first photox bacteria evolved 3.6 bya billion years ago

This implies that life originated some time before this. Currently the oldest fossil evidence found (3.6 billion years old) confirms that life was in existence approximately 950 million years after the formation of the Earth. Researching the time at which the first unicellular life evolved is very complex. The oldest known rocks on Earth are around 3.8 billion years old. One difficulty with obtaining very old fossils is that the encasing rocks must have undergone negligible erosion or remelting since the original deposition of the rocks. Sedimentary rocks often contain fossils that record details of the existence of organisms that lived long ago. For more about these ideas see the focus idea The very slow movement of tectonic plates is a central idea in geology that explains many phenomena such as mountain building, earthquakes and the folding and faulting we see in rock strata. The movement of these plates is so slow that these speeds can only be determined by periodic satellite measurements. the Indian tectonic plate is pushing north under the Eurasian plate at a rate of about 5cm per year, resulting in the creation of the Himalayan mountain range. The processes which cause these changes (the movement of tectonic plates) continue to operate today. Mountain ranges have been formed only to be eroded away to reform new mountain ranges many times. Since the Earth’s formation, continents have been continuously moving across its surface, changing their positions compared to each other. Recent astronomical data confirms that this event was many billions of years after the formation of the universe during the Big Bang. Research: Blake (2005), Dove (1998),Trend (2001), Marques & Thompson (1997), Kusnick (2002), Phillips (1991) Scientific viewĬurrent evidence, based on terrestrial and astrophysical data and radioactive isotope dating, suggests the solar system formed (along with our Earth) around 4,540 million years ago. soil is formed rapidly (from rotting organic matter such as dead leaves and plants).soil has always been there, and all soil was formed when the Earth formed.mountains are formed very quickly from processes like earthquakes and volcanoes.No mountains are forming or being removed by erosion at present landforms such as mountains, rivers, seas have always existed in their present form.

the Earth hasn’t changed – how it is now is how it has always been, e.g.

the appearance of life and the formation of the Earth occurred at the same time.Other views held by students include perceptions that: Students often overlook the fact that land animals have been present for only a small fraction of the Earth’s geological age and humans for an even smaller fraction. Students often fail to appreciate that although most geological events occur very slowly, the immense time scales involved allow vast and dramatic physical changes to the Earth’s surface to eventuate.įurther confusion can be created by the less widely held student view that humans have existed for most of geological time or the religious belief held by a few that the age of the Earth is very, very much less than that predicted by current scientific evidence. They frequently describe very short time periods for geological processes like rock and mountain formation, and perceive the erosion that results in the creation of canyons and valleys as occurring within human time scales. Students often confuse or attempt to compare the notions of human historical time periods (in the order of centuries or millennia) with vast geological time scales. Time spans as immense as millions, hundreds of millions or billions of years, carry little meaning for students, and hence students form understandings of the Earth’s history very different from those of scientists. The difficult notion of the enormous expanse of geological time is far beyond what most students and many adults can conceptualise. Contrasting student and scientific viewsĬontrasting student and scientific views Student everyday experiences.

First photox bacteria evolved 3.6 bya billion years ago