Question

1)One of the greatest advances in early paleontology was the recognition by Cuvier and others that “the history of life…was long, mutable, and full of fantastical creatures that no longer existed”this passage relates to the theory of evolution and natural selection

How did biostratigraphy help inform the insight above?

2)Fully explain the chain of events that leads to low calcium ion availability in the oceans.

Answer 1

1) Biostratigraphy originated in the 19th century, where geological scientists recognized that the correlation of fossil assemblages between rocks of similar type but different age decreased as the difference in age increased. The method was well-established before Darwin’s theory of evolution through natural selection. The Biostratigraphy focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.

2). Calcium occurs in water naturally. Seawater contains approximately 400 ppm calcium. One of the main reasons for the abundance of calcium in water is its natural occurrence in the earth's crust. The calcium is the various systems have been circulated and maintained with the help of the calcium cycle. It occurs in two phases i) dissolved form and ii) solid phase. There are different sources through which calcium ions supplied into the ocean water. Calcium ions generally forms insoluble structures like calcium carbonate and calcium silicates. In the ocean ecosystem, calcium is also utilized and consumed by marine organisms for the production and growth of their body parts like shell, bones and teeth. Calcium moves through these different media as it cycles throughout the Earth.