Honors Biology

Module 9: Evolution

January 9, 2014

HAPPY NEW YEAR 2014

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 who assume that it must be true, since the majority of scientists today believe it is. As a result they 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.

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.

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 antireligion crusader like many evolutionists are today.

Darwin was a careful, dedicated scientist who started his career speaking like a Bible-believing Christian. He was merely communicating what he thought were the obvious conclusions of science.

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 FinchesFigure 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 look 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.

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.

The baby usually has some characteristics that do not seem to come from either parent.

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.

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, 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.

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 strong-beaked 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.

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.

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.

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.

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.

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, 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 who 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.

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.

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 ?

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.

2. There are some fossils that can be pointed to as possible transitional forms. Their status as transitional forms are highly questionable.

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: goofiest eyewear

Class Quiz: