These are Geology questions about the timeline please help! Please answer the fo

Question

These are Geology questions about the timeline please help!

Please answer the following questions: A. Explain what might happen if one was to go back in time to the lower Precambrian and prevent photosynthesis from evolving? Please offer specifics. B. There is a lot of empty space on the timeline. Generally speaking, what is happening during these empty spaces? Please offer specifics C. Using data from your timeline, comment on this statement: "A long time ago humans had to fight off marauding dinosaurs. D. If humanity finds an Earth-like planet around a Sun-like star, which is 109 years old, should we expect to find intelligent life? Why or why not? Be specific.

Explanation / Answer

a)

3.4 billion years ago first photosynthetic bacteria fomed, they absorbed near-infrared rather than visible light and produced sulfur or sulfate compounds rather than oxygen. Their pigments (possibly bacteriochloro­phylls) were predecessors to chlorophyll.

2.7 billion years ago -- Cyanobacteria
These ubiquitous bacteria were the first oxygen producers. They absorb visible light using a mix of pigments: phyco­bilins, carotenoids and several forms of chlorophyll.

2.4–2.3 billion years ago -- First rock evidence of atmospheric oxygen.

If at all this process of photosynthesis did not occur, any life form that evolved out and sustains its life based on oxygen could not have formed. So basically from our knowledge of such life forms only a few non photosynthetic microorganism would have been the part of earth’s life forms. Hence all this biodiversity and life forms and landscapes are in way or other products and by-products of photosynthesis.

Another possibility of an environment where photosynthesis did not occur is of a habitat where life could directly use CO2. But that would have been a completely different geological biological process. The Earth would still have an iron-rich ocean. May be air would have more carbon dioxide, or all of the carbon dioxide would have been locked away in carbonate rocks and we would have an entirely nitrogen atmosphere. Life would be found only in geothermal vents where it is possible to get energy without relying on the sun. There would be no "advanced" multicellular life such as the kinds that we are familiar with.

b) If the empty spaces on the timeline is on a genralized timescale , it may be due to unknown data , or the data was not sufficient enough to decribe the process during that geologic time period. NO IMAGE . If an empty space is found on a loca stratigraphic record it must be an unconformity , a period of continued erosion or non deposition.

c)

The fifth mass extinction ended the era of dinosaurs. These terrific predators and there herbivores relatives evolved about 225 million years ago in Triassic period. After 160 million years marauding on every earth continent possible then, they quite suddenly disappeared from subsequent fossil record in the Cretaceous period. The earliest of the primates evolved only after this period in the Cenozoic known as the age of mammals. The apes started to flourish in Miocene that is 122500000 years later in geologic history. The near Human species was observed in Pliocene much later after this. Hence humans being had to fight off marauding dinosaurs is shear fantasy.

d) If the found out planet had gone through all the chance events and process that earth went through , by the time of 1 billion years not much of life forms would have been formed. 1 billion years is the time when earth have just cooled , the haeden era has just finished and may be a few microscopic organism and lower prokaryotic life forms have been developed. The chances of animals with intelligence is very low or nil . ( taking earths time scale anologous to the new planet)

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