Question

In: Biology

This week we have been learning about the methods archaeologists and paleontologists use to reconstruct the...

This week we have been learning about the methods archaeologists and paleontologists use to reconstruct the past. Now it’s time to get creative and apply this new knowledge to the present day. This is going to involve a little bit of research and creativity on your part. Pick a room in your house, apartment, dorm, or alternative domicile. If you walked out the door today and your room remained untouched for 100, 1,000 or 50,000 years, what would be left for archaeologists in the future to analyze?

Think about the types of materials that make up your room and how they will degrade over time. Do you have metal, ceramic, glass, and wood in your room? Did you leave chicken bones in your trash or canned soup in the pantry? What types of methods that we employ today, would researchers use to “date” your room? For example if you have ceramic dishes an archaeologist might use thermoluminescence dating to try to figure out when they were made.

Post a paragraph discussing a few of the main things that you think might still be around for archaeologists to find, and include how researchers might identify how old they are. You can insert pictures or drawings in your post if you would like too. In addition, think about what types of issues researchers in the future could have trying to analyze materials from today?

Solutions

Expert Solution

This is a really interesting question with a lot of scope of creativity. I choose to pick my study which has a quaint set-up, which includes a table with an attached cabinet full of books. On my table, I keep my laptop, speakers and the wireless mouse. The room also has a separate cabinet which show cases certain trophies won during my high school activities, ceramic dishes from my grandmother, a teracotta clay pot, my coin collection from various countries, a conch and a coral which I bought during a vacation to a sea beach, and a small container in which my mother carefully kept my first milk teeth when it fell off. My study room also boasts of a small window, with two pots full of flowering Petunia plants. The last day I remember, I was busy with some background research on my laptop, while some chocolate wrappers lied astray on my table. I felt thirsty, and therefore had to fetch a bottle of water before I could resume. So I left my room.....

100 years later..... Archaeologists find there way into my room and come across several things, which they can 'date' to find the exact age of the articles and also of my room. They can use various methods of dating (radiocarbon or luminescent) to find the exact age of the samples collected from the room.

1) Radiocarbon dating: This will help to determine the age of a sample which has organic material. This method uses the properties of a radioactive isotope of carbon (14C, radiocarbon). The cosmic rays in our atmosphere interact with atmospheric nitrogen constantly generating radiocarbon or 14C, which then forms carbon dioxide by reacting with atmospheric oxygen. This CO2 is incorporated by plants during photosynthesis and by animals when they eat the plants. Upon death of these organisms, this carbon exchange comes to a stop. So the  14​C that had accumulated starts decaying from this time point by radioactive decay and the resultant 14​C concentration in a sample decreases. Therefore older samples have less 14​C content. The half life of 5730 years of 14​C allows calculation of age to approximately 50000 years ago.

Therefore all samples, which may have an organic or carbon content can undergo this dating method. Using this process, the age of the table, the books, the conch, the coral, and the soil within the pot, can be easily approximated. Precisely my age, can also be guessed from radiocarbon dating using my milk teeth sample.

  • Wood from the table, pages from the books, and the soil sample would be rich in cellulose and lignin. Cellulose hardly exchanges carbon with the environment, so it is the best component for carbon dating. The soil sample will be contaminated with the remains of the Petunia plant, which has possibly degraded over the span of 100 years, so the age of the soil and plant cannot be precisely determined.
  • Shells, conches and corals from marine organisms are a rich source of carbon, as they are composed of calcium carbonate which is present as aragonite or calcite, or many a times as a mixture of both. Besides, conchiolin, an organic protein found in shells, constitutes about 1-2% of the shell material and is also a potent source of radiocarbon in such samples.
  • Soil contains organic material also, but contamination results in disorienting results and approximations. Hence the soil samples can be seived to separate the organic materials from the soil to fine tune the analysis. Again in this case, the petunia plants' age cannot be distinguished from that of the soil.
  • Tooth enamel is a good sample to estimate the amount of radiocarbon present and can be an accurate indicator of a person's year of birth. Since there is no turnover or decay of enamel once it is formed, 14C levels in the enamel typically represent the atmospheric 14C levels at the time of its formation. Therefore an analysis of my first milk tooth can accurately predict the year when I was born.
  • Radiocarbon dating can be achieved either by using 1) a gas proportional counter or a liquid scintillation counter, which counts the number of beta particles being emitted from the sample in a given time period; or 2) accelerator mass spectrometry (AMS) which counts the atoms of 14C and 12C in a sample, thereby directly determining the 14C/12C ratio.

2) Luminescence dating: This determines how long ago the mineral grains in a sample were exposed to sunlight or heat for the last time. Radioactive isotopes of potassium, uranium, thorium, and rubidium can be found in trace amounts in sediments and soil samples. These isotopes slowly decay with time, while the ionizing radiation they emit is absorbed by mineral grains in sediments for example, quartz and feldspar. The ionizing radiation is trapped as charges within "electron traps", which are structurally unstable. If these mineral grains are stimulated using either by light : a) blue or green (optically stimulated luminescence, OSL), b) infrared (infrared stimulated luminescence, IRSL), or heat (thermoluminescence, TL), a luminescent signal is emitted as the energy from the unstable electron traps are released. The intensity of the signal depends on the amount of excitatory ionizing radiation had been absorbed at the time of burial and the inate properties of the mineral.

The ceramic dishes, the trophies and the coin collection are suitable samples for luminescence dating.

