The greatest show on Earth - The evidence for evolution.

Richard Dawkins, 2009. (Amazon review: 5 out of 5 stars)

 

- Or: Nature is utterly amazing.

January 17th, 2010 - by Simon Laub - Email: slaub@csc.com

This page as plain text.

Many flowers guide bees in to land by little runway markings, painted on the flower in ultraviolet pigments,
which the human eye can't see. Why - Because for the flower, insect pollination represents a huge advance in
economy over the wasteful scattergun of wind pollination.
Insects on the other hand, by choosing the most attractive flowers to visit, breed for floral beauty,
while the flowers breed the insects for pollination ability.
Obviously, according to evolution, the wonderful spectacle of the flowers and the bees came about
as an evolutionary process.

Evolution is a falsifiable theory, and therefore a scientific theory. Mammals haven't be around for all of the
Earths history - so you wouldn't expect to find mammal remains in old Earth layers, like e.g. Devonian rock.
And indeed no one have. If someone were to find a mammal in say Cambrian rocks, evolution would be
blown apart. In the words of J.B.S. Haldane: "Fossil rabbits in the Precambrian is no good"
(for the theory of evolution).

Instead, the world is just stuffed with evidence for evolution - and this book goes through a lot
of this evidence. And quite a treat it is.

Obviously, we can debate for ever what ''fact'' and ''evidence'' really means. In the book
a ''fact'' is defined as something that really occurred, or is known to be true by observation or authentic testimony.
Biologists, and Richard Dawkins in particular, seems awful sure about what is fact and what is not.
No ''Avatar 3d confusion'' [1] here!
Physicists on the other hand, through quantum physics and more, live in a world where ''fact'' is a somewhat
slippery concept. Trained in mathematics myself - mathematicians tend to believe in abstract beauty, which is ''fact'',
whereas the world around us is a fata morgana you can believe in or not. Depending on the time of day....
or if you have some mathematics at hand that can explain what you see.
So, my only grievance about this book (and other books by Richard Dawkins), is his ''religious'' belief
in certain ''facts'' and his vendetta against people who doesn't believe in these true ''facts''.
In the world of evolution, surely you should be able to believe that the Moon is a green cheese,
if that helps you survive.
No reason to be so upset!?

But with so much at stake, our entire existence actually, passions run high.
Take eugenic breeding of humans. The book doesn't say it is impossible (everyone agrees that it is immoral).
On the contrary - you could breed a race of superior body builders, pearl fishers .... and much worse ...
superior musicians, poets and high IQ people.
And if evolution say you could probably do that - would you then rather believe in something else? In Richard Dawkins
words: "Upholding the origin myth of a particular set of Bronze age desert tribesmen" ?

The mind numbing big numbers.

The secret of evolution is the mind numbing big numbers. Take bacteria. The E.Coli is a common bacterium.
Very common. About a billion of them are in your large intestine at this moment. Harmless or even beneficial
- they are a part of ''you''. How this weird ''you'' came about is explained by evolution though the
mind numbing eons of time.

What is a million years? In human terms it is app. 45.000 generations. Which takes us back to the days of the Homo Erectus ...
a time where we were not even Homo Sapiens...
Some 100.000 years ago a roving band of Homo Sapiens - looking pretty much like us - left Rift Valley, Africa and diversified
to all the races we see today.
The Turkana Boy [2] of some 1.6 million years ago would have been 1.8 meters tall (as an adult) and have had a brain
of about 900 cubic centimetres (cc). Typical for Homo erectus [3]. Larger than the earlier Homo habilis [4] (600 cc),
which in turn is larger than the earlier Lucy - Australopithecus [5] (400 cc).
The human story, from 3 million years ago to recent times, is a tale of increasing brain size.

Only local plans.

But according to evolution, there is no overall plan of development, no blueprint, no architects plan.
All is achived by local rules implemented by cells. Cells interacting with other cells on a local basis.
Inside cells, local rules apply to molecules, proteins, interacting with other molecules.
The nervous system wires itself up, not by following an overall blueprint - but by neurons
axons seeking out end organs with which they have a chemical affinity.
Local units following local rules. Cells that bristle with ''labels'' that enable them
to find their ''partners'' (Sperry [6]).

The genes that survive are those that are good at building bodies. Sexual selection, social environments, ecology and what have
you,determines what is good and what is not so good !
What survives and what doesn't gives the small steps of change that eventually gives the big changes.
In evolution, explanation always starts with the small steps!

E.g. Lemurs live in Madagascar. Nowhere else. The story is not that when Noahs Ark landed at mount Ararat in Turkey - the lemurs all decided to walk down to Madagascar
(swimming the last stretch to the island). Believing that story is a ''big step''!?
No, the lemurs is of course a long story of small changes according to evolutionary rules from some predecessor animal.

E.g. The evolution of the human skull is a series of changes in the rates of growth of some parts relative to other parts, controlled by genes in the developing embryo (D'Arcy Thompsons
transformations).

D'Arcy Thompson's skull transformations. How enlargement of one part of the skull compared to other parts leads to new designs. I.e. how genes in the embryo control growth of some parts relative to other parts.

''Design'' of the human eye.

Not necessarily leading to the best design - just ''good enough''.
Take the eye. Apparently designed by a complete idiot :-) Where the photocells point in the wrong direction, making it necessary for the wires that carry their data to pass through the retina and back into the brain.
Leaving a hole - the blind spot - which takes a lot of ''photo shop'' brain software to get rid of again.

 

 

 

 

 

 


The human eye - designed by a complete idiot?

The wires connecting the photocells to the brain run all over the surface of the retina, so the light rays have to pass through a carpet of massed wires before they hit the photo cells.

Worse: The photocells point in the wrong direction, making it necessary for the wires that carry their data to pass through the retina and back into the brain. In the vertebrate eye, all wires converge on a particular hole in the retina. Leaving a hole - the blind spot - which takes a lot of ''photo shop'' brain software to get rid of again.

 

No designer would plan a design like this up front. Only history and evolution could end up here.
And so it is, with a lot of what we see in nature. If forests were designed - they could be much smaller.
I.e. trees in a designed forest of ''friendship'' could agree to be only 10 feet tall. Much more efficient
than the uncontrolled (not designed) competition for sunlight that makes forest trees a 100 feet tall.

''Undesigned'' evolution.
The greatest show on Earth.

-Simon

Simon Laub
www.simonlaub.net


The Greatest show on Earth
- The evidence for evolution.
Richard Dawkins 2009.

Amazon review January 17th 2010.
(Five stars out of five).

Posterous: [7].