Human Evolution and Climate Change: We Will Survive

There is a lot of fear being spread around the world about global warming and catastrophic climate change. Some fools are even promoting a series of music events on all seven continents to promote their message that we must act now. They say the crises is upon us and the need is urgent to stop global warming.

Unfortunately these people always seem to ignore science, history, and even simple common sense. They rely on their feelings rather than reason and logical thought. Read this article about human evolution. Modern humans evolved, spread and thrived through ice ages, and every kind of natural disaster and climate changes, more severe than we are experiencing now. This is not mere speculation, but fact based on the study of written history and archaeology, (ancient Egyptians, Mayans, Aztecs, etc.). That is not all.

Now, as the following article explains, DNA evidence in human genes is showing how remarkably adaptable human beings are to changes in climate, diet, exposure to diseases, and probably everything else in our environment. Are we being unnecessarily frightened by current weather events and global warming? Only you can answer that question for yourself. Maybe it is just human nature to be afraid, to be cautious. Maybe that helps our survival. My advice is to not believe everything you are told or hear.
Peter

from: http://www.nytimes.com/2007/06/26/science/26human.html?pagewanted=1&th&emc=th

Humans Have Spread Globally, and Evolved Locally

By NICHOLAS WADE
Published: June 26, 2007

Historians often assume that they need pay no attention to human evolution because the process ground to a halt in the distant past. That assumption is looking less and less secure in light of new findings based on decoding human DNA.

People have continued to evolve since leaving the ancestral homeland in northeastern Africa some 50,000 years ago, both through the random process known as genetic drift and through natural selection. The genome bears many fingerprints in places where natural selection has recently remolded the human clay, researchers have found, as people in the various continents adapted to new diseases, climates, diets and, perhaps, behavioral demands.

A striking feature of many of these changes is that they are local. The genes under selective pressure found in one continent-based population or race are mostly different from those that occur in the others. These genes so far make up a small fraction of all human genes.

A notable instance of recent natural selection is the emergence of lactose tolerance — the ability to digest lactose in adulthood — among the cattle-herding people of northern Europe some 5,000 years ago. Lactase, the enzyme that digests the principal sugar of milk, is usually switched off after weaning. But because of the great nutritional benefit for cattle herders of being able to digest lactose in adulthood, a genetic change that keeps the lactase gene switched on spread through the population.

Lactose tolerance is not confined to Europeans. Last year, Sarah Tishkoff of the University of Maryland and colleagues tested 43 ethnic groups in East Africa and found three separate mutations, all different from the European one, that keep the lactase gene switched on in adulthood. One of the mutations, found in peoples of Kenya and Tanzania, may have arisen as recently as 3,000 years ago.

That lactose tolerance has evolved independently four times is an instance of convergent evolution. Natural selection has used the different mutations available in European and East African populations to make each develop lactose tolerance. In Africa, those who carried the mutation were able to leave 10 times more progeny, creating a strong selective advantage.

Researchers studying other single genes have found evidence for recent evolutionary change in the genes that mediate conditions like skin color, resistance to malaria and salt retention.
The most striking instances of recent human evolution have emerged from a new kind of study, one in which the genome is scanned for evidence of selective pressures by looking at a few hundred thousand specific sites where variation is common.

Last year Benjamin Voight, Jonathan Pritchard and colleagues at the University of Chicago searched for genes under natural selection in Africans, Europeans and East Asians. In each race, some 200 genes showed signals of selection, but without much overlap, suggesting that the populations on each continent were adapting to local challenges.

Another study, by Scott Williamson of Cornell University and colleagues, published in PLoS Genetics this month, found 100 genes under selection in Chinese, African-Americans and European-Americans.
In most cases, the source of selective pressure is unknown. But many genes associated with resistance to disease emerge from the scans, confirming that disease is a powerful selective force. Another category of genes under selective pressure covers those involved in metabolism, suggesting that people were responding to changes in diet, perhaps associated with the switch from hunting and gathering to agriculture.
(the article is continued at the original source)

Evolution- Tennessee and the Scopes Trial

On May 25, 1925, John T. Scopes was indicted in Tennessee for teaching Darwin's theory of evolution. He as later tried and convicted. The law in Tennessee banning the teaching of evolution was not repealed until 1967. Now, a mere 40 years later it is difficult to imagine NOT teaching evolution, the foundation of our Life, Earth, and Medical Sciences. This just shows how easily people are led by passion, and emotion rather than scientific fact.

