3. 3. Creationism and Creationism and evolutionismevolutionism

THE NATURAL SELECTIONTHE NATURAL SELECTION

What do you know about it?What do you know about it?

What will it happen to our tiny toe in What will it happen to our tiny toe in human feet next 500 years?human feet next 500 years?

Creationism and evolutionism are they Creationism and evolutionism are they compatible?compatible?

Which evidences do you know that Which evidences do you know that organisms have evolved along Earthorganisms have evolved along Earth’’s s history?history?

The origin of living thingsCreationism

We are in the 18th century and the dominant ideas in Europe are that living things have been created as we know them, they are immutable and don’t change along time

These ideas are based in Jewish and Christian beliefs taken from the Genesis, and according to it:

1. The world, and everything on it, was created in six days and would only be some 6 000 years old

2. God created species as they are now and they are immutable, they haven’t changed

CreationismCreationism

Two main creationist scientists were LINNEO and CUVIER

Famous Swedish botanist, he invented the natural system of classification and the binomial nomenclature

Karl Von Linneo (1707-1778)

…Catastrophist Theory, according to which along time on Earth great catastrophes had occurred that were followed by new creations

Father of Paleontology,due to his observations he realized that in ancient times faunae and florae different from present-days had existed, which led him to propose the...

Georges Cuvier(1769-1832)

Can we literally interpret what the Can we literally interpret what the Bible or other religious books say?Bible or other religious books say?

Is it necessary to opposite a religious Is it necessary to opposite a religious belief to present-day scientific belief to present-day scientific theories?theories?

Creationist ideas can be considered Creationist ideas can be considered as scientific theories?as scientific theories?

Three main questionsThree main questions::

Is intelligent design a scientific theoryIs intelligent design a scientific theory?? How could you explain the How could you explain the

appearance of so sophisticated appearance of so sophisticated mechanisms as a bacterial flagellum? mechanisms as a bacterial flagellum? The irreducible complexity?The irreducible complexity?

http://en.wikipedia.org/wiki/Evolution_of_the_eye

Eyes have been formed from simpler structures

Eyes have been formed from simpler structures

Is there a contradiction between Is there a contradiction between religious beliefs and science?religious beliefs and science?

Modern Theology accepts Modern Theology accepts cosmobioevolutioncosmobioevolution as an expression of as an expression of GodGod’’s creating powers creating power

It is not necessary for God to be It is not necessary for God to be directly present when all creatures directly present when all creatures appeared and he doesnappeared and he doesn’’t need acting in t need acting in specially specially ““difficultdifficult”” moments like the moments like the appearance of complex structures appearance of complex structures

Accepting GodAccepting God’’s part in creation is a s part in creation is a matter of faith, accepting scientific matter of faith, accepting scientific theories is nottheories is not

Harun Yahya and the Creation AtlasHarun Yahya and the Creation Atlas1. Growing influence of religion (Christianity,

Judaism, Islamism) in world’s vision, specially after S-11-2001. Return to religious orthodoxy and backward of secularism. Increasing of social rejection to evolutionism: 40 % of North-Americans consider it a completely wrong theory and accept creationism

2. The fact of evolution cannot be denied, although there is not a general agreement about the evolutionary mechanisms. There are no sorts of scientific creationism. A scientific hypothesis must be contrasted with facts and observations that support or reject it, but it cannot be sustained by the inability of another hypothesis to explain the facts

Why do they look so alike?Why do they look so alike?

EvolutionismEvolutionism

Evolution is a Evolution is a FACTFACT Theories to explain Theories to explain HOWHOW it has it has

occurred may be different and occurred may be different and theythey’’ve actually changedve actually changed

LAMARCKISMLAMARCKISM is a theory about is a theory about the the inheritance of acquired characters inheritance of acquired characters

DARWINISMDARWINISM is a theory about is a theory aboutthe natural selectionthe natural selection

The origin of living thingsEvolutionism

Creationism was objected by evolutionism, a new vision that started to spread since the 18th and mostly during the 19th century

For evolutionist scientists…

…living things have changed along time from others that had existed before,...…and produced new and different species, more and more complex

EVOLUTIONIST SCIENTISTS : LAMARCK, DARWIN & WALLACE

Jean Baptiste de Monet, Knight of Lamarck(1744-1829)

Professor at the Natural History Museum in Paris. In 1800 he gave a lecture where he exposed a coherent theory to explain the transformation of living things

He admitted the existence of the evolution of species and tried to give a rational explanation to it

LAMARCKISMLAMARCKISMis based on the following ideas:is based on the following ideas:

