Darwinism Alternatives

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Biology 1Carmela Española

Room 107, IB Main Building

M 10-12AM

TTh 10-12AM & 3-5PM

Darwinism and the alternative views on the origin of life

Evolution

Fact or Theory?

Evolution

• Process that changes populations of organisms over time

• Occurs through natural selection, gene flow and genetic drift

• Evidenced by:

– Microevolution: artificial selection, genetic variation maintained by natural selection

– Macroevolution: fossil record, comparative anatomy, comparative embryology, molecular biology

Addressing some misconceptions about evolution

Is not Is

• Adjustment to environment by

individuals

• Development of new traits by all

individuals

• Changes in % of population with a

gene/trait

• In response to wants or needs of

organisms

• In response to differences in survival and

reproduction

• Random • Dependent on mutations (which occurs at

random) and natural selection

(nonrandom chance of survival and

reproduction)

• Progressive

• Goal-oriented

• Adaptations depend on resources and

conditions

• Complexity is not necessarily favoured

• Organisms are not “higher” or “lower”

Addressing some misconceptions about mutation

Is not Is

• In response to needs of

organisms

• Random

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Darwinian Theory

Model for explaining the history and diversity of life

Darwin’s Theory

1. Organisms change

over time.

Organisms living

today are different

from those that

lived in the past.

Darwin’s Theory

2. All organisms branch from a

common ancestor.

Any pair of organisms has a

common ancestor

Similar organisms are similar

because they share traits with

their common ancestor

Darwin’s Theory

3. Change is gradual and slow,

taking place over a long time.

Supported by the fossil record

No naturalist has observed the

sudden appearance of a new

species

Two models of interpreting evolutionary patterns

1. Gradualist model

• Populations evolve differences gradually as they

become adapted to their local environments

• Presence of transition forms in the fossil record

Two models of interpreting evolutionary patterns

2. Punctuated equilibrium model

• Populations that undergo long periods of equilibrium where little

change takes place, punctuated by short periods of rapid change

• May account for the lack of transitional stages in fossil records

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Darwin’s Theory

4. The main mechanism of

evolutionary change

is natural selection.

Undirected or random

processes favour certain

heritable characters

Evolution and the origin of life

Early earth

• A recipe for life

Raw materials

+

Suitable environment

+

Energy sources

Early earth

• The possible composition of earth’s early atmosphere

– H2O vapor and compounds released from volcanic eruptions,

including N2 and its oxides, CO2, CH4, NH3, H2 and H2S

• As the earth cooled, water vapor condensed into oceans,

and most of the hydrogen escaped into space

• Many energy sources existed on the early earth

– Intense volcanic activity, lightning, and UV radiation

Early earth

S. Miller & H. Urey, 1953

• A. Oparin's and J. B. S. Haldane's

hypothesis: primitive Earth favoured

chemical reactions that synthesized

organic compounds from inorganic

precursors. “prebiotic soup”

• Geophysicists have now found that the

primitive Earth atmosphere contained

CO2, N2 and free O2

• J. P. Ferris and C. T. Chen: produced no

amino acids using correct compounds

Primordial Atmosphere Experiments

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The fossil record documents the

history of life

• The fossil record documents the main events in the

history of life

• The geologic record is defined by major transitions in

life on Earth

Mass extinctions destroy large numbers of species

• Extinction is the fate of all species and most lineages

• The history of life on Earth reflects a steady

background extinction rate with episodes of mass

extinction

• Over the last 600 million years, five mass extinctions

have occurred in which 50% or more of the Earth’s

species went extinct

EVOLUTION CONNECTIONAdaptive radiations have increased the diversity of life

• Adaptive radiation: a group of organisms forms new

species, whose adaptations allow them to fill new

habitats or roles in their communities

• A rebound in diversity follows mass extinctions as

survivors become adapted to vacant ecological niches

– Mammals underwent a dramatic adaptive radiation after the

extinction of nonavian dinosaurs 65 million years ago

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EVOLUTION CONNECTION

Adaptive radiations have increased the diversity

of live

• Adaptive radiations may follow the evolution of new adaptations, such as wings

– Radiations of land plants were associated with many novel features, including waxy coat, vascular tissue, seeds, and flowers

