Victor Macgill on Wallace... continued.
White skin is advantageous in colder climates as it absorbs ultraviolet light from the sun and is better at making vitamin D. So, if all humans began being the same colour, those in the tropics who happened to have darker skin than others would be more likely to survive. The opposite is true for those living in colder climates. Those with a whiter skin have the advantage and are more likely to survive and have children. Over generations people will change to have the skin colour most adapted to their environment resulting in the different colours of skin that we actually see in the world.
Viruses are the problem that they are because they can adapt and change easily and they can have many generations in a short amount of time. Viruses adapt to changing environments very quickly and effectively. Whenever we find a more effective cure for a virus, it immediately starts using natural selection to modify itself to become resistant again.
Charles Darwin found a gypsy moth that landed on particular trees. Those moths that had similar colours to the tree were better camouflaged and tended to survive. Because of air pollution, however, the bark on the trees grew darker. The moths also changed colour in line with these changes. When the air pollution was finally brought under control, the tree bark lightened again and so did the moths’ colours.
Dog breeding is the controlled use of natural selection to create a dog that has the features desired by the breeder.
Over the millennia horses, cats etc have developed into all sorts of sizes, from some more like rats to others being very large, each adapted to the environment in which they must live.
So, evolution clearly does happen. The fossil record clearly shows it happens and in small organisms that can have many generations in a short period of time, we can actually see evolution happening before our eyes. That does not mean that there are not problems with the Theory of Evolution.
Darwin (and Wallace) made some significant errors in how they thought evolution worked. When you realise that in their time, nothing was known about DNA and genetics, they did pretty well. Much of Darwin’s original Theory has been modified over time in response to new discoveries in scientific knowledge not available in the 19th century. Even with these improvements, there are still problems that will not go away.
One of the key components of Darwin’s theory was that evolutionary change occurs slowly and evenly over extremely long periods of time. In actual fact the fossil record does not show this. It shows species of animals being significantly different suddenly appearing. Darwin assumed that in time more fossils would be found which would fill the gaps in the fossil record, but all this time later, though the fossil record is more full, the gaps are still there.
We would expect to find many transition species as animals evolve from one type to another. There are some such species as the archaeopteryx – half way between a dinosaur and a bird and the tiktaalik – half way between a mammal and a fish, but we should see many more if Darwin’s ideas are correct.
Gradual change explains well why a creature might get bigger or smaller, but it does not explain as well something like the evolution of a wing for flying. According to Darwin’s ideas the development of a wing would need many intermediate steps all co-ordinated together. Not only do feathers need to evolve but the bone structure must become lighter, the muscles must be different to facilitate a different range of motion and so forth. During intermediate steps there must have been a half a wing that would be no use to an animal. It would not allow the creature to fly and takes away the use of a limb that could otherwise be more usefully used. That would make the creature even less well adapted to its environment and highly likely to go extinct. The kiwi evolved from a bird that flew to New Zealand but once here, without significant predators, being able to fly was less important and so the wings shrunk back again until it could not fly.
Stephen J Gould and Niles Eldredge have proposed a theory they call Punctuated Equilibria. What that means is that most usually the environment remains stable, so there is no need for the species to adapt. Then eventually there will be a significant change and so change is needed, and that occur relatively quickly. The modern study of Systems Theory talks about tipping points. That says that often in a complex system the level of chaos builds slowly over time. For a long time the system can cope with the tension that results from the chaos and still remains stable because it can adapt to meet the challenge. Eventually, however, the system reaches the limits of its ability to adapt and it reaches a tipping point. At that point, the system either collapses quickly or quickly restructures itself significantly in a way.
In terms of evolution it would mean that the form of a particular creature can remain stable for a long time, in spite of prolonged pressure from the environment, but when the form just can’t cope with the stresses on the environment it will either go extinct, or change its shape quickly into a new, more complex form which is better adapted to that environment. This could explain why new forms seem to appear suddenly in the fossil record and how the eye and wing could form. When I say “suddenly” I mean suddenly in a relative sense, so we are still talking about thousands of years as compared to many millions of years.
