Download Honors Biology Module 9 Evolution

Honors Biology
Module 9: Evolution
January 7, 2016
HAPPY NEW YEAR 2016
Class Challenge: GO TEAM !!!
Charles R. Darwin
In 1859, Darwin published a book entitled,
On the origin of Species by Means of
Natural Selection, or the Preservation
of Favoured Races in the Struggle for
Life.
This long book title is commonly referred to
as, The Origin of Species.
This work sent shockwaves through the scientific
community because at the time, science was
inseparably linked to God.
Most scientists were formally trained in the Bible
and many were clergy.
So when Darwin’s work was published, they could
not imagine a scientist who didn’t refer to God as
a natural part of his scientific inquiries.
To other scientists of the day, it was just what they
had wanted. They did not believe in God, and
finally an idea had come along that told them
how we came to be without referring to anything
supernatural.
The wisest man who ever lived, King Solomon
said: There is nothing new under the sun.
Today, Darwin’s theory of Evolution has
become the standard explanation for the
origin of life on this planet.
It is not because of the scientific evidence,
because Darwin’s theory never left the
stage of hypothesis.
Why had Evolution been so widely
accepted by people of faith?
1. There are those people who assume that
it must be true, since the majority of
scientists today believe it is. As a result
Christians try to make the scriptures of
their faith (Genesis 1-2) consistent with
evolution.
Day/ age theory
2. Then there are those who will not even
consider the theory, because it runs counter to
what they believe Scripture teaches.
3. Then there are those who fall between those
two ends of the spectrum, attempting to either
integrate the idea of evolution into their faith on
one level or another, or rejecting part or all of
the theory because it is considered
incompatible with their faith.
Who is Right?
Let’s examine the theory and see where it
stands in the light of current scientific
knowledge.
Darwin studied medicine at the University of
Edinburgh but soon gave that up. He
transferred to Christ’s College in
Cambridge, England to study theology.
Contrary to what many believe, he seemed to be a
committed Christian at this point in his life. He
received a BA is theology, Euclid and the
classics.
While at Cambridge, he developed a keen interest
in geology. He accompanied a Cambridge
professor, Adam Sedgewick on a geology field
trip in the summer of 1831. He was offered a
position as a Naturalist on the HMS Beagle.
This ship was to circumnavigate the globe.
Darwin’s Voyage on the HMS
Beagle
Before the voyage…
Darwin read Thomas Malthus book,
An Essay on the Principles of Population.
Malthus said that all individuals within a
population struggle against other
individuals to obtain what is necessary
(food, shelter, a mate, etc.) in order to
survive and reproduce.
While at sea….
Darwin read some works of controversial
geologist , Sir Charles Lyell. He was one
of the first scientists who rejected the
history of the world as told in the Old
Testament and tried to show that the same
processes we see at work today could,
given eons and eons of time, produce all
of the geological features in the world.
Lyell’s idea is simply, “The present is the
key to the past.”
Darwin voyaged for 5 years….
And during that time he made many
observations. He collected samples and
made observations of the species native to
whatever island or land mass he was on.
These observations, combined with Malthus
and Lyell, led Darwin to formulate his theory,
which he called, “natural selection.”
His theory was completely formulated by the time
he left the HMS Beagle, he did not publish his
book for another 23 years.
Part of the delay was due to Darwin trying to
perfect his work, but most of it was due to his
wife, who recognized the devastating effect that
his work could have on the church.
He eventually published, The Origin of Species in
1859.
Interesting Point….
It is important to note that Darwin was a careful,
meticulous scientist. He was not the anti-religion
crusader that many have made him out to be. If
you actually read his work, you will find that it is
quite evenhanded.
In his book, Darwin devoted more space to the
reasons a scientist might not want to accept his
main hypothesis than he did to the discussion of
why a scientist should accept it.
Darwin’s faith eroded while on the HMS
Beagle and the years after by comparing
two statements he made.
During the earliest part of the voyage, he
wrote in his diary that he often bore the
brunt of a good deal of laughter :
“….from several of the officers for quoting
the Bible as final authority on some moral
point.”