1.1. The environment The environment changeschanges2.2. Living things Living things need to adaptneed to adapt to these changes to these changes

3.3. In order to adapt, living things In order to adapt, living things use some organs use some organs better than othersbetter than others ((use and disuseuse and disuse))

4.4. Organs more frequently used Organs more frequently used developdevelop and and strengthen, and those less used strengthen, and those less used atrophy atrophy and and weakenweaken

5.5. Characters achievedCharacters achieved or lostor lost by living things along by living things along their life their life are transferred to their descendantsare transferred to their descendants ((inheritance of acquired charactersinheritance of acquired characters))

According to Lamarck, initially giraffes had a short neck but they should have stretched it as they needed to extend it to get food from the trees leaves and...

…their descendants would have inherited that feature

Charles Darwin (1809-1882)

In 1831 he enlisted on the survey ship HMS Beagle as a naturalist without a salary to start a scientific expedition around the world

In this voyage he made important geological and biological observations. In 1836, when he was back in England, he was devoted to gather his ideas regarding change in species

In 1859 he published his theory “On the Origin of Species by Means of Natural Selection”. This book opened a great debate and signified a major revolution in human thinking

He died on April 19, 1882 and was buried at Westminster Abbey

Darwin Online

Alfred Russell WallaceHe was born on January 8, 1823 at Usk, Monmoutshire, Wales. In 1848 he made an expedition to river Amazon with Henry Walter Bates, who was also a naturalist and, from 1854 till 1862, he commanded the research at the Malaysian isles. At that time he formulated his theory of the natural selection

In 1858 he told his ideas to Darwin, and an astonishing coincidence occurred, for Darwin himself had already a manuscript of his own theory of evolution

1823-1913

He died on November 7, 1913 at Broadstone, Dorset, England

The DARWIN-WALLACE theoryThe DARWIN-WALLACE theoryis based on the following ideasis based on the following ideas::

1.1. Most species reproduce in Most species reproduce in great amountsgreat amounts2.2. ResourcesResources (food, place, etc.) are (food, place, etc.) are limitedlimited3.3. Individuals of one species are not alike among them, there Individuals of one species are not alike among them, there

is always some is always some variability.variability. SomeSome variations variations are transferredare transferred to the descendantsto the descendants

4.4. The The struggle for survivalstruggle for survival: individuals must overcome : individuals must overcome conditions imposed by environment to surviveconditions imposed by environment to survive

5.5. The most favored surviveThe most favored survive (those that have the best (those that have the best adaptations to environmental conditions)adaptations to environmental conditions)

6.6. Natural selection Natural selection (reproduction and survival of the best (reproduction and survival of the best adapted) causes along generations the accumulation of the adapted) causes along generations the accumulation of the most favorable features according to the environment. So most favorable features according to the environment. So the the new species new species have originatedhave originated

7.7. Their Their descendants inherit the features from the ancestorsdescendants inherit the features from the ancestors

The case of giraffesThe case of giraffes

According to Darwin, in the populations of According to Darwin, in the populations of giraffes a certain variability existed. Some had giraffes a certain variability existed. Some had a longer neck than others. Individuals with the a longer neck than others. Individuals with the longest neck would be better adapted and longest neck would be better adapted and would have more descendants. Along time would have more descendants. Along time there would be more giraffes with a long neckthere would be more giraffes with a long neck

Why have Why have stickstick insectsinsects adopted adopted the shape of a stickthe shape of a stick??

Why are Why are nettle leavesnettle leaves stinging? stinging?

According to LamarckismAccording to Lamarckism::

Stick insects have adopted the shape of a stick to avoid being seen by predators

Nettle leaves are stinging to avoid being eaten by herbivores

According to Lamarckism:According to Lamarckism:Both the stick insect and the nettle

have their features due to the need of adaptation to survive

To avoid predators, stick insects’ ancestors adopted that shape, a new feature, and transferred it to their descendants

We can reason in a similar way for nettle leaves

According to DarwinismAccording to Darwinism:: Body shape is an inheritable feature.

Among the ancestors of stick insects there were some individuals with body shapes that allowed them to be unnoticed better than others to predators, what gave them more chance to survive and have an offspring

Generation after generation, natural selection favored the reproduction and survival of individuals that better seemed to a stick

We can reason in a similar way to explain the origin of nettle stinging hairs

Precursors of Neo-Darwinism

Limitations of Darwinism: Limitations of Darwinism: the need to modify the theory of evolutionthe need to modify the theory of evolution

When Darwin proposed his When Darwin proposed his Theory Theory on the Origin of Specieson the Origin of Species by means by means of of Natural Selection, Natural Selection, neither neither Laws Laws of Inheritanceof Inheritance nor nor mutations mutations were were yet knownyet known

Because of that, Darwinism had an Because of that, Darwinism had an important important contradictioncontradiction in itself, as in itself, as for the mechanism of evolution was for the mechanism of evolution was natural selection...natural selection...

