Investigating Spread Human Ancestors in The World from DNA Traces

With DNA testing (Deoxribo Nucleic Acid) using Y chromosome, a man today can trace his ancestors from  father's line, as well as mitochondrial DNA testing, a woman can find out her ancestors from mother's line.

IPHEDIA - More than a million years ago creatures standing tall had lived and spread on earth. They initially walked rather hunched over with a large lower jaw and eyebrow protrusions that made their faces look like apes.

19th-century evolutionists say that they are ancestors humans who currently rule earth. The results of the reconstruction and comparison anatomy of fossil bones found in a number of locations in Europe, Asia and Africa are basis this assumption. For example, a portion skull, teeth and upper femur was found by Eugene Dubois at Trinil, Ngawi in 1890 and named Pithecanthropus Erectus.

Based on research, remaining fossils from middle Pleistocene era, estimated to be around 1.5 million years old, add to collection ancient human fossils from hunts evolutionist paleontologists in uncovering missing link linking ape family line to Homo sapiens, modern humans living today.

However, nearly 1.5 centuries have passed, findings fossil specimens from various locations are still not able to explain assumptions Darwin's theory of evolution about common ancestor of homo sapiens and hominids, even though this theory has become an important part of biological buildings.

On other hand, genetic science is now in rapid development and seems to add to list questions to previous theory evolutionary tree which is a branching diagram of living species based solely on anatomy.

Tracked Through Genes

A decade ago human genome was mapped. Origin and traces spread of humans can already be traced through genes. With DNA testing (Deoxribo Nucleic Acid) using Y chromosome, a man today can trace his ancestors from father's line, as well as mitochondrial DNA testing, a woman can find out her ancestors from mother's line.

In each nucleus of a human cell there are 23 paired chromosomes, each of which has a twisted structure containing genetic information containing more than three billion letters of DNA in form of groups of phosphates, sugars and basic nitrogen.

Humans are estimated to have around 30-35 thousand trait-carrying genes per cell that continue to be passed down from one generation to the next through thousands of years without much change.

DNA research conducted on more than a thousand people from various ethnicities concluded that ancestors modern humans refer to a man and a woman (Adam and Eve) who came from one point in East Africa, which if traced to 100-200 thousand years old.

The continent of Africa is home to oldest gene carriers, while people outside Africa such as Europe, Asia, America, including indigenous people of Australia and Papua, only refer to genes as old as 50-70 thousand years ago.

From there it was concluded that during this period a number of ancestral groups in East Africa then migrated gradually out continent, over Arabian peninsula bridge and spread throughout world.

Based on an analysis thousands of DNA samples conducted by a team genetic experts led by Spencer Wells,  migration common ancestors Eurasian people (out of Africa) is divided into a number of branches.

The first branch in the map of human distribution, it is known that ancestors from east Africa headed north in Middle East (45 thousand years ago) settled for a long time and then there were generations who migrated again to North Africa and then some of them to Southern Europe. This migration process has been gradual for thousands of years.

Another branch, some headed for Central Asia 40 thousand years ago, from where, the next offspring began to pave the way north. Some of them turned west (35 thousand years ago) mixed with groups from Middle East to become ancestors of Europeans, some went northwest to Russia and turned to spread in Scandinavian region.

This Central Asian pioneer in genetic atlas then spread to South Asia and Indo-China and then turned north again to spread in East Asia. Another branch headed north in Siberia and became eskimos (15,000 years ago), some crossing as far as Americas, descending Indians.

Long before that, 50 thousand years ago there was also a group of people who came out of Africa, passed the southern coast of Yemen to the south of India, then to the northeast (Indo-China) and continued into East Asia.

There is also a branch from southern India that crosses coast to Sumatra, Java and into the Australian Continent and Papua mainland. Another branch that had settled in Sumatra then headed north towards South China Sea, which before before melting ice age was still mainland, and Kalimantan which at that time was also still one with Sumatra Island and Java.

They are expected to continue into what is now the Philippine Islands, some are spread to Japanese Islands. Some of them turned to mainland China mixed with Central Asian descent and some went north crossing to North America to become Indians that we now know.

Spread of Homo Sapiens

The spread of homo sapiens to various parts world whose path is like tangled yarn takes place gradually over a period tens of thousands of years with almost no change in genetic variation.

It seems that genetic studies have not been able to link homo sapiens genes with hominid genes as depicted in the evolutionary tree, let alone this human predecessor whose genes reached millions of years before humans (homo sapiens) first appeared.

The results of Svante Paabo's research from Max Planck Institute for Evolutionary Anthropology about presence neandertal-derived genes (which appeared earlier around 500 thousand years ago and became extinct 30 thousand years ago), amounted to 1.8 to 2.6 percent in all humans outside Africa is also still being debated.

Some parties such as Andrea Manica of the University of Cambridge reject statement possibility mating between two species and make sure that it could be only part of genetic similarity.

Other genome expert Tony Capra who examined genetic variation data from 20 thousand Africans said that neandertal gene passed down to homo sapiens was not unique, because it was also found in ancient genes of African ancestors, such as in Yoruba, Esan and Mende tribes, but had been lost. when descendants of ancient Africans migrated outside continent.

Africans do have more genetic variation from one tribe to another and become a hiding place for alleles (genes with varying nature) that cannot be found in people outside of Africa, while human genes that live spread outside Africa are very homogeneous.

However, genetically all humans on Earth are from the same ancestor and are very identical, where the genetic variation between individuals is not greater than 0.1 percent.

Thus there should not be a race that feels superior to other races, for example the Caucasoid race feels higher than the negroid race which actually becomes its older sibling, because all humans are actually in a homo sapiens race.

The greatest known genetic variation between humans is between two different sexes, male and female, which is around 1-2 percent. With this difference humans can survive by producing offspring and multiplying. (US)

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