Research and write a brief essay describing a specific example of when molecular clocks were used to determine when two species diverged from each other. Explain how this was done.  Your essay should be at least 2 paragraphs long. Remember to write in complete sentences, using appropriate grammar, punctuation, and spelling. Be sure to cite any sources that you use.  Note: If you do not personally believe in evolution, that is fine. However, I still need you to write this essay explaining how supporting scientists believe molecular clocks have been used to show when two species diverged from each other. here is the material. The world around us is full of interactions between different types of matter. All of these interactions are caused by one of four fundamental forces; gravity, electromagnetism, weak nuclear force, and strong nuclear force. Gravity Gravity is the attractive force felt between any two objects. The magnitude of this force is determined by the mass of the objects and the distance between them. While there is gravity between small items like you and your best friend, your masses are so small that this force is undetectable. This force is responsible for the Earth orbiting the Sun, objects falling to the ground, and the ocean tides.  Electromagnetism Electromagnetism is the force responsible for the attraction and repulsion between charged particles and magnets. As all of matter is made up of charged particles (protons and electrons), this force is responsible for almost all of the interactions between matter. This force works on the submicroscopic scale (proton and electron interactions) and the macroscopic scale (interactions between people and the things around them). Strong Nuclear Force The strongest of the four fundamental forces, the strong nuclear force is responsible for holding together the nucleus of an atom. The repulsive forces between protons is quite large, and this force overcomes that. However, this force is very short ranged and can only be felt within the atom.  Weak Nuclear Force The weak nuclear force is also very short ranged and is responsible for nuclear decay. This force helps unstable atoms to decay into more stable nuclei. The force is responsible for the emission of radiation and energy during nuclear reactions.   Force  Magnitude  Range strong nuclear  strongest force within a nucleus electromagnetism much weaker than strong nuclear infinite weak nuclear much weaker than electromagnetism 0.1% the diameter of a proton gravity weakest force infinite One of the current goals in physics research is the unification of these four forces. Two have them have already been unified, electromagnetism and weak nuclear are together called the electroweak force. There are several theories allowing for The theory of evolution states that organisms change over time. Evolution can mean large changes, such as when species split from each other, and small changes like the shape of a b.

1. Research and write a brief essay describing a specific example
of when molecular clocks were used to
determine when two species diverged from each other. Explain
how this was done.
Your essay should be at least 2 paragraphs long. Remember to
write in complete sentences, using appropriate grammar,
punctuation, and spelling. Be sure to cite any sources that you
use.
Note: If you do not personally believe in evolution, that is fine.
However, I still need you to write this essay explaining how
supporting scientists believe molecular clocks have been used to
show when two species diverged from each other.
here is the material.
The world around us is full of interactions between different
types of matter. All of these interactions are caused by one of
four fundamental forces; gravity, electromagnetism, weak
nuclear force, and strong nuclear force.
Gravity
Gravity is the attractive force felt between any two objects. The
magnitude of this force is determined by the mass of the objects
and the distance between them. While there is gravity between
small items like you and your best friend, your masses are so
small that this force is undetectable. This force is responsible
for the Earth orbiting the Sun, objects falling to the ground, and
the ocean tides.

2. Electromagnetism
Electromagnetism is the force responsible for the attraction and
repulsion between charged particles and magnets. As all of
matter is made up of charged particles (protons and electrons),
this force is responsible for almost all of the interactions
between matter. This force works on the submicroscopic scale
(proton and electron interactions) and the macroscopic scale
(interactions between people and the things around them).
Strong Nuclear Force
The strongest of the four fundamental forces, the strong nuclear
force is responsible for holding together the nucleus of an atom.
The repulsive forces between protons is quite large, and this
force overcomes that. However, this force is very short ranged
and can only be felt within the atom.
Weak Nuclear Force
The weak nuclear force is also very short ranged and is
responsible for nuclear decay. This force helps unstable atoms
to decay into more stable nuclei. The force is responsible for
the emission of radiation and energy during nuclear reactions.
Force
Magnitude
Range
strong nuclear
strongest force
within a nucleus
electromagnetism

3. much weaker than strong nuclear
infinite
weak nuclear
much weaker than electromagnetism
0.1% the diameter of a proton
gravity
weakest force
infinite
One of the current goals in physics research is the unification of
these four forces. Two have them have already been unified,
electromagnetism and weak nuclear are together called the
electroweak force. There are several theories allowing for
The theory of evolution states that organisms change over time.
Evolution can mean large changes, such as when species split
from each other, and small changes like the shape of a bird's
beak. While evolution can not be empirically proven, there is
much fossil and DNA evidence to suggest that it is true.
Click
HERE
to watch a video about the evolution of humans.
Molecular Clocks
The teacher's domain video above states that humans and

