The mystery of life's origin deepens

Sabine Hossenfelder told about new study, which deepens the mystery of life’s origin (see this). The key notion is LUCA, life’s universal common ancestor, whose genome should be common to all life forms, which in the most general case involves both archaea, prokaryotes (bacteria), and eucaryotes (plants, fungi and animals).

The newest study gives a considerably larger number than the previous estimates.

1. LUCA would have 2,657 genes. Luca would have had 2.7 million bps to be compared with about 3 billion bps of humans. LUCA would have lived about 4.2 billion years ago.
2. The proteins coded by the genes of LUCA suggest that hydrogen was important in the metabolism of LUCA. Presumably LUCA lived near volcanoes. LUCA also had a rather complex metabolic circuitry and the genome suggests that it was a part of an ecosystem. The size of LUCA is 10 &mu:m in size, which is also the size of cell nucleus, and it has a genome but no nucleus.
3. An interesting side observation is that 2,657 is prime and forms a twin prime together with 2659. Maybe number theory is deeply involved with the genome.
4. The earlier estimate for the gene number of LUCA by Bill Martin’s team (see this) left only 355 genes from the original 11,000 candidates, and they argue that these 355 definitely belonged to LUCA and can tell us something about how LUCA lived.

The problem is that there are two widely different candidates for the LUCA and the new candidate seems to be too complex if one assumes a single evolutionary tree.

The mystery of Cambrian Explosion

Cambrian Explosion represents a long standing mystery of evolutionary biology (see the book “Wonderful Life” of Stephen Gould). The basic mystery is that highly evolved multicellular life forms emerged suddenly in the Cambrian explosion about .5 billion years ago. There are much older fossils of monocellular life forms archaea and prokaryotes and they would have lived at the surface of Earth as separate evolutionary lineages.

The TGD based solution of the mystery mystery of Cambrian Explosion does not involve ETs bringing multicellular life to the Earth (see this). .

1. In the TGD Universe, quantum gravitation is possible in arbitrarily long scales and cosmic expansion is replaced by a sequence of quantum phase transitions occurring in astrophysical scales as very rapid local expansions between which there is no expansion.
2. The life on Earth could have evolved in two ways and as three separate evolutionary trees. Multicellular life forms possible for sexually reproducing eukaryotes would have evolved in the underground oceans, where they were shielded from meteor bombardments and cosmic rays. There are indications that underground oceans and underground life are present on Mars and possibly also some other places in the solar system.
3. In the Cambrian Explosion, identified as a short lasting rapid local cosmic expansion, the radius of Earth would have increased by a factor of two. This hypothesis was originally inspired by the observation of Adams (see this) that the continents seem to fit nicely together if the radius of Earth is taken to be 1/2 of its recent radius. This hypothesis would generalize the continental drift theory of Wegener. Rather highly developed photosynthesizing multicellular life forms would have bursted to the surface of Earth from underground oceans and oceans were formed (see this, this, this, and this).

The TGD proposal for the solution of the LUCA mystery relies on the solution of the mystery of the Cambrian explosion. Bacteria and archaea would have evolved at the surface of the Earth and eukaryotes having a cell nucleus and reproducing sexually in the underground oceans. Bacteria and archaea would have evolved from a counterpart of LUCA having a much smaller genome and eukaryotes would have evolved from an archaea with maximum size, which became the nucleus of the first eukaryote, LUCA.

See the article Some mysteries of the biological evolution from the TGD point of view and the chapter Quartz crystals as a life form and ordinary computers as an interface between quartz life and ordinary life?.

For a summary of earlier postings see Latest progress in TGD.

For the lists of articles (most of them published in journals founded by Huping Hu) and books about TGD see this.