...in this very process, along time, ...in this very process, along time, variability should disappearvariability should disappear, and , and consequently sooner or later consequently sooner or later evolution would stopevolution would stop

Neo-Darwinism: Neo-Darwinism: A Synthetic Theory of EvolutionA Synthetic Theory of Evolution

At the beginning of 20At the beginning of 20 thth century a new century a new theory is stated : theory is stated : Neo-Darwinism Neo-Darwinism oror the the Synthetic Theory of EvolutionSynthetic Theory of Evolution including including DarwinismDarwinism but also but also MendelMendel’’s Laws of s Laws of Inheritance Inheritance and the phenomenon of and the phenomenon of mutationsmutations

This is This is present-day mostly accepted present-day mostly accepted theory with new alternativestheory with new alternatives likelike symbiogenesissymbiogenesis (Margulis) and (Margulis) and punctuated equilibrium punctuated equilibrium (Gould)(Gould)

Neo-Darwinism revisitedNeo-Darwinism revisited

Lynn MargulisLynn Margulis (symbiogenesis)(symbiogenesis)

Stephen Jay GouldStephen Jay Gould (punctuated equilibrium(punctuated equilibrium))

The origin of living things: Neo-Darwinism

This theory is based on the following ideas:

1) Living things undergo some variations due to random mutations, what produces variability among individuals of the same species

2) Natural selection acts upon them. The best adapted individuals survive, have a larger offspring and their characters spread among population. The worst adapted have less descendants and their genes tend to disappear

3) Those progressive changes accumulate along time and produce changes in populations what generates new varieties, breeds and species

According to Neo-Darwinism, giraffes should have evolved as follows:

The origin of living things: Neo-Darwinism

Among the giraffes’ antecessors, that were animals with a short neck, mutations produced some individuals with a longer neck

http://evolutionibus.eresmas.net/neodarwinismo.html

…longer and a shorter neck. Natural selection acts upon variability

Along time all giraffes will have a longer neck. Evolution doesn’t stop because mutations ensure that there will always be some individuals with a...

If this character represents an advantage, the individuals will reproduce in a greater amount and...

…the number of the long necked will increase

The origin of living things: Neo-Darwinism

EVOLUTION THEORIES

EVOLUTION EVIDENCES

Evolution is nowadays a very well based and settled theory despite the existence of some fundamentalist tendencies that, against all evidences, still defend creationism absurdly and irrationally

Evidences on which evolution is based are:

• Paleontological evidences• Morphological evidences• Biogeographic evidences• Embryological evidences• Biochemical evidences

EVOLUTION EVIDENCES

PALEONTOLOGICAL EVIDENCES: INTERMEDIATE FORMS

Some fossils present intermediate features between groups of living things, what shows us from which organisms could certain groups of living things have evolved

For example, the Archaeopteryx, ancestor of birds, presents intermediate features between birds and reptiles (feathers, reptile teeth, claws at their wings, ...)

The study of fossils allows us to reconstruct how the evolutionary process has happened for a certain organism, and so we are able to know which changes has experienced one particular species since its ancestor until its modern aspect

PALEONTOLOGICAL EVIDENCES: PHYLOGENETIC SERIES

At the picture we can see the phylogenetic series for the leg of equines: a) Hyracotherium (eocene, 50 m.y.). b) Mesohippus (oligocene, 30 m.y.). c) Merychippus (miocene, 15 m.y.) and d) Equus (modern horse)

Phylogenetic series for horse and its family, equines , in general (horses, zebras and donkeys)

PALEONTOLOGICAL EVIDENCES: PHYLOGENETIC SERIES

PALEONTOLOGICAL EVIDENCES:PHYLOGENETIC SERIES FOR HUMAN SPECIES

PALEONTOLOGICAL EVIDENCES: LIVING FOSSILS

These are organisms that have hardly evolved and have remained almost changeless along millions of years. Examples:

Araucaria Coelacanths

MORPHOLOGICAL AND ANATOMICAL EVIDENCES

Based on a comparative study of morphology and anatomy of living things

We shall distinguish here between homologous and analogous organs

Analogous are organs with a different origin that have a similar aspect because they have a similar purpose. For example: insect’s and bird’s wings. Analogy shows a convergent evolution by adaptation of different structures to the same environment or purpose: flying, in the given example

