The anthropic principle says that we, observers, exist. We exist in this Universe, and therefore the Universe exists in a way that allows observers to come into existence.
It is the initial condition of the universe that needs to be fine-tuned, not the value today. The laws that govern the universe need to be calibrated
before they startup. Life can only evolve because these laws and conditions must be in tune to function correctly from the get-go. One component that is off-track would make life impossible. The universe is the original machine, and it needed to be set up correctly at the start-up.
All life forms are carbon-based. Carbon is formed by nuclear reactions in stellar interiors that combine three helium nuclei to make a carbon nucleus.
Most of the carbon for life forms on earth came from a collision about 4.4 billion years ago between Earth and an embryonic planet similar to Mercury. OR NOT: A recent study states: When presolar stars died, they expelled gases; most carbon on Earth probably came from the interstellar medium, or material drifting between the stars in our galaxy, arriving around the time the solar system was still in its embryonic phase. Carbon-rich stardust formed within the outflowing and cooling gases. These grains would float around in interstellar space, and some got incorporated into the Solar Nebula.”
The unique bonding ability of carbon enables it to form many different forms, such as charcoal, graphene, and diamond. In bonding with other elements, carbon can create a diverse category of organic compounds. Most life forms do not use all the elements in the periodic table. Carbon is a primary component of all known life on Earth, representing approximately 45–50% of all dry biomass. Complex biological molecules consist of carbon atoms bonded with other elements, especially oxygen and hydrogen, and frequently also nitrogen, phosphorus, and sulfur (collectively known as CHNOPS).
Carbon can form many compounds, more than any other element, with almost ten million compounds described to date. Carbon is the 15th most abundant element in the Earth’s crust, and the fourth most abundant element in the universe by mass, after hydrogen, helium, and oxygen. The most important characteristics of carbon as a basis for the chemistry of life are that each carbon atom is capable of forming up to four valence bonds with other atoms simultaneously and that the energy required to make or break a bond with a carbon atom is at an appropriate level for building large and complex molecules which may be both stable and reactive.
The most special classes of biological macromolecules used in the fundamental processes of living organisms include:
Proteins are the building blocks from which living organisms’ structures are constructed (this includes almost all enzymes, which catalyze organic chemical reactions).
