Download Human Origins

Brenda Hernandez
Human Origins
10:00-11:20 MW
DARWIN'S FINCHES AND NATURAL
SELECTION
Charles Darwin was born on February 12, 1809 he was an English naturalist who gained
great fame for the development of his theory of evolution by natural selection or the well known
Darwin's finches theory. (EGS) The theory of natural selection that he develop when he saw the
birds on the Galapagos Island during his famous voyage around the world in 1831-1836,
change his thinking about the origin of new species specially after he read three different books
by Lyle's principles of Geology, Paley's Natural theology and Malthus's principles of population
that change his view about life. (Schaefer) Darwin wondered about the different shapes of bird
beaks from island to island, (University) he collected and studied the different species later by
this observation he started to develop his theory of evolution by natural selection and came out
with different assumptions.
Charles Darwin's finches are compose of a group of 13 distinct species that live in the
Galapagos Islands, each inhabits a different island, each of them evolve from a single ancestor,
presumed have arrived on the islands several million years ago (PBS). Each bird has a different
diet and has unique characteristic which was develop through evolution. Some of the
characteristics of the finches for example are: the cactus finch (Geospiza conirostris) which has
a long beak that can reach the blossoms, the large ground finch (Geospiza magnirostris) has a
long beak adapted for eating seeds that are buried under the soil, and lastly the large tree finch
(Camarychus psittacula) has a beak that is similar to a beak of a parrot which is suited for
stripping bark to find insects. (PBS, Evolution)
Many experiments have been done either by students at school or real scientist, if a
hypothesis is propose should allow the possibility of falsification, when we do this experiments
again we are not saying that they are wrong, but sometimes it might need to be modified or to
find new information, Darwin in a test tube was an article publish by Jason Bardi base on a
experiment develop by the Scripps Research institute conducted by Sarh Voytek and Gerald
Joyce, they replicated the experiment but they use RNA molecules that continuously evolve.
(Bardi) Another experiment was done by Molecular Biology and evolution and they used blood
samples from the birds in St. Lucia in Ecuador, (OXFORD Univerity Press) and by the
Northeastern University their question was How did all the finches on each different island come
to have the same type of beak and they show the materials that they needed, procedure and a
discussion (Natural Selection – Bird Beak ) unfortunately the results aren't shown however it has
data,
Hypothesis:
My prediction is that people who have tongs and chip-clips as beaks will be more
successful because, tongs and chip-clips are easy to handle and can grab things more easily.
Those who were given clothespins and chopsticks will be less successful because clothespins
tend to be hard to handle and open. Chopsticks can be a challenge to a person who is not so use
to them, our society uses forks, spoons and knives to eat and this can be a disadvantage for this
experiment.
Materials needed:
(1-8 were used as beaks)
1. Tongs
2. Chips clips
3. Long hairclips
4. Binder clips
5. Tweezers
6. Clothes clips
7. Chopsticks
8. Small hairclips
9. Sunflower seeds
10. paper cups
11. Timer (60 sec)
Procedure:
We begin the experiment with 30 students; the classroom consist of 4 columns with 8
rows, the teacher began by hanging us the first seven things mention in the list above that were
distribute among the 30 students, than she spread seeds across the tables(the number of seeds is
uncertain she didn't measure it). On the next page you will be able to find the amount of beaks
that we started the experiment with. After she spread the seed she gave us instructions on how
the experiment was going to work:
i.
ii.
iii.
iv.
We were not allowed to grab more than one seed at the time.
We had to deposit the seed in the cups.
If we run out of seed we had to go to other environments.
We only had 60 seconds to complete the experiment.
After the 60 seconds run out we had to stop and count how many seeds we collected, later
she choose 3 people who had the least seeds and 3 people who had the most seeds she ask who
had 10 seeds or less, than students would raise their hands and if no one had less than 10 than the
number started to go up until she had 3 people with the least seeds or 3 with the most seeds
Example: If you look at the chart below you can see that we started with 3 tongs and in round
one we had 5, this number was able to increase because, the three winners at the begging were: 2
people with tongs and 1 with tweezers, the 3 "losers" were: 2 people with clothes pins and 1 with
binder clips. Two of the "losers" were given a pair of tongs each and one was given a pair of
tweezers, as you can see the two clothes pins and the binder clip were eliminated. This
represented natural selection, how some traits are loose because they aren't helpful or they evolve
some new kind of skill or trait.