Only a few years after his voyage, he stated that:
“…..the Old Testament from its manifest false
history of the world, with the Tower of Bable, the
rainbow as a sign, etc., etc., and from it
attributing to God the feelings of a revengeful
tyrant, was no more to be trusted than the
sacred books of the Hindoos [sic], or the beliefs
of any barbarian.”
Darwin died in 1882 as a celebrated
naturalist whose views were said to usher
in a new age of science.
He was buried in Westminster Abby along
with Sir Isaac Newton and Lord William
Thomson Kelvin.
Important to Note
1. Darwin never recanted his theories on his
deathbed as some believe.
2. Although Darwin’s theory has had devastating
effects on the faith of many people, Darwin
was not an anti-religion crusader like many
evolutionists are today.
Darwin was a careful, dedicated scientist who
started his career speaking like a Biblebelieving Christian. He was merely
communicating what he thought were the
obvious conclusions of his scientific studies.
3. Even careful use of the scientific method can
result in the wrong conclusion.
Despite the fact that Darwin did everything right in
terms of the science that he did, we can show
that although a portion of his theory is valid,
the major conclusion is not.
Proper use of the scientific method does not
guarantee a correct answer.
Examining Darwin’s life can show you how
horrible the results are when you put your
faith in science.
As we discussed, science is limited and is
constantly changing. What we thought
were scientific laws less than a century
ago are now known to be wrong.
The Galapagos Archipelago Islands
The HMS Beagle
Sailed to the Galapagos Archipelago, which
are 13 islands that were formed by
volcanos 600 miles west of Ecuador,
South America.
Darwin studied a wide variety of plants and
animals, he concentrated on finches that
lived there.
Darwin’s Finches
Figure 9.1
There are many different species of finches living
in the Galapagos. There are several common
characteristics, but there are specific differences
between each species that were of great interest
to Darwin.
Notice that Certhidea has a small slender beak
while Geospiza has a large, stouter beak, and G
Magnirostris has the largest, stoutest beak of the
three.
Why do these finches have such different beaks?
Let’s look at what they eat….
C. Olivacea eats tiny insects.
G. Difficilis eats eggs that it steals from nests, but
it does not use its beak to break them. Instead,
it grabs onto something with its beak and then
kicks the eggs into a rock.
G. Magnirostris eats hard seeds that it much
crack with its beak.
Each finch seems to have just the right beak for its
food source: a small, slender beak for the finch
that eats soft insects; a larger, sturdier beak for
the one that uses it as an anchor; and the
largest, sturdiest beak for the one that uses it to
crack seeds.
Differences like these fascinated
Darwin….
Scientists of Darwin’s day would have looked
at each of these species and assumed that
God had designed each one individually
and gave each one exactly the beak that it
needed to eat the food it was suppose to
eat.
Personally, that is what I believe.
Darwin, said that the other than the beak
and a few other differences (size and
plumage color), these finches were all
remarkably similar.
Since they were all so similar, he imagined
that they all came from a common
ancestor long ago.
As the feeding needs of the finches
changed, this common ancestor began to
give rise to many different species of finch,
each with its own unique beak.
How did Darwin propose that this
could happen?
Look at any species when it reproduces.
When two people have a baby, the baby has
many characteristics in common with his
parents. (remember the Punnet Chart)
The baby usually has some characteristics
that do not seem to come from either
parent. (Parent’s alleles are carriers)
Some tall professional basketball players
have short parents.
So…
Even though offspring do tend to resemble
their parents, they also have a few
characteristics that are quite different from
the corresponding characteristics in their
parents.
Darwin made an hypothesis:
It is those differences that Darwin thought
could be responsible for all of the finches
in the Galapagos.
Suppose long ago….
There was only one species of finch living on the
islands. If food supplies were to grow scarce
(another hypothesis), the finches that made up the
population of this species would complete with one
another for the dwindling food supplies, just as
Malthus predicted.
When this competition began occurring, any finch that
had an advantage would be more likely to win the
competition than one who did not.
(Thomas Malthus book: An Essay on the Principles
of Population. )
Suppose a finch was born that had a beak
which was stronger than the typical finch.
