Life and Natural Selection Essay example

Submitted By Genesis-Bernat
Words: 1109
Pages: 5

Genesis Bernat

University of Phoenix

SCI 151

Astronomy Research and the Search for Extraterrestrial Life

Prof. Jorge Espinosa

Everyday life is born into our home planet, Earth. Just the same as life comes to be, it can take its last breathe in the same day. Life is brilliant and fragile. On Earth we can find living organisms as small as microscopic bacteria, medium sized, like us humans, and as big as an elephant. We humans boast to be the smartest living creatures on this rock. We share many instincts as many other animals with lesser brain capacities do. Our instincts push us to survival and curiosity. Human intelligence has unlocked many answers about life and our planet. We discover new species constantly. We are definitely not alone here on earth. Scientists have done well to answer how and where we began. The theories of the genesis of life and theory of natural selection give great scientific explanation to how life on this planet functions. Life is defined as “the condition that distinguishes organisms from inorganic objects and dead organisms, being manifested by growth through metabolism, reproduction, and the power of adaptation to environment through changes originating internally (2015).” Human life on Earth depends desperately on oxygen and water. Without these resources human life and many other forms of life would cease to exist. Life on Earth ranges in many forms. We have small insects, mammals, and reptiles. Plants also go through life cycles. Every animal has different habitats, functions, defenses, and attack methods. Three billions years ago life began to evolve in a primordial soup. Life started as basic single celled microbes and evolved into an astounding array of complex multi-cellular entities. There is no definitive answer to our beginning. Many theories try to explain our origins. A theory of a violent world with constant electrical sparks generated through our atmosphere generated amino acids and sugars, the essential building blocks of life, through interaction with atmosphere rich in water, methane, ammonia and hydrogen as present on this primitive planet. A deep-sea vent theory suggest that life began to be around deep submarine hydrothermal vents. These hydrothermal vents give off hydrogen-rich molecules. The geography of the ocean floor could have trapped these molecules allowing build up. The vents also giving off rich thermal and chemical energy allowing reactions that could give birth to life and a sustainable ecosystem. The most interesting and “outside of this world” theory is that of Panspermia. The theory of Panspermia details the possibility that life did not begin on Earth at all. Life frozen or present on rogue rocks that were blasted off of Mars by violent impacts became vessels of Martian life that were transported by chance and struck Earth. The same theory encompasses the possibility of the same situation but coming from comets and asteroids from different star systems. “However, even if this concept were true, the question of how life began on Earth would then only change to how life began elsewhere in space (2011).” Given that life originated from a great primordial soup as minute molecules. It brings up the question of how our current life form exits. Enter the theory of natural selection. We can give thanks to Charles Darwin for this brilliant theory that best gives answer to our existence. Natural selection’s main point is that of all the species that every existed on the strongest survive. Character traits of animals that are best suited for survival will continue to be passed on and those that do not, will phase away. Darwin also contemplated that a species that eventually changed enough traits through selection could also possibly become a different creature. “There are plenty of proven cases of adaptation, which involves non-genetic changes. There are examples of natural selection changing the balance of populations within a species.