We did this about six times counting the beginning and after each round the three winners
and "losers" were selected, the "losers" were given a new peak, each round lasted 60 seconds.
Before round two the teacher said that a mutation had happen and one person who had tongs as a
peak was given a small hair clip instead, a pair of tongs was eliminated.
RESUTS
At the beginning of the experiment we started with 3 pairs of tongs, 5 chip clips, 5 long
hairclips, 3 binder clips, 5 tweezers, 4 clothes pins, and 5 chopsticks. After the 60 seconds run
out each of the students counted their seeds and we had three winners and three "losers" a
binder clip and 2 clothes pins were taken out and were replace with 2 pairs of tongs (two people
with tongs won) and a pair of tweezers( a person with tweezers won).
On the second round two pairs of tongs were gain and because of a mutation small
hairclips were added a clothes pin and two pairs of chopsticks were taken away, on the third
round a chip clip was acquire along with a pair of chopsticks however a pair of tongs and a
binder clip was lost. On round four a pair of tongs was add and a chip clip was lost. On the last
round a chip clip was obtain and a pair or tongs was taken out, most of the other peaks remain
constant their change wasn't as much as the other peaks surprisingly those types of beaks were
able to remain throughout out the experiment, below you can find some data that would confirm
he results.
NATURAL SELECTION DATA SHEET
Beak Types
Tongs
Chip-clips
Beginning
Round 1
Round 2
Round 3
Round 4
Round 5
#:3
#:5
#:7
#:6
#:7
#:6
Freq:10
Freq:16.67
Freq:23.33
Freq:20
Freq:23.33
Freq:20
#:5
#:5
#:5
#:6
#:5
#:6
Freq: 16.67
Freq: 16.67
Freq: 16.67
Freq:20
Freq: 16.67
Freq:20
#:5
#:5
#:5
#:5
#:5
Freq: 16.67
Freq: 16.67
Freq: 16.67
Freq: 16.67
Freq: 16.67
Freq: 16.67
#:3
#:2
#:2
#:1
#:1
#:1
Freq:10
Freq:6.67
Freq:6.67
Freq:3.34
Freq:3.34
Freq:3.34
#:5
#:6
#:6
#:6
#:6
#:6
Freq: 16.67
Freq:20
Freq:20
Freq:20
Freq:20
Freq:20
#:4
#:2
#:1
#:1
#:1
#:1
Freq:13.34
Freq:6.67
Freq:3.34
Freq:3.34
Freq:3.34
Freq:3.34
#:5
#:5
#:3
#:4
#:4
#:4
Freq: 16.67
Freq: 16.67
Freq: 16.67
Freq: 13.34
Freq: 13.34
Freq:13.34
#:0
#:0
#:1
#:1
#:1
#:1
Freq: 0
Freq: 0
Freq: 3.34
Freq: 3.34
Freq: 3.34
Freq: 3.34
Long hairclips #:5
Binder clips
Tweezers
Clothespins
Chopsticks
Small hairclip
PIE CHARTS
Beginning
Round 2(middle)
3%
17%
Tongs
Tongs
10%
3%
Chipclips
Chipclips
10%
23%
Long hairclips
16%
13%
Binder clips
Binder clips
20%
Tweezers
Tweezers
17%
17%
Clothes pins
17%
7%
17%
Chopsticks
10%
3%
14%
Tongs
20%
Chipclips
Long hairclips
Binder clips
20%
20%
Tweezers
Clothes pins
Chopsticks
17%
3%
Clothes pins
Chopsticks
Small hair clips
Round 5 (last)
3%
Long hairclips
Small hair clips
CONCLUSION
As we were able to see on the data and charts above tongs and chip clips that were use
in the experiment as beaks, were the once that were the most successful, part of this was
because, tongs and chip clips are easy to handle and most people in our population are use to
this kind of artifacts. If the experiment had been done with a different population where perhaps
they have a greater advantage over chopsticks the results would have been differently. In this
experiment chopsticks remain constant most of the time however clothes pins almost extinct,
not all people with this kind of beak was able to survive,. The results above prove that my
hypothesis was correct, tong and chip clips were a favorable trait to have in order to collect the
most seeds, clothes pins was an unfavorable trait; chopsticks did not do so bad of a job the
people who had them were able to state in the experiment.
Some possible factors that could of affect the results of the experiment would have been
if for any reason some of the items (beaks) broke in the middle or in the process of the
experiment, this would have created a big disadvantage the results would be question. Another
factor that affected this experiment was when we run out of seed standing up and look for seeds
to steal was a huge disadvantage, we wasted seconds which means that we were able to
collect less seeds.