  • Crystalline minerals, like that preset in the ceramic dishes, emit a weak luminescent signal when heated. Thermoluminescent dating is a good option for such samples.
  • The trophies and coins are made up of metal and can serve as samples for OSL. But since trophies and coins usually have a date or year listed on them, I think the archaeologists will prefer absolute chronometric or calendar dating for such items. Such absolute dating can also be done for the food items, such as from the left over chocolate wrappers, to estimate the age of the chocolates or when they were manufactured.

3) Potassium Argon dating: Potassium-40 is the radioactive isotope of potassium, that eventually decays into argon-40. This dating nethod is based on the measurements of the product potassium-40 from potassium into argon-40. The half life of potassium-40 is 1.3 billion years. Potassium is generally found in rocks, clay minerals, micas. The teracotta clay pot showpiece may serve as a suitable sample for such a dating method, and the age of the material of this pot may be approximated by employing this method.

The Researchers or Archaeologists in future may face certain issues in trying to analyze the above mentioned materials.

1) The book pages and the wood of the table are susceptible to termites, which eat up the material and make it porous such that the integrity of the sample is lost. So enough sample cannot be available always.

2) Humic acid and carbonate are the two common contaminants that should be removed before radiocarbon dating. but pretreatment to remove these contaminants also destroy the structural integrity of the sample and the overall material volume for further analysis.

3) Soil samples are rich in organic material, but humic acid contamination can result in dissatisfying results. As previously mentioned, the soil samples need to be seived to enrich the organic components for better analysis.

4) the samples to be used for luminescent dating should be absolutely away from light or heat source, which is sufficient to excite the electron traps to emit photons. Even a brief exposure to light (1-100 seconds) is sufficient to initiate thermoluminescence or OSL, as the dating clock is revised.


Related Solutions

this week we are learning about language and cognitive development. Psychologists have been debating for quite...
this week we are learning about language and cognitive development. Psychologists have been debating for quite some time about whether it is nature (heredity) or nurture (our environment) that influences our development and behavior. Take a look at this video https://www.youtube.com/watch?v=5aNaMlSc3Ag&list=PLC6B610F325F65635 and share your perspectives on what you believe was most influential in your own development and behavior.
ECO 226- Week 10  Assignment: The Lemon Market As we have been learning that a  lemons’  market is a...
ECO 226- Week 10  Assignment: The Lemon Market As we have been learning that a  lemons’  market is a market in which adverse selection occurs.   Adverse selection occurs when unobservable qualities are mis-valued because of a lack of information. This is often called a lemons market. How much is a consumer willing to pay for a used car that could be either a lemon or a plum? To determine a consumer’s willingness to pay in a mixed market with both lemons and plums, you...
This week we are learning about atomic physics. At some point we talked about photons. Do...
This week we are learning about atomic physics. At some point we talked about photons. Do some research about photons and share your findings with your group about photons, what they are, why scientists introduced them, and what they do in our understandings of the nature of light.
  This week, we are learning about communicable diseases or those diseases that are infectious and...
  This week, we are learning about communicable diseases or those diseases that are infectious and the role of public health in detection, treatment, prevention and in some cases eradication. Select a topic from below and post your discussion. Make sure to provide an example in your discussion post.  Discuss the burden of disease caused by communicable diseases and provide an example. Discuss the criteria that are used to establish that an organism is a contributory cause of a disease Discuss the...
This week we are learning about setting a criteria for making a decision based on the...
This week we are learning about setting a criteria for making a decision based on the evidence that is presented. Whenever we make a decision, there is a chance that we are wrong. Convention in Psychology is to accept a 5% risk of being wrong. Do you think that is too high of a risk to take? Why? What costs are there if we are to lower the risk to 1%?
This week we learned about the Foreign Corrupt Practices Act (FCPA). In that learning we saw...
This week we learned about the Foreign Corrupt Practices Act (FCPA). In that learning we saw that a key to reducing the penalty is through keeping books and records that are clean and transparent. Consider this case: A USA public company doing business in Freedonia (a made up name from another Marx Brothers movie!) is compelled to bribe local officials in order to be the first to receive a business license for a certain type of industry there. The competition...
This week we are learning about probability distributions. If you were to explain what these are...
This week we are learning about probability distributions. If you were to explain what these are to a friend how would you explain them? What is important to know about them?
This week, we are learning about the various roles that health professionals play in disease prevention...
This week, we are learning about the various roles that health professionals play in disease prevention and health promotion. Select a topic from below and post your discussion. Discuss the roles that education plays in the development of medicine. Select a medical specialty (e.g. infectious disease), and provide an example of the impact of that medical specialty has in the advancement of public health and improving health outcomes. Discuss the continuum of public health education and identify educational pathways for becoming a public...
This week, we are learning about categorical logic. Provide an example of each type of categorical...
This week, we are learning about categorical logic. Provide an example of each type of categorical proposition. Why is it important to understand categorical logic? Provide some examples of how you could apply these lessons to your personal and professional life.
Java Programming Assignment 6-1 We have covered the “Methods” this week. Apply the concepts that we...
Java Programming Assignment 6-1 We have covered the “Methods” this week. Apply the concepts that we have learnt in class and come up with a “problem scenario” for which you can create a “solution”. Utilize any/all of the examples from the book and class that we discussed. You program should be interactive and you should give a detailed statement about what the “description of the program – purpose and how to use it”. You should also use a “good bye”...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT