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“It suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn't feel like a giant. I felt very, very small.” – Neil Armstrong (1930-2012)

Fresh Reads from the Science 'o sphere!

Tuesday, July 17, 2007

One Word - Many Evolutions

Evolution just means "change".

Just like amigos para siempre means "you'll always be my friend".

And amics per sempre means a love that cannot end.


As I was saying, evolution is a general term used to describe any process of change or formation.

Opponents of science, especially creationists, are so accustomed to their monolithic belief systems that they tend to lump all scientific fields together into a single, monolithic bloc.

Good for the ol' one-to-one dick fight.

Creation vs Evolution!

Faith vs Human Reason!

Great for selling tickets.

In reality, scientists construct our current understanding of the Universe piece by piece, from different disciplines, using different approaches and techniques.

It's not a house of cards, where finding a single weakness can bring the whole shebang down.

Each field has its own stacks of data to back up their main theory, and each one stands on its own merit.

In order to refute all evolutionary theories in science, no amount of rhetoric or politicking is enough. You'll need tonnes of evidence and brand new theories that have better explanatory power, clearer mechanisms and more superior predictive capabilities than all existing theories.

This means "many painful years of work".

We should be cautious of theories that cannot (or need not) be tested experimentally. Or "scientists" who don't do any original research.

So, when creationists attack evolution as if it is a monolithic theory, they are actually up against all these "evolutions" (and one non-evolution):

1. Evolution of the Universe

Scientific field: Physics
Techniques used: astronomical observations, cosmic background radiation, abundance of primordial elements...
Current theory: Big Bang

Doesn't it sound crazy? Our entire Universe just popped into existence billion of years ago from a singularity. Most physicists in the 1930s thought so too.

They were more comfortable with the idea of an eternal Universe until George Lemaitre snapped them out of their worldviews and expanded their minds.

Did I forget to mention the gobs of evidence needed to convince his colleagues? To rock the state of steadiness in his scientific rivals?

More than 70 years later, few scientists will bat an eyelid to the suggestion that our Universe is almost 14 billion years old. In addition, this theory fits quite well with many belief systems.

Unfortunately, there are people who will pick and choose what they believe from any idea.

Some people accept that the Universe has a beginning, but insist that the Universe is only 6000 years old.

Why, that's like ordering an egg bacon spam and sausage without the spam.

Lovely spam!

2. Evolution of the Solar System

Scientific field: Physics
Techniques used: astronomical observations, planetary/meteoroid chemical composition...
Current theory:
Solar Nebula

When you give yourself some spin - the entire Universe seems to revolve around you.

Which is why once the Earth was unseated as the centre of the Universe, the Sun immediately filled that role.

Although we now know that our Sun is just an average star in a remote corner of our galaxy (if spirals can have corners), its importance should not be underestimated.

Without the Sun, the planets wouldn't exist.

They wouldn't be orbiting the Sun in nearly circular, prograde (counter-clockwise from north pole) orbits.

There wouldn't be any atoms to make our bodies.

There wouldn't be any energy to keep us warm.

There wouldn't be any light for plants to make our food.

Without the Sun, we would not be here.

We would be somewhere else, making our Star the centre of the Universe.

Thank the Lords of Kobol!

3. Origin of Life on Earth

Scientific field: Chemistry/Biochemistry
Techniques used: Miller-Urey type experiments...
Current theory:

The origin of life does not require an evolutionary theory.

It may be statistically improbable, but it only had to happen once. Scientists are already able to create complex organic components in the lab. They may be able to artificially assemble a single-celled organism soon.

However, the origin of intelligent life is still a big mystery.

Hopefully we will be able to learn more about it, once it happens.

4. Biological evolution (molecular)

Scientific field: Biology/Biochemistry
Techniques used: sequence analysis, genetic experiments...
Current theory:
Neutral Drift

I think Darwin has been unfairly singled out for criticism by creationists.

After all, it's partly Wallace's fault too.

Besides, creationists overestimate the reverence that scientists feel for Darwin.

