Development Of Life On Earth

We all know that atmosphere is continually evolving. We have had ice ages and hotter periods when gators were found in Spitzbergen. Ice ages have happened in a hundred thousand year cycles for the last 700 thousand years. There also have been time periods that seemed to have been hotter than the present in spite of CO2 levels being lower than they are currently. Overall what I am saying is that we have had the medieval warm period and the little ice age. Because of these evolutions there has been different effects on the earth.

It was assumed that these carbon values were unaffected by the diagenesis since aqueous fluids typically have an insignificant amount of carbon in comparison to carbonate rocks. In addition, stratigraphic mapping showed that there was no tectonic activity in this area that would have affected diagenesis either. Results indicated that the proportion of organic carbon to total carbon burial changed from roughly 0.5 before the glacial deposits to virtually 0 immediately after. [Hoffman et al., 1998]. These numbers indicate that life struggled during this interval and the snowball Earth theory might explain why. Oceanic photosynthetic bacteria and eukaryotes would have been severely reduced because global ice cover would have blocked the sun making photosynthesis very difficult. (maybe also use top of 1344 to talk about theory on how snowball earth ended; Should I maybe use separate part of paper for theory and evidence. They tie together pretty

6. The atmosphere of early earth primarily may have consisted of a reducing atmosphere thick with water vapor, along with nitrogen and its oxides, carbon dioxide, methane, ammonia, hydrogen, and hydrogen sulfide.

Describe the important chemistry of early earth and how this may have given rise to life forms.

The evolution of that formation created the world we live in today. The earth has been in existence for a little over four point five billion years to be exact. The earth shares a story that we are still exploring. From its colorful coral reefs in bright and vibrant

Evidence  for  life  on  early  Earth  (e.g.  in  the  Pre Cambrian)  has  proved  difficult  to  find  because: SELECT  ALL  THAT  APPLY Select  one  or  more: A.  rocks  from  these  early  times  are  rare  due to  the  recycling  of  the  Earth's  crust  through plate  tectonics   B.  there  was  no  oxygen  in  the  Earth's atmosphere  at  this  time C.  life  at  this  time  lacked  hard  parts  (such as  shells  or  bones)  that  fossilise  easily   D.  life  had  not  yet  emerged  onto  land E.  life  at  this  time  was  mostly  microbial

5. Why did it take so long for free oxygen to accumulate in the atmosphere and in the oceans?

It has been known for well over a century now that the Earth’s core, mantle and the crust make up the basic structure of the Earth. However, there is some controversy over how and when the Earth produced its core, mantle and crust. In this essay, I will first discuss about the formation of the Early Earth and its Moon, then about the methods used to pinpoint the age of the Earth. Other than that, I will also expand on core and mantle formation, as well as the eventual production of the continental crust.

The oxygen revolution: During the Proterozoic, biotic system were being established, which gave rise to biomass of the prokaryotic organisms like the “benthic and planktonic photosynthesizing organisms” Due to the vast developing diversity of environment, organisms could well adapt to these various environments, which increased the input of oxygen on Earth. Hence, in order for the oxygen to be accumulated in the atmosphere, Iron and Sulfur like oxygen-sinks had to be depleted.

In the beginning, impacts of very large objects were very common, some as big as Mars or half the diameter of Earth. Collision of large bodies orbiting Earth played a role in its initial tilt of spin axis, the length of its day, direction of spin, and the thermal state of the interior. This violent bombardment continued for 3.9 billion years. Final composition of Earth had several crucial structural effects. Enough metal was present early on to allow formation of an iron and nickel rich core that is partially liquid. This enables a magnetic field that deflects some harmful radiation from reaching the surface. Enough radioactive elements are also present in the core to maintain long term heating which drives plate tectonics. At 4.5 billion years ago, Earth separated into different layers: an inner core (made of iron and nickel), a land layer of lower density material, and an early atmosphere of carbon dioxide and steam. At 3.9 billion years ago, surface temperatures dropped to a range where liquid water could be maintained. Liquid water makes up approximately 75% of the planet's surface today which is roughly what it was then. The most important requirement for life as we know it is the presence of liquid water. This is the one substance that can serve as a universal solvent - that is, it can dissolve and transport minerals and

This essay is a compilation of numerous hypothesis’ of how life on Earth began. The six hypotheses’ are: Primordial Soup, Iron Sulfur, Deep Sea Vent, RNA World, Community Clay, Panspermia. Primordial Soup was suggested by two scientist Alexander Oparin and J.B.S. Iron Sulfur was proposed by Gunter Wachtershauser. Deep Sea Vent was proposed by scientists Nick Lane and Bill Martin. RNA World was brought forth by scientists Sidney Altman and Thomas Cech.

Life has continually perplexed and fascinated individuals since the dawn of mankind. The subject’s complexity is so great even over the course of human existence only a minute fraction of its mysteries have been unraveled. A phenomenon which has always intrigued scientists is the origin of life on Earth, and in recent years significant advancements have been made in the understanding of this enigma. This essay will briefly outline two theories regarding life’s origin on Earth to further comprehend why an explanation for this phenomenon has been so difficult to reach.

According to astronomical research and geological evidence, scientist indicate the universe is approximately thirteen thousand eight hundred and twenty billion years old. The first link to humanity started with a primate group called Ardipithecus. While our ancestors have been around for about six million years, the modern form of humans only evolved about two hundred thousand years ago. The age of the Earth is estimated about four point fifty four billion years because that is the age of the oldest rocks with fossil evidence of life on earth. The oldest rocks on Earth found to date are the Acasta Gneisses in northwestern Canada near the Great Slave Lake, which are four point three billion years old. The study of the origin of life on Earth, more specifically abiogenesis, is the natural process of life arising from non-living matter. Life on Earth is believed to have began from organic compounds about three point eight to four billion years ago. Despite several competing theories for how life arose on Earth scientist only know when life first appeared on Earth and are still far from answering how it appeared. Since it is hard to prove or disprove them, no fully accepted theories of the origin of life exists.

Soon after the birth of earth, it was a very different place from the one we know today.

One of the main theories is that life started by chemical means in a rock where water, methane, ammonia and hydrogen were all present then with the added effect of lightening simple organic molecules formed the building blocks of life. There was an experiment that was conducted in 1953 by Miller and Urey that supports that the conditions above could stimulate organic compounds to form. *copied “ The Miller-Urey experiment attempts to recreate the chemical conditions of the primitive Earth in the laboratory, and synthesized some of the building blocks of life.