Different Reactions to Evolution

Young Earth Creationists

Day-Age Theorists

Progressive Creationists

Intelligent Design Proponents

Theistic Evolutionists

Material Evolutionists


1. Young Earth Creationists

• accept Genesis literally, including not just the special, separate creation of human beings and all other species, but the historicity of Noah’s Flood

• do not interpret the flat-earth and geocentric passages of the Bible literally, but they reject modern physics, chemistry, and geology concerning the age of the earth

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2. Day-Age Theorists

• each of the six days of creation is not a 24-h day but a long period of time, even thousands or millions of years

• found comfort in what they regard as a rough parallel between organic evolution and Genesis, in which plants appear before animals and human beings appear last


3. Progressive Creationists

• God created kinds of animals that were of a higher taxonomic level than species

• God created creatures containing at least as much genetic variation as a family (e.g. Felidae, Cercopithecidae) and considerable evolution within a kind then occurred


4. Intelligent Design Proponents

• certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection

• argue that an archaeologist who finds a statue made of stone in a field may justifiably conclude that the statue was designed, and reasonably seek to identify its designer


5. Theistic Evolutionists

• God created but relied more upon

the laws of nature to bring about His

purpose

• one species can give rise to another

• see God as intervening at critical

intervals during the history of life

especially in the origin of human

beings


6. Material Evolutionists

• go beyond science and propose that the laws of nature are not only sufficient to explain all of nature and evolution but that the supernatural does not exist

• philosophical materialism (naturalism) there is nothing in the universe beyond matter, energy, and their interactions

Where do you stand?

Young Earth Creationists

Day-Age Theorists

Progressive Creationists

Intelligent Design Proponents

Theistic Evolutionists

Material Evolutionists

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“

”

Faith is the great cop-out, the great

excuse to evade the need to think and

evaluate evidence.

Richard Dawkins

“To be termed scientific, a method of inquiry must be based on

empirical and measurable evidence subject to specific

principles of reasoning.”

Newton, 1999

System of the World

“

”

A scientific method is based on the

collection of data through observation and

experimentation…

Science Daily

“We see nothing of these slow changes in progress,

until the hand of time has marked the lapse of ages…”

Charles Darwin

“

”

We are condemned to live only for a few

decades and that’s too slow, too small a

time scale to see evolution going on.

Richard Dawkins

Evolution and society

• Science – addresses questions about natural world (empirical, material)

- does not address questions beyond the natural world

- these questions are left to religion and ethics

• Hypothesis – an idea to be tested

- can be supported but cannot be “proven”

- testable (falsifiable) hypothesis – material evidence could disagree

• Theory – hypothesis that’s been supported over and over again

- (e.g., germ theory, cell theory, theory of gravity, theory of evolution)

Evolution and society

• Science – addresses questions about natural world (empirical,

material)

- does not address questions beyond the natural world

- these questions are left to religion and ethics

“natural” ≠ good, right, just, moral

Does an evolutionary explanation for infidelity justify this behavior?

murder ?

discrimination ?

Evolution and religion

• What is the evolution versus creationism dispute about?

1) What is the origin of humans? Are we special?

If we’re “just” animals does this justify immorality?

Science does not deal with whether behaviours are moral or immoral, right or wrong.

2) Is God excluded?

If evolution can explain the origins of life, is there a role for God?

Science does not test hypotheses about the spiritual world.

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Where has centuries of scientific

achievement and knowledge

acquisition brought us?

“Any fetus is less human than an adult pig.”

Richard Dawkins700,000 +3,000,000 +5,500,000 +

Survival of the fittest?

Sources

• Slides were taken and modified from:

• Modified Bio12 slides

• Dr. Ma. Dolores Tongco

• Dr. Ian Kendrich Fontanilla

• Dr. Catherine Lagunzad

• http://www.bio.georgiasouthern.edu/

• Photos were from the internet.

Human EvolutionNext meeting

http://www.bio.georgiasouthern.edu/

Documents

Darwinism Alternatives