4. chimps had a common ancestor several million years ago. This
timeline was calculated using molecular clocks. Certain genes
undergo regular changes to the base pairs in their DNA, such as
one gene that codes for a part of blood changes at a rate of .56
base pairs every billion years. When portions of DNA change at
regular rates such as this they can be used as a type of clock to
show how long ago species diverged by counting how many
base pairs are different. If two species have only 2 base pairs
different in the previously mentioned gene then they must have
diverged from a common ancestor about 4 billion years ago.
Relative Velocity
For anything other than light, the velocity of the source and the
velocity of the observer are both very important.
If a person is riding in a car going 30 mi/hr and a second car
goes by at 40 mi/hr in the same direction, the velocity of the
second car is 10 mi/hr relative to our person in the first car or
40 mi/hr relative to the road. So what you are measuring
relative to is very important.
Einstein's Theory of Special Relativity
One of the assumptions of Einstein's theory goes against
relative velocity in saying that the speed of light always appears
to be 3.0 x 10
8
m/s, regardless of the velocity of the source or the observer.
Basically, nothing can move faster than light. This leads to the
idea of time a fourth dimension and the development of space-
time.
Click
here

5. to join Tim & Moby at BrainPop© as they explore relativity.
BRAINPOP© DIRECTIONS:
1)
Click
“Play Movie”
to begin the movie.
You can click “full screen movie”to watch the movie in a
larger screen.
2)
Check out the
“Q&A”
to review important ideas about
relativity
.
3)
Want to learn some more? Go to
“FYI”
to learn cool facts about
relativity
.
4)
How well do you understand
relativity
? Take the
“Review Quiz”
to find out.
This is not an assessment – just practice! Your score is not
recorded.

6. 5)
Close the window and return here to learn more!
As technology and medicine have advanced, the field of
biomedical ethics has come to the forefront with many
controversial topics, such as the rationing of health services,
euthanasia and the definition of death, and reproductive
technology. The purpose of this section is just to bring to light
some of the questions raised by these advances, not to suggest
answers to these questions.
Rationing Health Services
In terms of health and healthcare there are a great number of
inequities. Some people are rarely ever sick, while others need
constant care just to survive. With a limited number of doctors
is it fair to allow a few patients to take so much of their time,
even if they will never get better? Is it fair that people with
more money and better insurance go to better hospitals and see
better doctors? What about organs? Is it fair for a recovered
alcoholic to get a new liver to replace the one they destroyed
while a child dies for lack of one? These questions have no easy
answers, which is one reason health care law is so difficult to
write. However, these issues impact people and society as a
whole on a daily basis, from the uninsured waiting hours to be
seen in a hospital to patients dieing due to lack of availability
of organs for transplant.
Who Decides What is Death?
Another tough topic is death, and what is clinically dead. With
today's advanced medical technology, life can be sustained in a
body long after brain activity has stopped. Does that person's
family have the right to sustain that life? Sometimes people
return from comas long after their family has been told brain

7. death has occurred. Does science have any right to say what
defines death in a still living body?
Euthanasia (meaning "good death") is on the other end of the
spectrum. While many people support the right for a person to
choose when to end their life, particularly when diagnosed with
a terminal disease, this practice can lead to a slippery slope. If
it is alright to assist the terminally ill with their deaths, what
about the chronically ill, or the severely handicapped? There are
people that believe that those not born "perfect" should not have
been born at all. Some people believe that allowing euthanasia
could cheapen the sanctity of life, and where does that leave
society?
Reproduction
There is also the opposite problem--the argument over when life
begins--brought about by the issue of abortion. A closely
related issue is stem cell research. Stem cells have the
possibility of curing so many diseases, but gathering stem cells
currently requires the death of an embryo. Does the benefit
outweigh the cost?
Click
HERE
for a video about the benefits and difficulties of stem cell
research.
Another issue surrounding reproductive technology is genetic
selection. It may soon be commonplace to be asked what gender
you'd prefer for your child and what color hair you want them to
have. However, genetic diseases could also be all but
eradicated. Even now though, genetic screening brings up some
issues. Who decides what disease are bad enough for a fetus to
not get to be born?

