Big Bang, our universe was extremely hot and dense. It expanded, cooling down until the extreme hotness disappeared and the time of the dark universe began. This period is known as the Cosmic Dark Ages. But the dark clouds of matter started to form structures similar to a web ("cosmic web") because of gravity and, at the points of the largest density, stars started to glow and the dark era of our universe ended.
In the cores of the stars, elements from which our bodies are composed were formed from the simplest elements, under the conditions of very high temperatures and pressures. These stars first had to explode, dispersing themselves into space, and matter from some of them, after many other transformations, created our Earth and everything that came into existence on it.
So the first answer to the question of how we got here that we come from the stars.
The first era of the existence of the Earth is named the Hadean after the Greek God Hades, the God of the underworld, because the conditions that prevailed on the Earth were likened to the underworld, i.e. to hell. The Hadean dates from the beginning of the formation of the planet Earth (4.6 billion – 4.6 x 109 years before the present) to about 4 billion (4 x 109) years ago.
In the beginning, the Earth was "hellishly" hot, but as it gradually cooled, life became possible.
There are more possibilities how life could have emerged on the Earth in concordance with the natural laws, but we still do not know which of the possibilities is the closest to the truth.
The likelihood of the emergence of life on the Earth may seem incredibly small. Had there been only one planet in the universe, then the existence of life on it would have been almost mystical.
But our universe is unimaginably huge. To give you an idea: there are about 100 billion (1011) stars in our Galaxy (in the Milky Way), and about 2 trillion (2x1012) galaxies in an observable universe, while the observable part of our universe is much smaller than the unobservable one (to say nothing of the possibility of the infinity of the universe). And there are pieces of evidence that our universe may be one of many universes of the multiverse. So even extremely improbable events could have happened somewhere in the universe or multiverse. We can logically ask why it happened on our planet. But if it hadn't happened on the planet Earth, we wouldn't be here and no one would ask such a question.
A number of basic compounds needed for life had already existed in matter from which the planets of the solar system were formed, e.g. a number of amino acids, building blocks of proteins, or all five basic "letters" (nucleic acid bases, nucleobases), of genetic code of every living organism of the planet Earth.
So another answer to the question of how we got here could be that we come from the Hadean aeon, from the hell of the early Earth.
Another answer to the above question of how we got here is that we come from an organism that was the common ancestor of all currently living beings, both animals and plants. It is called LUCA (standing for the Last Universal Common Ancestor). It was a microorganism similar to contemporary bacteria, and already had its genetic information encoded in the nucleic acid DNA, as we have today.
Having an ancestor dated from 4.2 billion (4.2 x 109) years before the present means, that our origin is really very ancient. The existence of LUCA also means that all living creatures on this planet are our more or less distant relatives.
Since the existence of the organism LUCA, life has been evolving, diversifying, new forms of life have been emerging due to mutations. Some were successful and passed on their genes, some were not and became extinct.
Which organisms we can call our ancestors are described in the book "The Ancestor's Tale" by Richard Dawkins.
A lot of time passed, and apes appeared. One of them was the last common ancestor of us humans and chimpanzees, the common chimpanzee (Pan troglofytes) and the bonobo (Pan paniscus).
We have to mention both species, because they diverged from each other after the divergence of the branch that led to humans.
Of all living animals, our human body is most similar to that of the bonobo (Pan paniscus). According to various methods of calculation, the split of the lines of chimpanzees and humans occurred between 6 and 12 million years ago.
I am returning to the beginning of this article. So what do the cores of ancient stars, hell of the young Earth, an organism similar to bacteria and apes have in common?
Without them, we would not be here and now or, more exactly, we wouldn't exist at all.
Following part: 1-2 From apes to humans. Archaic humans, modern humans, Adams and Eves.
Literature
Books
1.
Antonoi del Popolo:
The Invisible Universe. Dark Matter, Dark Energy, and the Origun and End of the Universe.
World Scientific Publishing Co., Pte. Ltd, Singapur, 2021
2.
Andrew Cohen:
The Universe.
HarperCollinsPublishers, Londýn, 2023
ISBN: 978-0-00-838935-2.
3.
Richard Dawkins:
Příběh předka. Pouť k úsvitu života.
Academia Praha, 2008
Articles
1.
Christopher K Jones, Michaela Leung, Chenyi Tu, Saleheh Ebadirad, Nate Marshall, Lin Tan, Tim Lyons:
Setting the stage: Building and maintaining a habitable world and the early conditions that could favor life's beginnings on Earth and beyond.
Submitted on 30 Oct 2024
https://arxiv.org/abs/2410.23344
2.
Edmund R. R. Moody, Sandra Álvarez-Carretero, Tara A. Mahendrarajah, James W. Clark, Holly C. Betts, Nina Dombrowski, Lénárd L. Szánthó, Richard A. Boyle, Stuart Daines, Xi Chen, Nick Lane, Ziheng Yang, Graham A. Shields, Gergely J. Szöllősi, Anja Spang, Davide Pisani,Tom A. Williams, Timothy M. Lenton & Philip C. J. Donoghue:
The nature of the last universal common ancestor and its impact on the early Earth system.
Nature Ecology & Evolution | Volume 8 | September 2024 | 1654–1666 1655
Published online: 12 July 2024
https://www.nature.com/articles/s41559-024-02461-1
3.
Rui Diogo, Julia Molnar, Bernard Wood:
Bonobo anatomy reveals stasis and mosaicism in chimpanzee evolution, and bonobos as most appropriate model for human-chimp ancestor.
Scientific Reports
April 2017 7(1)
DOI:10.1038/s41598-017-00548-3
4.
Tibi Puiu:
If you want a glimpse of an ancient human ancestor, the bonobo might be the closest you'll get.May 2, 2017
https://www.zmescience.com/ecology/animals-ecology/bonobo-shared-ancestor/