The replication of an experiment is very important, when an experiment is replicated
scientists verified the experiment, they are able to understand the experiment more and see if
the hypothesis provide is valid, if for some reason the results are not the same, scientist can
modified or ultimately discard it, verification is probably the second most important step in order
to make an experiment perfect.
DISCUSSION
The scientific method is a way to ask a scientific question and answer it. There are
several steps involve in the scientific method, the first step is to ask a question, any kind of
questions can be ask, they don't necessary have to be related to science because anyone can use
it. The second step is to explore or gather some existing information; you can find this in books
or journals to determine what other people have done to resolve the issue. (Jurmain) The next
thing that you have to do is created a hypothesis. A hypothesis is an educated guess; here you
will write what you think will happen in the experiment, what the results will be.
Next you will have to test your hypothesis by creating an experiment, you have to collect
information or data that later can be studied or analyzed, after you have collected all the data
necessary you can draw a conclusions, when you write down the steps and materials you have to
be really specific, you must write everything you did and how you did it, what kind of
measurements did you use if any so that later your experiment can be replicate. The last step is to
prove whether your hypothesis was supported or not and you must explain the reason why is
correct or why not (Jurmain).
The scientific method is not only used by scientist many other fields used it such as a
physiologist; they use the scientific method when they want to conduct a research. We con
used the scientific method in our everyday life, a judge can use the scientific method or justice
when they are trying to solve a case or when he's trying to find the person guilty or incent, the
scientific method can be use by anyone in every situation because is very helpful.
In this activity we were able to use the scientific method, we had to create a hypothesis
of what we thought was going to happen with each of the beaks that we were given, we
collected data after each round and we also made an experiment in which we participated, it
show us how a hypothesis can be proven either right or wrong and now finishing it by writing a
lab report gave us an idea of what really goes into the process and how the process is built from
the beginning to the end of the experiment.
Evolution by natural selection, this idea was first introduced by Malthus but later Darwin
realizes that natural selection was the key to evolution. (Jurmain) Darwin then develops an
explanation base on what he understood. The process states the following: (1) species can
produce offspring faster than food supply, which can ultimately lead to completion, (2) individual
with favorable traits have an advantage to survive and reproduce more, leave more offspring,
(3) Those species with favorable traits will inherit them to later generations and (4) Those
species with the favorable traits will become more common and will eventually create a new
species.
This experiment supported the theory of evolution by natural selection because, during
the experiment we were able to see how people who had beaks that weren't very favorable
were eliminated in each round and were given the new beaks. The beaks that were given to
them were those beaks that were the most favorable or successful in that particular round, when
this happen it represented an evolution in their beaks that the birds had to acquire, this
experiment show exactly how and why evolution happens.
BIBLIOGRAPHY
Bardi, Jason. News & Views. 4 May 2009. website. 29 January 2015.
EGS, European Graduate School. The European Graduate School. 1997-2012. Biography. 29
Januray 2015.
Jurmain, Kilgore, Trevathan. Human Orings Evolution and diversity. Ohio: cengage learning,
2011-2013. Book.
Natural Selection – Bird Beak . 2012. 4 February 2015. <http://www.stem.neu.edu/programs/reseed/activities-and-labs/natural-selection-bird-beak/>.
OXFORD Univerity Press. 2015. 4 February 2015.
<http://mbe.oxfordjournals.org/content/18/3/299.full#sec-2>.
PBS. evolution. Ed. WGBH Boston. 2001. WGBH/NOVA Science Unit and Clear Blue Sky
Productions . 4 February 2015.
<http://www.pbs.org/wgbh/evolution/darwin/origin/finches.html>.
—. Evolution. Ed. WHBH Boston. 2001. WGBH/NOVA Science Unit and Clear Blue Sky
Productions. website. 4 February 2015.
<http://www.pbs.org/wgbh/evolution/educators/course/session4/elaborate_b_pop1.html>
.
—. evolution Adaptive radiaiton: Darwin's finches. Ed. WGBH Educational Foundation. 2001.
WGBH/NOVA Science Unit and Clear Blue Sky Productions. 4 Februaty 2015.
<http://www.pbs.org/wgbh/evolution/educators/course/session4/elaborate_b_pop1.html>
.
Schaefer, Melissa K. In class lesson. 2015.