How did humans come to exist?

How can something as complicated as ourselves happen by chance? The answer: Order comes naturally from chaos over time in a universe where order is rewarded on small scales by local forces such as atomic attraction.

It has taken more than five decades, but the electronic computer is now powerful enough to simulate evolution.

Researchers from Michigan State University have used software to prove Charles Darwin’s postulation that small, seemingly inconsequential changes over thousands of generations can result in the evolution of complex functions.

They also uncovered a twist on conventional evolutionary thinking — it seems that some mutations that are harmful in the short run may boost long-term potential.

… When digital organisms were rewarded for solving simple puzzles with more CPU time — and thus an increased ability to send their genes forward to future generations — they eventually evolved a way to solve even the most complex problem they were challenged with, said Lenski.

The researchers’ results also show that this is the only way organisms can evolve, said Lenski. “Calculations imply [that] the probability of the digital organisms getting that complex all at once is astronomically small,” he said.

The birds-eye view on evolution also showed a twist, said Lenski. “Biologists usually assumed that the evolution of new mutations is an uphill climb — one in which the winners are descended from the most fit organisms in earlier generations, rather like a mountaineer that is always moving up — or at least sideways,” he said.

The researchers found that among the ancestors of the eventual winner, some had mutations that were harmful in the short run. Taking two steps back sometimes provided a better route. “Some of these harmful mutations worked well in combination with other mutations that came later,” said Lenski. So while most deleterious mutations were eliminated, some were passed on, turning a short-term handicap into a long-term advantage as the subsequent evolution unfolded, he said. – trnmag

In other words, it is highly likely that previous human species were more adanced in some ways that we are today. (For example, some may have had perfect memory. Others, amazing strength. Some may have been able to turn sugar into vitamin C….) In the future we may have samples of DNA from other human species we can use in hacking our biology.

Well, in the example above we had computer programmers who were “God” and they supplied the reward (CPU time). Doesn’t this prove by analogy that we have a God who supplied the reward (energy for reproduction and survival in a hostile environment) for the creation of humans?

The fairly new science of self-organizing systems has in part answered this. It is the small local rules, for example, charges which cause atoms to partially attract or repel, which eventually lead to large scale complexity. Once you have sufficient complexity along with random change, feedback loops emerge.

Complex systems with feedback loops that allow for self-renewal are called autopoietic structures. One example of a simple, self-organizing system is a whirlpool. Another example is the red spot on the planet Jupiter.

Simple autopoietic structures interact with new rules and eventually become more successful at reproducing, and thus, you get…

Other systems, such as the human body, can be extremely complex (Briggs and Peat, 1989). – Read More About Feedback Loops

PS. Here are some “artifical life” programs you can play with.

The Other Human Genome

Mitochondria are the focus of new research on Alzheimer’s, Parkinson’s and diabetes

Two decades before the human genome was sequenced, a human mitochondrial genome was sequenced. Mitochondria are the indispensable energy producers of human cells who live outside the nucleus and have their own DNA, genes and proteins. The mitochondrion sequenced in 1981 became known as the Cambridge reference sequence and has been used extensively in research. A few years ago, scientists re-sequenced the DNA to eliminate minor errors. …

A team led by MitoKor scientists built the database to discover mutations in mitochondrial DNA associated with human diseases and develop novel therapies. The loss of energy production can be disastrous for cells and has been blamed for a range of disorders. The MitoKor team aims to discover risk factors for Alzheimer’s, Parkinson’s and adult-onset diabetes, among other diseases, by comparing mitochondrial DNA from patients and healthy individuals.

“We will use the database to look as definitively as one can at the role of mitochondrial DNA in several of the major diseases,” says Neil Howell of MitoKor, who led the study. Making the connection between mitochondrial DNA and neurological disorders that occur late in life will not be easy, Howell adds.

I found this map completely fascinating. If this is accurate, humans have been in Europe 20,000 years longer than in North America.

Relative to the human genome with its three billion letters of DNA, the human mitochondrial genome is tiny—about 16,500 base pairs long. … The origin and dispersal of modern humans, Homo sapiens. The time of origin of modern humans is not well known but may have been about 200,000 (130,000-465,000) years ago. New evidence from mitochondrial genomes bolsters the hypothesis that the place of origin was sub-Saharan Africa and that the dispersal from Africa occurred within the past 100,000 years. The earliest known fossil and archaeological evidence on each continent, shown on the map, is consistent with this view.

©Nature – gnn

Some of my religious friends think scientists only believe humans evolved due to the few “missing link” fossils. Not true. The fossil record is a great reason, but there a number of others: comparative anatomy, geographical distribution and migration over time of species, the universal nature of biochemical organization, computer models and observation of the occurrence of new species.