That finch might be able to find a new
source of food (hard nuts that other
finches couldn’t break open).
With this new source of food, this strongbeaked finch would most likely win the
competition for survival.
As it reproduced it would be most likely pass on
this new, strong beak to at least some of its
offspring. Over many generations, each time
one of these finches was born with an even
stronger beak, it would be more likely to survive,
because it could continue to find more food than
the finches with which it was competing.
This competition combined with the natural
differences that arise between parent and
offspring, could over many generations produce
a finch whose beak was short and stout like G
Magnirostris, even if the original species of finch
had a small, slender beak, like that of C.
olivacea.
Testing the Hypothesis
• After leaving the HMS Beagle, Darwin began
experimenting with pigeons. He raised and bred
them trying to see if natural selection could
result in a new species of pigeon.
• He talked with other animal breeders (dogs,
horses and pigeons). He found much
evidence that confirmed at least part of his
hypothesis.
He noted several cases of breeders who
over several generations succeeded in
producing pigeons that were so different
from the species with which the breeders
stared that they could reasonably be
classified as a new species of pigeon.
The same seemed to be the case with dogs
and horses as well.
Darwin also compared domesticated
versions of many animals with their wild
counterparts. Wild dogs looked and
behaved differently from domesticated
dogs.
Many breeds of domesticated dogs cannot
reproduce with wild dogs.
These domesticated dogs would be considered a wholly
different species from any species of wild dog.
Despite these differences, domestic dogs were many
generations ago simply wild dogs that men began to
train and domesticate. Over generations, dog breeders
would selectively mate those dogs that had what the
breeder considered the best traits for domestication.
The “wilder” dogs were not allowed to reproduce, and the
tamer dogs were. This “manmade” selection, mimicked
natural selection, allowing the small variations that
occurred during reproduction to “pile up” leading to a
new species of dog: the domesticated dog.
Darwin was able to do two things:
1. He established as a valid scientific theory
the idea that the natural variations which
occur during reproduction could, when
guided by natural (or manmade) selection,
take one species and pile up so many
changes that the result could be
something reasonably classified as
another species. He showed that his
explanation for the many species of
finches in the Galapagos was scientifically
viable.
2. Darwin was able to destroy forever an idea
that had been established for generations
before him:
The immutability of species
This is the idea that each individual species on the
planet was specially created by God and could
never fundamentally change.
Scientists of Darwin’s day believed that
every creature was created during the time
of creation and has existed, essentially the
same, ever since that time.
Darwin masterfully showed that this just
wasn’t true. He showed that all of these
breeds of dog come from some original
dog ancestor, and the natural variations
that occurred in reproduction, guided by
natural (or manmade) selection, resulted
in the many different breeds of dog that
exist to this day.
Let’s be Specific….
Although Darwin had remarkable success in
testing his hypothesis, what Darwin
showed to be true was only a small part of
his hypothesis of evolution.
The idea that one ancestral finch could over
generations give rise to many different
species of finch was revolutionary, but it
was not where Darwin’s ideas stopped.
Once he had destroyed the idea of
Immutability of the species, he wanted to go
much further.
He wanted to show that the same process, over
millions (perhaps billions) of years, could,
eventually, cause the ancestral finch to give rise
to an eagle. (his hypotheses was that the earth
was old, not young)
This is where Darwin ran into all sorts of trouble
when comparing his hypothesis to the data.
Darwin found some evidence…
for this idea, but it was inconclusive at best.
There was so much data contradicting this
part of his hypothesis, that he spent the
majority of his book discussing the
problems with his hypothesis.
Darwin found….
Ample evidence that starting with a basic life
form (a finch, for example) many other
specialized species of this life form (many
species of finch) can arise as a result of
variation guided by natural (or manmade)
selection.
However, when it came to showing that a
basic life form (once again, a finch) could
evolve into a completely different life form
(like an eagle) by natural selection, there
was little to no evidence supporting his
hypothesis and plenty of evidence against
it.
This has led scientists to divide
Darwin’s Theory of Evolution
Into two parts:
1. Microevolution: the theory that natural selection
can, over time, take an organism and transform it
into a more specialized species of that organism.
