Explain The Four Different Eras

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There are four different periods of the world known as eras. The four different eras are the Cenozoic, Mesozoic, Paleozoic and the Precambrian time. They all were separated by mass extinctions. A mass extinction is when a species has died out completely. The Precambrian time is the time when the earth began. Scientists think that the early earth was very different than it is now. They think that the atmosphere was made of gases such as water vapor, carbon dioxide, and nitrogen. Cyanobacteria is the simplest living organism that uses the sun’s energy to produce its own food. The first cyanobacteria began to release oxygen gas into the oceans and air. When there was enough oxygen it formed a new layer of gas in the upper atmosphere, it was called…show more content…
Instead of focusing on an individual species, a macroevolutionary view might require that we look at the tree of life and its diversities. Macroevolution refers to the major evolutionary changes over time. The small or microevolutionary changes occur by recombining existing genetic material within the group. As Gregor Mendel observed with his breeding studies on peas, there are natural limits to genetic change. A population of organisms can vary only so much. Microevolution is simply a change in gene frequency within a population. Evolution at this scale can be observed over short periods of time between one generation and the next. The frequency of a gene for pesticide resistance in a population of crop pests increases. Such a change might come about because natural selection favored the gene, because some non-resistant genes mutated to the resistant version, or because of random genetic drift from one generation to the next. The change is due to four different processes: mutation, selection (natural and artificial), gene flow, and genetic drift. This change happens over a relatively short amount of time compared to the changes termed macroevolution which is where greater differences in the population occur. Microevolution over time leads to speciation or the appearance of novel structure, sometimes classified as macroevolution. Macro and microevolution describe fundamentally identical processes on different…show more content…
The Christian worldview does not embrace the theory of evolution. Christianity and evolution have different worldviews. We as Christians believe that God created the universe. Evolutionists do not agree that God had anything to do with the creation of the universe. The origins of man cannot be scientifically tested or verified since none of us were there. The reason that evolution cannot be proven is that true science is based on observation and testing. The theory of evolution should be considered to be a philosophy, not a scientific theory, but the fact that God created everything cannot be tested either and creation scientists readily acknowledge this fact. Nevertheless, the theory of evolution which is based on unobserved, untested ideas is no more reasonable than the creationist’s belief in God. From the perspective of a scientist who believes that evolution is responsible for all the diversity of life on earth, all organisms are descended from a common ancestor. Secular scientists present Darwin’s scientific observation of the changes in beaks of Galapagos finches as proof for the evolution of an animal kind into another. The creation scientists readily admit that there exist differences between finch beaks and they agree there is adaptation or variation within a species. To extrapolate that this observed variation translates into proof of evolution is not conclusive science. Operational science is science where
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