Real scientists don't worship Darwin (as much as they worship chocolate).

If they did, then why did they throw out his beautiful blended inheritance idea in favour of an Austrian monk who probably falsified his results?

If they really worshipped Darwin, then why didn't they throw out the neutral theory of molecular evolution and remove all traces of it from modern biology textbooks?

Instead, neutral drift became the foundation of the molecular clock technique and modern population genetics.

Scientists continue to bicker over the relative importance of selection vs neutral drift at the molecular level.

Why were anti-selectionists like Kimura and Ohta accorded the kind of respect in the scientific community that creationists never got?

There could only be one reason.

"What do you mean, Doc? All the best stuff's made in Japan."

5. Biological evolution (phenotypic features)

Scientific field: Biology
Techniques used: animal models, molecular genetics, comparative anatomy, fossil record...
Current theory:
Modern Synthesis/Neutral Drift

One of the first criticisms I've heard about Darwinian natural selection is that it employs circular reasoning.

For example, when trying to explain a feature of an animal, for example a wing on a flightless bird:

"The reason why it exists is because it is adaptive! We know it must be adaptive because it exists!"

That's rather unfair to Darwin too, because he predicted the existence of selectively neutral characteristics right from the start. Pan-selectionists are a rare breed nowadays.

Natural selection is effective at shaping phenotypic features that impact survival and reproductive fitness, but not so efficient at removing features that don't matter either way.

In fact the harder we look, the more neutral features we find.

Take an onion for example. Why would it need five times more non-coding DNA than human beings?

Onions have layers!

Ogres have layers!

Yes, and parfaits are indeed delicious.

6. Biological evolution (population level)

Scientific field: Biology
Techniques used: animal models, molecular genetics, comparative anatomy, fossil record...
Current theory:
Modern Synthesis

What creationists don't seem to understand is that evolutionary biology has moved on quite a bit since Darwin's time.

This is why the current evolutionary theory is called the Modern Synthesis.

Which also means that any future improvements will have to be called the Postmodern Synthesis - philosophers rejoice!


Modern evolutionary theory differ from Darwin's original idea in three ways (from TalkOrigins):

a. It recognizes several mechanisms of evolution in addition to natural selection. One of these, random genetic drift, may be as important as natural selection.

b. It recognizes that characteristics are inherited as discrete entities called genes. Variation within a population is due to the presence of multiple alleles of a gene.

c. It postulates that speciation is (usually) due to the gradual accumulation of small genetic changes. This is equivalent to saying that macroevolution is simply a lot of microevolution.

While the modern synthesis accounts for much of the experimental data, occasionally we can find some bizarre organisms that present some interesting challenges.

For instance the vole. How did the ancestor of these small rodents manage to diverge into 60 species in just 2 million years - with all the descendants looking virtually identical?

There is reproductive isolation without much phenotypic variation - quite a mystery indeed!

A splendid opportunity to slog for many years in a lab, discovering new improvements to the modern synthesis.

Luckily for most creationists, they don't care enough about science to find supporting evidence for what they already believe.

7. Social and cultural evolution

Scientific field: Biology, Psychology, Sociology, Anthropology
Techniques used: social animal models, observations of social behaviour, archaeological findings...
Current theory:

In addition to their direct contributions to biology, Darwin and Wallace raised our consciousness (Richard Dawkin's favoured phrase) on the applicability of evolutionary ideas to other fields.

Naturally, the mechanism of cultural evolution is different from biological evolution. Here, Darwin's "survival of the fittest" meets Lamarck's "use it or lose it" and together they help explain how certain cultural behaviours spread so quickly and so widely.

Evolutionary ideas have been used in computer science and engineering as well.

Indeed they have become so integral to many aspects of modern science and technology that creationists have a long road ahead if they wish to refute all of these evolutions.

I suggest starting on non-coding DNA.

In the meantime, they should avoid all new drugs and technologies that are produced by evolutionary ideas, just to be on the safe side.

Would you like to know more?

Top ten misunderstood terms in biology
Top five reasons why science is t3h l33t
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