Homologous are organs with the same origin and similar structures that are different because of their different functions. For example: a bat’s wing, a horse’s leg, a whale’s fin or the prehensile extremity of a primate. Homology is explained by a process of divergent evolution or adaptation of the same organ to different purposes and environments: flying, running, swimming or climbing

MORPHOLOGICAL AND ANATOMICAL EVIDENCES

Example of HOMOLOGY

We can see an example of homologous organs in anterior extremities of vertebrates: a) human’s arm, b) feline’s leg, c) whale’s fin, d) bat’s wing

Homology shows an evolutionary relationship, a common origin where differences are due to a process of divergent evolution or adaptive radiation. Organs have a very different function but possess the same structures, the same bones

Organs are very different in their function but they have the same structures, the same bones

MORPHOLOGICAL AND ANATOMICAL EVIDENCES

An example of ANALOGY: sharks, swordfishes, ichthyosaurs (fossil reptiles) and dolphins have a similar shape

This fact in not the result of a common origin neither a relationship, it can only be explained by an adaptation process...

MORPHOLOGICAL AND ANATOMICAL EVIDENCES

…to the same aquatic environment, made by very different living things (a cartilaginous fish, a bone fish, a reptile and a mammal)

It is then a case of analogy that shows a convergent evolution or adaptive convergence

MORPHOLOGICAL AND ANATOMICAL EVIDENCES

Circulatory Apparatus in Vertebrates

FISHES AMPHIBIANS REPTILES BIRDS AND MAMMALS

MORPHOLOGICAL AND ANATOMICAL EVIDENCESVESTIGIAL ORGANS

They are atrophied organs, without any function at present, that reveal the existence of ancestors for whom these organs were necessary

We find a good example at the rests of the whales’ posterior extremities, what reveals...

...their past as quadrupeds

BIOGEOGRAPHIC EVIDENCES OF EVOLUTION

One of the most demonstrative proves or evidences of evolution is the geographic distribution of a series of large birds

http://www.damisela.com/zoo/ave/ratities/index.htm

The existence of African ostrich, South-American Greater Rhea and Australian cassowary and emu can only be explained by means of the theories of evolution and plate tectonics

BIOGEOGRAPHIC EVIDENCES OF EVOLUTION

Hypothetical continent that, at the end of the primary period, gathered in only one bloc all the lands that constitute at present Australia, S and SW Asia, Madagascar, Africa, South-America (northern part) and Antarctica

At the north, a different continent was formed, named as Laurasia, including North-America, Europe and north of Asia

GONDWANA

BIOGEOGRAPHIC EVIDENCES OF EVOLUTION

1. Some 100 million years ago, a common ancestor to these birds developed and spread out all over Gondwana. That is the reason why there are not running birds in Laurasia, the northern continent

2. When Gondwana split the different populations of birds remained isolated and evolved separately what produced different species

Explanation of the geographic distribution of giant running birds

EMBRIOLOGICAL EVIDENCES OF EVOLUTION

They are based in the study of embryonic development of living things. Those species with a greater evolutionary relationship show more similarities in the processes of embryonic development. Similarities in the first stages of embryonic development in vertebrates show the existence of a common ancestor, as we can see in this picture:

BIOCHEMICAL EVIDENCES OF EVOLUTION

One of the most important evidences is based in a molecular level similarity between proteins or DNA from different organisms. This similarity is the more relevant when...

…the more the evolutionary relationship is between them

Compared species Differences in DNA (%)

Man-Gorilla 1.4

Man-Chimpanzee 1.2

Gorilla-Chimpanzee 1.2

Man-Orang-utan 2.4

Gorilla-Orang-utan 2.4

Chimpanzee-Orang-utan

1.8

Differences in DNA between pongids and human species

Similarities and differences also appear at the protein level. The table shows the percentage of agglutination produced when we mix in a test tube bloody plasma from different animals and antibodies against proteins from human bloody serum, taken from rabbits that have been injected human serum. We conclude that...

Species % Agglutination

Man 100

Chimpanzee 85

Gorilla 54

Orang-utan 42

Baboon 29

Ox 10

Deer 7

Horse 2

Marsupial 0

…the higher the percentage of agglutination

…the higher the similarity between animal and human proteins...

...what measures the degree of evolutionary relationship

BIOCHEMICAL EVIDENCES OF EVOLUTION

HOW DO NEW SPECIES APPEAR?

