Shark Bay Stromatolites

The author and his colleagues specifically chose to focus on 375 million year old rocks in their search for fossils because this was the time frame that provided fish that would be useful to study from. The 385 million year old rocks provided fish that look too similar to the ones we have now and the 365 million year old rocks have fossils that don’t resemble fish. The 375 million year old rocks, however, provide fossils that show the transition between fish and land living animals.

Fossils grant us opportunity of understanding about species which no longer exist on Earth- that are extinct. The prehistoric remains inform us about plants and

In the following space, explain the role of fossils in developing the Geologic column. Your explanation must be between 200 and 300 words.

From both the title of the chapter and the introduction by Dr. Shubin, this chapter begins with a focus on teeth. Because the function of teeth is to break down food before it enters the esophagus, the different shapes of teeth can represent many different things about the organism it belongs to including what type of eater it was (carnivore, herbivore, or omnivore). Teeth are the hardest tissue (not bone) in the human body and therefore fossilize well. As Dr. Shubin stated in chapter one, there must be many points that permit a fossil to make any kind of scientific conclusion. Obviously, the state of their presence is important, so the fact that teeth preserve well allows for them to be great specimens for analysis. Dr. Shubin and his team analyzed fossilized teeth in areas as different as Nova Scotia and the Arizona desert. Studying different fossils in these diverse regions allowed the team to see that mammalian and reptilian teeth are very different. For example, mammalian teeth differ from organism to organism to fit with the organisms need (Cheetahs that eat only meat will have different teeth than deer who are herbivores) and are replaced only once in the lifetime of the organism while reptilian teeth are usually sharp and are constantly replaced if damaged. These differences allowed scientists to characterize fossils as either a reptile or a mammal. Similar to Tiktaalik discussed in chapter one, the discovery of fossils that were part reptile and part mammal allowed the researchers to see that mammals evolved from reptiles, and further supported the theory of evolution. Further studies yielded even more

The first chapter of the book discusses the way we can use fossil records to study the biological world. Fossils are one of the major lines of evidence we use to understand ourselves. Surprisingly, we are able to discover them with a high amount of precision and predictability. In particular, field paleontologists have it easier than it has ever been before due to the current information age. The physical hunt for important fossils, however, is much like it has always been. Three factors limiting the number of useful fossil sites include rock age, type (whether or not it can preserve fossils), and number of exposed rocks. So, it takes a bit of luck to reliably find fossils. Thankfully, rock

Microbes are bacteria, archaea and eukaryotes. The earth was formed 4.6 million years ago. And a few million years later, by 3.5 billion years ago, earth was already inhabited by a diversity of organisms. The earliest organism is Prokaryotes and within the next billion years, two distinct groups of prokaryotes called bacteria and archaea diverged. Eukaryotes cell evolved from a prokaryotes community, a host cell containing even smaller prokaryotes .The microbial world accounted for all known life forms for nearly 50 to 90% of Earth's history. We are still researching microbial organisms today in marine environment, extreme environments. A microbial observatory is an NSF-funded project dedicated to the discovery and characterization of novel microorganisms and microbial communities of diverse

Stromatolites and thrombolites are formed in very specific environments with very specific triggers for their precipitates. Bodies of water that have developed high salinity (hypersaline) such as Hamelin pool in Shark Bay Australia and Lee Stocking Island in the Bahamas are ideal environments for stromatolites. Hamelin pool is twice as salty as the open ocean and this does not provide a suitable living environment for snails or other organisms that would consume algae thereby leading to a flourishing population of cyanobacteria. The cyanobacteria population started blooming with little deterrence as far back as three and a half billion years ago as shown in fossil evidence. Although the stromatolites in Hamelin pool are not nearly this ancient (they age at about three thousand years

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

Fossils can tell us a lot about the organisms that came before us. They are useful in dating when certain evolutionary aspects were achieved in our past as we developed. Fossils have allowed us to explore past civilizations and gives a major glimpse into the past. Fossils are a very important part in the advancements of biological evolution. Biological evolution is the way scientists work to understand the past, and to piece the puzzle of our ancestry together to understand how we have evolved over time. Fossils are a large part of this field because it allows us to see physical evidence of links between different species, and common ancestry between these species. By finding fossils of civilizations that were sequential, we can compare bone

Cyanobacteria are ill-shaped relatives of bacteria, contrary to the name, that are aquatic microörganisms, which often grow in colonies that are large enough to be seen with the naked eye, that perform photosynthesis to make their own food. Since they make their own food, they are reliant only on the sun, which would make them highly self-sustaining. This would stand to reason as they have the distinction of being the oldest found fossils to date, at about 3.5 billion years of age.

The fossil record provides a unique view into the history of life by showing the forms and features of life in the past. Fossils tell us how species have changed across long periods of the Earth’s history. For instance, in 1998, scientists found

Many things can be learned from studying fossils. Studying fossils can tell us anything from where an organism may have lived and how long ago an organism lived. Also, scientists can even learn what an organism consumed while it was alive if there are coprolites

The nature of the original fluid content of ancient sediments is just frequently indicated by observing the associated trace fossils and bioturbation structures. The consistency of the substrate is based on the grain size, sorting, water content, organic matter content, and composition. Substrate can be classified as soupground, softground (for muds and silts) and loosegrounds (for sands and gravel), firmground and hardground, with increasing compaction,

These techniques led to the discovery of the boundary between the two eras. A single thin layer of clay found within predominantly limestone rocks established this. By comparing the marine life found in, above, and below the clay, the marine life, like the dinosaurs, had been terribly affected by the extinction event. The percentage of life in the upper layers was dramatically lower than that in the lower. This was far more compelling than what was suggested by dinosaur’s fossils.

Beginning about 1850 Ma, we find acritarchs, spherical microfossils with thick and complex organic walls. They are probably dinoflagellates that spent most of their life floating in the plankton.