Even so, it is a rather miraculous to form a wing. So many new forms need to be all co-ordinated to happen together. How does the creature know that a particular type of bone structure, highly developed feathers and pattern of muscles attachments will form a wing capable of allowing the bird to fly. Richard Dawkins has suggested that maybe feathers grew because of some other factor in the environment but then found they could be used to fly. I’m not sure what else feathers could be used for.
Many creatures have evolved traits or lost useful traits that do not appear to fit with natural selection. Snakes evolved to lose most hearing, a lions mane is an impediment to hunting and does not seem to have any other purpose, the short limbs of the Tyrannosaurus can not have been very useful and the three linking bones in a human ear are unnecessarily complicated.
There is also the problem that all the main forms of life evolved into species early on in the history of life and while there has been much variation within species, no brand new species have evolved. Once a species is formed it remains amazingly stable, while there is much variation within the species.
Darwinian evolution says there is no purpose to evolution; that everything is just the response to becoming more effective at living in any given environment. So, why does life relentlessly move towards higher levels of complexity? A part of the answer as to why nature evolves towards greater complexity is that two similar creatures competing for the same resources in an environment will be adapting to become more efficient by becoming more complex. In general the more complex creature will outlive the less complex. Is that enough to explain the relentless march towards complexity?
Why are we not swamped with less evolved forms since they are easier for nature to create? It would be easier for nature to just fill the earth with plants, but evolution just keeps moving on creating more and more wonderful and complex types of life.
The three times that Alfred Russell Wallace talks about when there must have been some form of divine intervention, may well have been tipping points. Gould and Eldredge’s Punctuated Equilibria can explain the tipping points, but is that enough for evolution to have evolved in such a directed way?
Because scientists have to face the powerful creationist lobby, they are often too cautious to declare their doubts about evolution from a scientific viewpoint. The basic nature of the universe set out the limits of what can be and what can not be. If we accept the proposal of many ancient spiritual traditions and scientists like Ervin Laszlo, then the fundamental structure of the cosmos is conscious or indeed taking the Spiritualist principle that the Source of all is Universal Love, then the stage is set for a journey through time whereby the consciousness of the universe is made manifest through the process of evolution.
Ervin Laszlo talks of quantum coherence discovered by scientists looking at quantum mechanics. He says that woven through the very fabric of the universe is a coherence, a connectedness that allows different parts of the universe to co-operate. We might be more tempted to call quantum coherence something like divine energy.
Madame Blavatsky, who founded the Theosophical movement actually first used the term “intelligent design”. That term has been misused by those who would have a literal reading of the bible, but if we see that intelligent design working in a different way, as quantum coherence or divine energy using evolution, maybe intelligent design describes another part of the jig saw puzzle that describes life as we know it.
I believe the ideas of evolution and creationism need not contradict each other, especially if we look at creation as an ongoing process rather than a one-off event. The fundamentalist picture of creation is a creation that is fully created with everything ready to go from the start. We can rather see creation like bringing up a child, where the seed is sewn, which must then grow and develop itself, albeit with the help and support of the parents.
The idea of creation being a process is reflected in the first words of the Bible. Genesis 1:1 says, “In the beginning God created the heavens and the earth.” Of course this is a translation of the original Hebrew, which begins, “Bereshit bara Elohim.” Bereshit means “in the beginning”, “Elohim” means God and Bara is the verb, to create. Bara is usually translated as “created” because that makes sense in English, but a more accurate translation is, “In the beginning God is creating the heavens and the earth.” In other words creation is seen as an ongoing process, not a one-off event. Rather than seeing God as standing outside of his creation and setting it off, we can see God as part and parcel of the ongoing creation. Evolution becomes a spiritual process. This way of looking at life also God and God’s creation are one. Since we are a part of God’s creation, then we also must be a part of God. God is in us and we are in God and we evolve to co-create our universe together