Varieties appearance: the example of Biston betularia

Biston betularia is a butterfly that feeds a lot of bird species. Until 1850 in England there was only the clear variety, a color similar to that of the bark of trees on which it used to stop

Since 1850 on, with the industrial development and the rapid growth of factories, the dark variety started to be the most plentiful in industrial zones, while in agricultural zones...

…the most plentiful is still the clearer variety!!!

HOW DO NEW SPECIES APPEAR?

Explanation

If trees are not contaminated, their bark has a clear tonality. In this case the best adapted variety is the clear variety, for it is hardly seen by birds. The few dark individuals originated by mutation...

...are easily detected by birds that eat them and...

…consequently, leave NO offspring

HOW DO NEW SPECIES APPEAR?

Contamination lets lichens die and the bark of trees becomes darker. Thus dark individuals appeared by mutation are more difficult to see, so they are NOT detected. Clear individuals, worse adapted, undergo the effects of depredation. Under theses conditions...

...there will be along time…

…MORE AND MORE....

…dark individuals

HOW DO BREEDS APPEAR?

If different populations of individuals of the same species undergo variations that make them different, because of remoteness or other reasons, there will appear...

...breeds of the same species. Individuals from different breeds...

…CAN REPRODUCE BETWEEN THEM

CONCEPT OF SPECIES

A whole of individuals that belong to natural populations able to reproduce between them and give a fertile offspring

Sometimes it may happen that individuals of different species may reproduce between them (a horse and a donkey) but their young(mule) are sterile

HOW NEW SPECIES ARE PRODUCED?

The appearance of new species requires the existence of changes in genetic features of the population and that origins a different individuals’ population but, besides that,

…an isolation must occur to make impossible that new features...

…be transmitted to individuals from other populations

But, how can such an isolation happen?

The main forms of isolation are:

a) Geographic : populations become isolated by geographic accidents like seas, rivers, deserts,...

b) Reproductive : although individuals remain in the same territory, genetic variations produced by mutations can obstruct to a group of individuals from the original population to reproduce with the rest and produce a reproductive isolation that will origin in time a new species

APPEARANCE OF SPECIES BY GEOGRAPHIC ISOLATION

Distribution of different breeds of the same species in African continent. In zones where there are some populations that have been isolated speciation can happen

Isolated zones where speciation can happen

Non isolated zones that can produce different varieties or breeds but not different species, because there is a genetic relationship

SCHEME OF SPECIATION BY ISOLATION

1) An original population (a) disperses along a wide territory

2) Thus, different populations are originated on which genetic differences produced by mutations can make new varieties or breeds to appear (a1, a2, a3, a4)

3) One of the breeds (a3) may become isolated by a geographic barrier (for example) and...

...along time genetic differences can produce a reproductive isolation and the appearance of a brand-new species (b1)

Is evolution a matter of faith?Is evolution a matter of faith?1. It is not a matter of faith. Evolution

is a fact based in numerous proofs2. At the final part of the unit we have

given a lot of proofs of different kinds that can only be explained by evolution as a fact: paleontological, morphological and anatomical, biogeographic, embryological and biochemical proofs or, even better, scientific evidences

To learn moreTo learn more http://evolution.berkeley.edu/http://evolution.berkeley.edu/ http://bioinformatica.uab.es/divulgacio/evol.htmlhttp://bioinformatica.uab.es/divulgacio/evol.html http://www.aboutdarwin.com/http://www.aboutdarwin.com/ SAMPEDRO, Javier. SAMPEDRO, Javier. Deconstruyendo a Darwin: los Deconstruyendo a Darwin: los

enigmas de la evolución a la luz de la nueva enigmas de la evolución a la luz de la nueva genética. genética. Barcelona: Crítica, 2007Barcelona: Crítica, 2007

AYALA, Francisco. AYALA, Francisco. Darwin y el diseño inteligente: Darwin y el diseño inteligente: creacionismo, cristianismo y evolución. creacionismo, cristianismo y evolución. Madrid: Madrid: Alianza Editorial, 2007Alianza Editorial, 2007

DAWKINS, Richard. DAWKINS, Richard. El espejismo de Dios. El espejismo de Dios. Madrid: Madrid: Espasa Calpe, 2007Espasa Calpe, 2007

SCHMITZ-MOORMANN, Karl. SCHMITZ-MOORMANN, Karl. Teología de la Teología de la creación de un mundo en evolución. creación de un mundo en evolución. Estella: Estella: Editorial Verbo Divino, 2005Editorial Verbo Divino, 2005