Monthly Archives: October 2007

10% of the Human Genome under selection

Living beings bear with various pressures for survival and such pressures during course of time cause various changes. Even Human beings are not untouched by these pressures. According to a Cornell study which compared genomes of various ethnicities of humans “natural selection has caused as much as 10 percent of the human genome to change in some populations in the last 15,000 to 100,000 years, when people began migrating from Africa.”

The study focused on hot spots on our genome such as skin color which is very different among populations but very similar within a population. Interestingly, the skin pigmentation genes used in this study reaffirms the “Out of Africa” theory long supported by most Anthropologists and Geneticists. While there were changes in skin genes, genes in brain development showed no differences. This was a major and hopefully the ultimate slap to those who still believe Multiregional Hypothesis—that Humans originated in various parts of the world and did not migrate out of Africa (this used to be the basis upon which slavery was implied).

According to Carlos Bustamante, a co-author of the paper,  the changes in human genome does not mean that a particular population is more evolved or superior to another rather it indicates how humans have adapted to their newer environment, developed digestion of newer sources of food, and how they have developed resistance to local infectious pathogens.

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Neanderthals Human interbreeding is possible

There is no doubt that today we know by virtue of fossils and genetics that Human species evolved in Africa and gradually moved out eventually conquering the world. Fossils have also indicated that multiple species of humans roamed across the world until recently.

It is a general consensus that Neanderthals existed in Europe 400,000 years ago, reached western Asia 150,000 years ago then went extinct 30,000 years ago. How far did the Neanderthals conquered? Did the Neanderthals really go extinct? What caused their extinction—was it the Ice Age brought by Toba volcano some 75,000 years ago? Or was it the fury of this newer more intelligent species, the Homo sapiens (Humans) that doomed the older bipedal ancestors? Or was it interbreeding of the two hominid species that united them to weather the Ice Age?

 What caused extinction of Neanderthals?
There is a consensus that eruption of super volcano Toba (Indonesia) and the Ice Age that followed has impacted human evolution like no other events. The numbers of Homo sapiens dwindled down to less than 10,000 and no other hominid fossil have been found post-Toba eruption. Although it is currently believed that Neanderthals went extinct because they could not compete with Humans for food, an argument can be made that they might have been integrated with modern humans for survival.

Even though the lack of fossils post-Toba eruption indicates that the only humans to exist were Homo sapiens, there has not been any conclusive evidence demonstrating that the remaining Homo sapiens directly or indirectly forced the remaining Neanderthals to extinction. While Neanderthals were archaic compared to Homo sapiens, they had developed language and culture. Thus it may be safe to assume that they interacted well with Homo sapiens. It seems logical to believe that two similar species, both possessing cultural values and ability to speak languages might have come together at time of dire straits to ensure survival. In the course of survival, they might have interbred with each other and if that was indeed the case, then Neanderthals might not have gone extinct. They might be within us, in our genome.

What leads me to believe that Humans and Neanderthals interbred?

There were two major papers recently published—first by Noonan et al in Science and another by Green et al in Nature. Both papers were about analyzing the Neanderthal DNA and a third paper by Wall et al was published in PLoS Genetics, which cautioned readers about the validity of the previous two papers. Wall found “possible contamination” of human DNA in sequences offered by both the papers. What Wall believes as contamination could be the result of human inbreeding with the Neanderthals.This idea of humans and Neanderthals inbreeding might seem bizarre but there is nothing that argues against it. May be one day some genetic study would convincingly prove that humans and Neanderthals did not breed but until then there is always a chance that Neanderthals prevailed by transferring their genes to us.

How far did the Neanderthals reach?

 Although newer findings are revealing more about the Neanderthals, there is yet another question to be answered—how far did the Neanderthals reach? Johannes Krause suggested in journal Nature that Neanderthals had reached “Uzbekistan and in the Altai region of southern Siberia.” With discoveries of newer fossils we are discovering that Neanderthals had reached much farther than we initially thought. Interestingly, no one has looked south of Hindu Kush for Neanderthal fossils. A presumably Ramapithecus mandible was found in Nepal. Ramapithecus was much older than Neanderthals. May be the Neanderthals reached the Foothills of the Himalayas too?

In addition to lack of interest, the lack of search for Neanderthals in the Indian Subcontinent might have been discouraged because not many fossils have been found in that area. But I have always wondered if the eruption of super volcano Toba has anything to do with it. May be the Neanderthals existed in the Indian Subcontinent and got buried below the ashes of Toba. May be if we dig deeper in the soils of the Himalayas we can discover that Neanderthals roamed there before their fate was sealed by Toba. I am not an archeologist so my suggestions to look for Neanderthals in the Indian Subcontinent may sound bizzare to some.