2. Macroevolution: The hypothesis that processes
similar to those at work in microevolution can, over
eons of time, transform an organism into a
completely different kind of organism.
The difference between macroevolution and
microevolution cannot be overemphasized.
There is so much evidence to support the idea
of microevolution that it is a well-documented
scientific theory.
Macroevolution
There is so little evidence for macroevolution
and so much evidence against it that it is
to this day an unconfirmed hypothesis.
Why is Macroevolution the prevailing
thought is science today?
Darwin said that since microevolution is so clearly
apparent from a scientific point of view, then
macroevolution should also be rather obvious.
If finches can change a little over a small amount of time,
shouldn’t they be able to change a lot over a long period
of time?
This assumes that the amount of change a given species
can experience is essentially limitless, it will just take a
little longer for microevolution to slowly lead to
macroevolution.
Is this hypothesis or theory??
In Darwin’s day this sounded
reasonable…
But they did not know what we know today
about genetics.
Remember from Module 8 that the genetic
code is responsible for determining the
range of characteristics that a species has.
What they did not know….
Is that the natural variation we see in reproduction
today is simply the result of different alleles
being expressed in different individuals.
Since we know that the number of alleles in the
genetic code of any species is limited, we also
know that the natural variation which occurs as a
of reproduction is limited as well.
The variation that a species can experience
is not unlimited. It is limited by the
number and type of alleles in the species’
genetic code.
Today we know that macroevolution cannot
occur the same way that microevolution
occurs.
Microevolution
When God created the animals and plants, he
built into their genetic code a great amount
of variability.
These plants and animals began reproducing,
this variability began manifesting itself.
Macroevolution
Assumes that a given life form has an unlimited
ability to change. This means that some
process must exist to add information to the
creature’s genetic code.
There are only a certain number of genes and
alleles of those genes. Therefore there is only a
certain number of possible variations in
genotype and therefore a limited number of
possible phenotypes.
As Biology Students and
Scientists…
In order to get an unlimited amount of
change, a creature must somehow find a
way to add genes and alleles to its genetic
code.
This is something altogether different from
microevolution. There is little data
supporting such a hypothesis and quite
a lot of data contradicting it.
Geological Column and Transitional
Fossils
Geologist Lyell influenced Darwin as he interpreted
the geological column.
Lyell said that the strata shown in Figure 9.2 was
laid down over vast eons of time. So the strata
that geologists see was formed when sediments
accumulated slowly over time.
Again, Lyell’s hypothesis that Darwin adopted.
Young earth vs. old earth
As Lyell observed, and it results in layers of sediment.
Lyell continued and said that various chemical and
environmental factors would take a given layer of
sediment and harden it into rock.
Various chemical and environmental factors would
take a given layer of sediment and harden it into
rock. This would result in a single layer of
sedimentary rock.
As time went on, another layer of
sediment would slowly accumulate on
top of this this layer of rock forming
another layer of sedimentary rock on
top of the previous layer.
Figure 9.2 shows the geological
Column. Notice as you go deeper,
the fossils seem to get more “simple.”
Think back to our earlier modules, we have
learned that there is no such thing as
“simple” life form (ie: bacteria), but we are
talking about evidence for Darwin’s
hypothesis of macroevolution.
Darwin and others did not have the benefit
of microscopic analysis and detailed
explanations of how organisms work.
They did not really know that there is no
such thing as a simple life form. Instead,
they saw that the strata which were near
the surface of the earth contained fossils
of animals like horses, lions, and humans,
while the deeper strata gave way to fossils
of life forms like reptiles and small
mammals. Even deeper, these fossils
disappear and only fossils such as fish,
squids, and trilobites remain.
Hummm…?
So….
This progression according to Darwin went
from fossils that were “complex” organisms
like humans to “simple” organisms like
squids.
In Figure 9.2
First, this is a common representation of a
geological column, but it is not what it
actually looks like.
95% of all fossils that we recover are those
of clams and similar organisms. There are
fossilized clams in every region of earth in
nearly every layer of rock.
Think about it…..