Another person from Tennessee comes to mind. He is a former Vice-President and now the leading proponent of the grossly misguided stop global warming campaign. What is it about Tennessee that makes the people there so blind to reality? Maybe it is something in the water.
Peter

John T. Scopes
From Wikipedia, the free encyclopedia


John Thomas Scopes (August 3, 1900 – October 21, 1970), a teacher in Dayton, Tennessee, was charged on May 25, 1925 with violating Tennessee's Butler Act, which prohibited the teaching of evolution in Tennessee schools. He was in court in a case known as the Scopes Trial.
Scopes was born and raised in Paducah, Kentucky, but as a teenager attended Danville High School in Danville, Illinois (Danville High was also the first school he taught at shortly before he moved to Dayton). Scopes was a member of the class of 1919 in Salem, Illinois, which is also William Jennings Bryan's home town. After he had gained a law degree at the University of Kentucky in 1924, Scopes moved to Dayton where he took a job as the Rhea County High School's football coach, and occasionally filled in as substitute teacher when regular members of staff were off work.
Scopes' involvement in the so-called Monkey Trial came about after the American Civil Liberties Union (ACLU) announced that it would finance a test case challenging the constitutionality of the Butler Act if they could find a Tennessee teacher willing to act as a defendant.

A group of businessmen in Dayton, Tennessee, led by engineer and geologist George Rappleyea, saw this as an opportunity to get publicity for their town and approached Scopes. Rappleyea pointed out that while the Butler Act prohibited the teaching of evolution, the state required teachers to use the assigned textbook, Hunter's Civic Biology (1914), which included a chapter on evolution. Rappleyea argued that teachers were essentially required to break the law. When asked about the test case Scopes was initially reluctant to get involved, but after some discussion he told the group gathered in Robinson's Drugstore, "If you can prove that I've taught evolution and that I can qualify as a defendant, then I'll be willing to stand trial."


By the time the trial had begun, the defense team included Clarence Darrow, Dudley Field Malone, John Neal, Arthur Garfield Hays and Frank McElwee. The prosecution team, led by Tom Stewart, included brothers Herbert and Sue Hicks, Wallace Haggard, and father and son pairings Ben and J. Gordon McKenzie and William Jennings Bryan and William Jennings Bryan Jr. Bryan had spoken at Scopes' high school commencement and remembered the defendant laughing while he was giving the address to the graduating class six years earlier.


The case ended with a guilty verdict, and Scopes was fined $100, which Bryan and the ACLU offered to pay. The case was appealed to the Tennessee Supreme Court. In a 3-1 decision written by Chief Justice Grafton Green the Butler Act was held to be constitutional, but overturned Scopes' conviction on a technicality: the judge had set the fine instead of the jury. The Butler Act remained until 1967 when it was repealed by the Tennessee legislature.
Scopes may have actually been innocent of the crime to which his name is inexorably linked.

After the trial Scopes admitted to reporter William Kinsey Hutchinson "I didn't violate the law," explaining he had skipped the evolution lesson and his lawyers had coached his students to go on the stand; the Dayton businessmen had assumed he had violated the law. Hutchinson did not file his story until after the Scopes appeal was decided in 1927. Scopes also admitted the truth to the wife of the Modernist minister Charles Francis Potter. Scopes was not allowed to take the stand at his trial for fear he would reveal his ignorance and turned down a $50,000 offer to lecture on evolution on the vaudeville stage because he did not know enough about the subject.


John Scopes wrote an autobiography entitled Center of the Storm: Memoirs of John T. Scopes. (Henry Holt & Company, Inc. — June 1967), ISBN 0-03-060340-4
Retrieved from "http://en.wikipedia.org/wiki/John_T._Scopes"