From the 'X-Files' Dept: "Life May have had Multiple Origins in the Universe"
Life originated in a nebular cloud, over 10 billion years ago, but may have had multiple origins in multiple locations, including in galaxies older than the Milky Way according to Rudolf Schild of Harvard-Smithsonian Center for Astrophysics and Rhawn Joseph of the Brain Research Laboratory.
Multiple origins, they believe, could account for the different domains of life: archae, bacteria, eukaryotes. The first steps toward life may have been achieved when self-replicating nano-particles initially comprised of a mixture of carbon, calcium, oxygen, hydrogen, phosphorus, sugars, and other elements and gasses were combined and radiated, forming a nucleus around which a lipid-like permeable membrane was established, and within which DNA-bases were laddered together with phosphates and sugars, a process which may have taken billions of years.
DNA-based life, they propose, may be a "cosmic imperative" such that life can only achieve life upon acquiring a DNA genome. Alternatively, the "Universal Genetic Code" may have won out over inferior codes through natural selection. When the first microbe evolved, it immediately began multiplying and spreading throughout the cosmos via panspermia carried by solar winds, Bolide impact, comets, ejection of living planets prior to supernova which are then captured by a newly forming solar system, galactic collisions and following the exchange of stars between galaxies. Bacteria, archae, and viruses act as intergalactic genetic messengers, acquiring genes from and transferring genes to life forms dwelling on other planets.
Viruses also serve as gene depositories, storing vast numbers of genes which may be transferred to archae and bacteria depending on cellular needs. The acquisition of these genes from the denizens of other worlds, enables prokaryotes and viruses to immediately adapt to the most extreme environments, including those that might be encountered on other planets.
Whether the universe was created by a Big Bang Universe or an Eternal Infinite Universe, once life was established it began to evolve. Archae, bacteria, and viruses may have combined and mixed genes, fashioning the first multi-cellular eukaryote which continued to evolve.
Initially, evolution on Earth-like planets was random and dictated by natural selection. Over time, increasingly complex and intelligent species evolved through natural selection whereas inferior competitors became extinct. However, their genes were copied by archae, bacteria, and viruses.
If the first steps toward life in this galaxy began 13.6 billion years ago, then using Earth as an example, intelligent life might have evolved within this galaxy by 9 billion years ago. As life continued to spread throughout the cosmos, and as microbes and viruses were cast from world to world, genes continued to be exchanged via horizontal gene transfer and copies of genes coding for advanced and complex characteristics were acquired from and transferred to eukaryotes and highly evolved intelligent life.
Eventually descendants of these microbes, viruses, and their vast genetic libraries, fell to the new born Earth. The innumerable genes stored and maintained in the genomes of these viruses, coupled with prokaryote genes and those transferred to eurkaryotes, made it possible to biologically modify and terraform new Earth, and in so doing, some of these genes, now within the eurkaryote genome, were activated and expressed, replicating various species which had evolved on other worlds.
Genes act on genes, and genes act on the environment and the altered environment activates and inhibits gene expression, thereby directly influencing the evolution of species.
On Earth, Schild and Joseph conclude, "the progression from simple cell to sentient intelligent being is due to the activation of viral, archae, and bacteria genes acquired from extra-terrestrial life and inserted into the Earthly eukaryote genome. What has been described as a random evolution is in fact the metamorphosis and replication of living creatures which long ago lived on other planets."
The new image below was taken this summer by the newly installed Wide Field Camera 3 on the refurbished Hubble Space Telescope. Faint red smudges identified on the above image likely surpass redshift 8 in distance. These galaxies therefore likely existed when the universe was only a few percent of its present age, and may well be members of the first class of galaxies. Some large modern galaxies make a colorful foreground to the distant galaxies. Analyses by the HUDF09 team indicate that at least some of these early galaxies had very little interstellar dust. This early class of low luminosity galaxies likely contained energetic stars emitting light that transformed much of the remaining normal matter in the universe from a cold gas to a hot ionized plasma.
Provided by The Daily Galaxy