So what we are showing in this representation is
only about 5% of the fossil record.
The geological column is usually discussed in
reference to macroevolution, the clams are
ignored.
So any conclusions you make based on the
geological column are based on a tiny
minority of the available data.
Second, it is very important to realize that
the geological column is an idealized
representation of the sedimentary rock
and fossils that we see on the earth.
There is really no place on the planet where
you can dig and find every layer of the
geological column as well as the fossils in
those layers.
Transitional Fossils
If Macroevolution did occur , the one huge problem
is that there are no transitional fossils.
Paleontologists should be able to find series of
fossils that demonstrate how one species slowly
evolved into another.
We should be seeing loads of them in the fossil
column and we have not found one.
If wild dogs, did eventually give rise to
horses, then there should be fossils of
animals that are somewhere between a
dog and a horse.
Darwin called these live forms (which he
assumed must have existed)
intermediate varieties.
Today they are know as…..
Intermediate links or transitional forms.
There are only a few examples of fossils that
might be interpreted to be intermediate
links, and even for those fossils, their
status as intermediate links are
questionable.
Have you heard of ….
The missing link ?
That is what we are referring to when
scientists say,
“Intermediate links or transitional forms”
Darwin wrote….
“Geological research, though it has added
numerous species to existing and extinct
genera, and has made the intervals between
some few groups less wide than they otherwise
would have been, yet has done scarcely
anything in breaking the distinction between
species, by connecting them together by
numerous, fine, intermediate varieties; and this
not having been affected, is probably the
gravest and most obvious of all the many
objections which can be raised against my
views.” (Charles Darwin, The Origin of Species,
6th ed, [New York, NY: Collier Books, 1962],
462)
Dr. David Raup, curator of the Chicago
Field Museum of Natural History
“Well, we are now about 120 years after Darwin,
and knowledge of the fossil record has been
greatly expanded… ironically, we have even
fewer examples of evolutionary transition than
we had in Darwin’s time. By this I mean that
some of the classic cases of Darwinian change
in the fossil record, such as the evolution of the
horse in North America, have had to be
disgarded or modified as the result of more
detailed information.”
(David Raup, Field Museum of Natural History
Bulletin, 50: 25, 1979 – emphasis added)
So the missing links are still
missing……?
“…according to Darwin…the fossil record should
be rife with examples of transitional forms
leading from the less to more evolved…Instead
gaps in the fossil record with so-called missing
links, most paleontologists found themselves
facing a situation in which there were only gaps
in the fossil record, with no evidence of
transformational intermediates between
documented fossil species.
(Jewffrey H,. Schwartz, Sudden Orgins, [New York,
NY: John Wiley & Sons, 1999], 89
Jeffrey Schwartz, Macroevolutionist
“Darwin may have argued that new species
emerge through slow, gradual
accumulation of time mutations, but the
fossil record reveals a very different
scenario – the sudden emergence of
whole new species, with no apparent
immediate ancestors.”
How do Evolutionists Explain this?
1. Punctuated Equilibrium assumes that these
transitional forms that link one species to
another do not live for very long. As a result,
there is not much chance of them fossilizing.
(Survival of the fittest ?)
2. There are some fossils that can be pointed to
as possible transitional forms. Their status as
transitional forms are highly questionable.
I subscribe to the following
explanation for creation ….
Examination of Local fossils
Gary Parker - From Evolution to
Creation (1 of 4)
http://youtu.be/Gu5G8TEA6F8
Gary Parker - From Evolution to Creation (2
of 4)
http://youtu.be/PFisXokqn0A
Gary Parker - From Evolution to
Creation (3 of 4)
http://youtu.be/wp_AWR6xAT8
Gary Parker - From Evolution to
Creation (4 of 4)
http://youtu.be/V70NZL45cYs
What Made a Biology Professor
Evolve into a Creationist?
• http://youtu.be/tBEPiCTAIMU
Homework
Read Module 9 page 276 – 294
OYO questions: 9.1 – 9.7
Study Guide a-e questions 2- 10
Class challenge: Creative Hat Day
Class Quiz: Explain the
difference between
Microevolution and
Macroevolution