8. Click
HERE
for an interactive with more information about genetic
selection.
Cloning
In 1996 the cloning of Dolly the sheep sparked a wildfire of
debate on the ethics of cloning. While cloning has been used for
years in agriculture, the idea of cloning animals and maybe
eventually people has many concerned. Cloning organs so that
more are available for transplants would be a huge benefit, but
losing the diversity of life by cloning whole organisms could
cause evolutionary problems.
Click
here
to join Tim & Moby at BrainPop© as they explore cloning.
BRAINPOP© DIRECTIONS:
1)
Click
“Play Movie”
to begin the movie.
You can click “full screen movie”to watch the movie in a
larger screen.
2)
Check out the
“Q&A”

9. to review important ideas about
cloning
.
3)
Want to learn some more? Go to
“FYI”
to learn cool facts about
cloning
.
4)
How well do you understand
cloning
? Take the
“Review Quiz”
to find out.
This is not an assessment – just practice! Your score is not
recorded.
5)
Close the window and return here to learn more!
As technology and medicine have advanced, the field of
biomedical ethics has come to the forefront with many
controversial topics, such as the rationing of health services,
euthanasia and the definition of death, and reproductive
technology. The purpose of this section is just to bring to light
some of the questions raised by these advances, not to suggest
answers to these questions.
Rationing Health Services

10. In terms of health and healthcare there are a great number of
inequities. Some people are rarely ever sick, while others need
constant care just to survive. With a limited number of doctors
is it fair to allow a few patients to take so much of their time,
even if they will never get better? Is it fair that people with
more money and better insurance go to better hospitals and see
better doctors? What about organs? Is it fair for a recovered
alcoholic to get a new liver to replace the one they destroyed
while a child dies for lack of one? These questions have no easy
answers, which is one reason health care law is so difficult to
write. However, these issues impact people and society as a
whole on a daily basis, from the uninsured waiting hours to be
seen in a hospital to patients dieing due to lack of availability
of organs for transplant.
Who Decides What is Death?
Another tough topic is death, and what is clinically dead. With
today's advanced medical technology, life can be sustained in a
body long after brain activity has stopped. Does that person's
family have the right to sustain that life? Sometimes people
return from comas long after their family has been told brain
death has occurred. Does science have any right to say what
defines death in a still living body?
Euthanasia (meaning "good death") is on the other end of the
spectrum. While many people support the right for a person to
choose when to end their life, particularly when diagnosed with
a terminal disease, this practice can lead to a slippery slope. If
it is alright to assist the terminally ill with their deaths, what
about the chronically ill, or the severely handicapped? There are
people that believe that those not born "perfect" should not have
been born at all. Some people believe that allowing euthanasia
could cheapen the sanctity of life, and where does that leave
society?

11. Reproduction
There is also the opposite problem--the argument over when life
begins--brought about by the issue of abortion. A closely
related issue is stem cell research. Stem cells have the
possibility of curing so many diseases, but gathering stem cells
currently requires the death of an embryo. Does the benefit
outweigh the cost?
Click
HERE
for a video about the benefits and difficulties of stem cell
research.
Another issue surrounding reproductive technology is genetic
selection. It may soon be commonplace to be asked what gender
you'd prefer for your child and what color hair you want them to
have. However, genetic diseases could also be all but
eradicated. Even now though, genetic screening brings up some
issues. Who decides what disease are bad enough for a fetus to
not get to be born?
Click
HERE
for an interactive with more information about genetic
selection.
Cloning
In 1996 the cloning of Dolly the sheep sparked a wildfire of
debate on the ethics of cloning. While cloning has been used for
years in agriculture, the idea of cloning animals and maybe
eventually people has many concerned. Cloning organs so that
more are available for transplants would be a huge benefit, but

12. losing the diversity of life by cloning whole organisms could
cause evolutionary problems.
Click
here
to join Tim & Moby at BrainPop© as they explore cloning.
BRAINPOP© DIRECTIONS:
1)
Click
“Play Movie”
to begin the movie.
You can click “full screen movie”to watch the movie in a
larger screen.
2)
Check out the
“Q&A”
to review important ideas about
cloning
.
3)
Want to learn some more? Go to
“FYI”
to learn cool facts about
cloning
.
4)
How well do you understand
cloning

13. ? Take the
“Review Quiz”
to find out.
This is not an assessment – just practice! Your score is not
recorded.
5)
Close the window and return here to learn more!