But these question still remain unanswered: how far did the Neanderthals reach and did they really go extinct or did they simply passed their genes on to us? Hopefully genetics and archeology can answer these questions in near future.

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On Religion

Are you a Christian? Why not? People ask me this question a lot. But as far as I know, there are very few people today who call themselves Christians. According to a recent Time magazine article, the image of Christianity is deteriorating in US. Majority of Americans, some 83% identified themselves as Christians just a decade ago but today, those who hold a ‘favorable view’ of Christians are dwindling down. The numbers will dwindle even lower, the article predicts because the younger generation are increasingly identifying themselves as non-Christians.

 Christianity has changed a lot in the US in last decades; while President Carter’s claim of being a Born-Again Christian contributed to his loss in Presidential elections, President Bush caters mostly to Born-Again Christians. American Christians are becoming more fundamental—meaning that they are interpreting the Bible literally rather than implementing the moral behind it. This increasingly fundamental Christianity of US lacks tolerance, it is impotent to change with time, it has uncompromising attitude towards newer scientific concepts, and it sends contrariant messages; thus any worldly and open-minded person has hard time supporting it. 

The TIME article mentioned above underscored the Church’s views on anti-homosexuality. But the modern American Christianity is also intolerant of other faiths. May be it has always lacked tolerance against other faiths but people seem to be more intolerable than before. May be the war on terror has changed Americans’ views of Islam and other religions. But it needs to be understood that it is not Islam but a few leaders of Islam who advocate Jihad that are the roots of terrorism. Besides US has contributed heavily on creating these Jihadists. Saddaam Hussein, Osama Bin Laden, Ayatollah Khameini are a few radical Islamists who exist due to US contributions to their respective countries at some time in the past. It is not Islam or any other faith but the American past that is haunting US today but the blame goes to Islam.

 

In addition to lack of tolerance, American Christianity is impotent to change with time. With the rise of fundamental Christianity in the US, basic rights such as abortion is in jeopardy. A woman should be able to choose whether she wants to give birth or not. Fundamental Christians are not willing to allow abortion even if the mother’s life is in jeopardy. And they do not support abortion even if a girl was a victim of rape. I do not think Jesus ever advocated for forced childbirth. Did he?

 

Modern Christianity of America has also not been able to keep pace with scientific technologies. Not that the Church has ever greeted science with open arms (poor scientists who argued with the church regarding the shape of the world) but American Christianity seems to reject modern ideas such as stem cell technologies with increasing scrutiny and this rejection is causing American scientists to pursue their career elsewhere. The most bizarre logic of fundamental Christians that is hard for me to understand is that why is it okay to kill the embryos by throwing them away but it is not okay to use them for stem cell research which can actually assuage people? How can such obtuse thinking attract modern youngsters?

 

In addition to its rigidity, various sexual allegations and confusing messages the church is sending out is not helping improve its image. There are overwhelming sexual allegations against the priests and ministers of the Catholic Church that every parent will think twice before sending their kids to church. When parents do not send their children to church, the numbers of Christians will obviously dwindle. Some desperate measures implemented by churches across the country to attract more young peoples include using the videogame Halo, according to the NEW YORK TIMES.This recent policy of the Church has ticked off the parents who shouted their lungs off to ban the action pact video game Grand Theft Auto. So, violence used by videogame companies to make profit is condemnable but the same used by the church for recruitment purposes is commendable? Why? I bet Jesus himself would condemn this move of the church.

 

I believe Christianity is not bad as a religion. I do not condemn the Bible or Jesus. I believe it is good thing to have faith. Belief in Faith makes one stronger and more powerful but doing bizarre things in the name of Faith is simply stupid. One should make intelligent decisions and stand up even against their spiritual leaders when things start going wrong. One should change with time or else one goes extinct.  If fundamental Christians remain so rigid and uncompromising, they too will be extinct.

 

I wish there were a religion that would look that people’s actions but not judge people on the basis of their appearance and lifestyle. I wish there were religious leaders who were compassionate enough to distinguish between right from wrong and smart enough to find innovative ways to incorporate science and technologies into religion such that both could move forward. I wish there was a religion that would be so right and so cool that it did not have to implement draconian measures to attract people.

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Filed under My Life My Thoughts, On Religion, Other