Monthly Archives: September 2012

History

I learned that history is not always accurate. When things are seen or heard, each person interpretes it differently, and when a historian writes a novel or book based on the event, it will be from what he/she has interpreted, which is not the same as someone else. Therefore the word history itself describes what it is “his” and “story”, meaning that it is from one person’s view and can differ from many other people’s views.

Differences between Natural and Human Sciences

Both sciences have similar methods in that both observe, hypothesize, experiment, gather data, analyze the results and hope to create a law from this. However, the key difference between these two sciences is that while natural sciences can make predictions, human sciences cannot. There are many other differences between these two sciences as well. Firstly, while natural sciences look at the mechanical causes and effects of subjects, human sciences look at the purpose and meaning behind human behavior. Secondly, natural sciences are more objective than human sciences. Third, natural science experiments are done mostly in laboratories while human sciences are not. These are only some of the differences between these two sciences. While there are differences, there are also similarities such as the types of variables and the importance of replicating results.

D.3c: Human Evolution & Culture

Data-based question: cranial capacity and diet 

1a. As the cranial capacity increases, so does the percent of energy allocated to the brain. While most of these species show a linear relationship with each other, modern chimpanzees and p. boisei do not.

1b. If the brain size is bigger there is more energy allocated as cranial capacity, therefore higher dietary energy is necessary. Also, the communication and knowledge is also better ,therefore information necessary for dietary energy is easier to understand and learn.

2a. By looking at dental records such as the teeth, it can be inferred what food was consumed. Also, if we try to find human teeth marks on animals, we can see if they were consumed.

2b. Eating meat can provide more energy and proteins to hominids. This energy can then help increase the size of the brain.

3a. As the brain size increases, so does the relative diet quality. Humans have the highest brain size as well as dietary energy.

3b. Humans may be above the trend line if they formed a species in a different niche and took advantages of the resources that were provided.

D.3b: Hominid Evolution

Questions on page 300 

1. According to the figure, the earlier known members of the Homo genus is Homo ergaster and Homo habilis.

2. Homo neanderthalensis and Homo floresiensis were two members of the Homo genus that were alive at the same time.

3. K. rudolfensis, H. ergaster, P. robustus, P. boisei are four hominids that may have been alive at the same time 2 million years ago.

Thinking about science: genetic and cultural evolution

Forty thousand years ago our ancestors met another type of humans known as the Neanderthals living in Europe. Such collision could have happened many times before as well. Several species of humans coexisted in Africa and then spread around the globe, meaning other kinds of humans such as H. erectus. However, the European accounted with Neanderthals was probably the last meeting between humans.

D.3a: Primate Evolution

Hominid evolution

Humans are considered primates due to their opposable thumbs and toes, fingernails, forward-facing eyes, rotatable shoulder joins, and color vision. These are features that are used as adaptions of life in trees. In fossils, there is evidence that of many species that once existed may never be uncovered. Early hominids did not practice rituals such as burials so bones would have been scattered and therefore scavenged. Paleoanthropology is a data-poor science. Fossils finds such as the disputed Homo floresiensis can lead to changes in theories of human evolution. Fossil records suggest that at various stages of hominid evolution, some species of hominid may have coexisted.

Data-based question: dating fossil using radioisotopes 

1a. 1/4–> 25%

1b. 1/8–> 6.25 %

2. about 37.5% of the atoms

3. 40K has a half life of 1250 million years, therefore it would be hard to find accurate data for species that are less than 100000 years old.

4a. Carbon 14 can be used to give accurate ages of specimens less than 10000 years old.

4b. This radioisotop is useful for this purpose as its half life is not very long, therefore would give useful data for specimens less than 10000 years old.

TOK experiment

Orignal Knowledge Question: To what extent can we trust the conclusions drawn from human science research?

Question for Experiment:  To what extent are our preferences affected by certain claims?

Experiment Knowledge Issue: Bias

Knowledge Issues/ Countries

To what extent do the intended uses of research in human sciences affect the certainty of the claims made?

From these articles, I learned that it is hard to justify the data that is used to measure happiness in a country as people have different criteria to measure their own happiness. Also, it is easy to manipulate the measurements to get the answers you want. For instance, if you want to show that the school is more diverse, you would find ways to make your data come out as smaller percentages of Japanese people so that it seems there aren’t that many people of one population. Therefore, certainty may not be achieved as the data can be manipulated.

Who won the Olympics?

Knowledge claims

  • Precise language is necessary in the articulation of knowledge claims in order to (achieve)(increase)

Human Science Methodology (Explanation, Justification, Evidence = Measure)

  • Qualitative data (can be)(is often) converted into quantitative measures
  • Operationalizing variables allows a researcher to manipulate and isolate effects
  • how we measure a phenomena or object can affect our conclusions about it

Quantitative Measure 

  • may appear to be more objective but they may not be

D.2d: Species and Speciation: Macroevolution

Polyploidy 

Polyploidy is a form of sympatric speciation that does not require geographic isolation. It has two sets of homologous chromosomes occurs most in plants due to an error in meiosis. The formation of even a single polyploid individual, if fertile, could be a speciation event if the plant reproduces asexually or by self fertilization. The ability to reproduce on their own enables such polyploid parents to produce a breeding population An example of this is modern wheat.

D.2c: Species and Speciation: Sympatric Speciation

Data-based question: lacewing songs

1.Both of the songs range between -4 and 4 at a certain point. However, a constantly goes from -4 and 4 to 0 then back to -4 and 4 as the range (repeated), b starts at a range of about 0, goes up to -4 to 4 once, then starts to decrease its range gradually.

2. There are differences in mating calls as it leads to speciation. The types of Lacewings will own listen to the mating call that attracts them, and this will differ between a and b. Due to this difference, the types of lacewings will be reproductively isolated, leading to speciation.

3a. Allopatric speciation occurs due to geographical isolation. This could have occurred if the mating calls caused mating to occur in different environments. Soon, this would lead to new habits or behaviors of lacewings to better adapt to their own environment, leading to geographical isolation.

3b. Sympatric isolation occurs within the habitat. In this, the mating call of a and b could overlap, however, due to different behavioral patterns and different niches within the habitat, speciation occurs.