DNA Research TOC - 3/19/2013
evironmental conditions effect DNA and Evolution
-- Eight surprising facts about human evolution - 11/15/18
-- Land-ice melt at the end of the last five ice-ages - 9/25/14
-- Cholera is Altering the Human Genome - 7/3/13
surprising facts about human evolution
In Tracks: Chimera, the third series of Matthew Brighton’s conspiratorial thriller, the story of Helen Ash continues as she unravels a mystery with human evolution at its heart. But how much do we really know about the history and future of our species? Here are eight sometimes surprising things about our journey towards understanding the story of human evolution.
1. We didn’t evolve from apes
Contrary to the popularised image of mankind ‘arising’ from apes, modern humans – Homo sapiens – did not evolve directly from the apes alive today, but rather we share a common ancestor. Our evolutionary paths diverged from those of chimpanzees and gorillas about six million years ago. Though we do share over 90% of our DNA with them, apes are distant cousins, not great-great-great (etc.) grandparents.
2. You are actually less than half human
About 43%, to be precise. This much of your body is made up of human cells, while the rest is a mix of bacteria, viruses and fungi that combine to make your microbiome. This is thought to be as individual to each person as their fingerprint, and plays a role in many vital body functions from digestion to the immune system.
3. Darwin wasn’t right about everything
He’s best known for popularising the theory of evolution in his book, On the Origin of Species, but Charles Darwin also had some very unsubstantiated ideas about human beings... In a later book, he wrote that qualities like intellect and sense of smell were greater or lesser in different racial groups. He also thought that “the average of mental power in man must be above that of woman.” Needless to say, none of these claims have borne out.
4. We’re full of evolutionary leftovers
Evolution can be a slow process, and sometimes things stick around many generations after they’ve ceased to have a purpose. These leftovers, or vestigial traits, are found in human beings too. The appendix is thought to have been involved in digestion for our distant ancestors, but it seems to be largely defunct in the human body today. Many primates have wisdom teeth to grind down their fibrous food, yet ours appear to be getting crowded out as the human jaw gets smaller with a soft diet. However sometimes evolution finds a good use for vestigial organs. The coccyx or tailbone, formerly used for balance, is now an anchor for muscles.
5. Goosebumps are mostly useless
When our more hirsute predecessors were feeling cold, a useful reflex would contract tiny muscles at the base of their hair follicles, causing their coat to stand up and trap more air to keep them warm. The same response has remained in human skin through many evolutionary stages, but unfortunately these days the raising of the fine hair on your body does little more than remind you that you might need a jumper. Just think warm thoughts.
6. But morning sickness might have a purpose
Feeling sick all the time while you're trying to nurture a growing baby might seem like a terrible mistake on evolution's part, but what was for a long time thought to be an unfortunate side effect of pregnancy hormones could actually be a clever development. While animal products like meat and eggs are now safe to eat thanks to refrigeration technology, for early humans they would have presented a high risk of toxins in early pregnancy. Researchers now think that developing a strong aversion to these specific foods was actually a protective mechanism to avoid illness while the foetus was still in the early stages of development.
It is now thought that there wasn’t one single ‘cradle’ of humanity and that early humans likely evolved in multiple places at the same time.
7. Our species arose about 300,000 years ago
The story of our origin is constantly changing as new discoveries are made. In 2017, our history shifted by almost 100,000 years when a skull from Morocco became the oldest known example of Homo sapiens, surpassing the 195,000 year old record held by other remains from Ethiopia. It is now thought that there wasn’t one single ‘cradle’ of humanity and that early humans likely evolved in multiple places at the same time, all over Africa, and that we have much more yet to learn.
8. We’re not done evolving
We’re still adapting to cope with the world around us, and now scientists can track ongoing evolutions in human genes. Among British people, the gene for lactose tolerance has spread rapidly in the past 100 generations – or about 2,000 years – allowing more of us to drink cow’s milk. Our bodies will likely continue to develop alongside our changing way of life!
General DNA News TOC // Pa·le·o·an·thro·pol·o·gy [ pàylee ō anthrə pólləjee ]
The study of early humans and related species through fossil evidence.
- WEB They are installing a version 2.0. When I try to sign
in they pop up a Googlechrome ad that has no bypass on it. I called
them and they told me that my IE-8 is "out of date" it will not display the
new 2.0 web page. So they are pushing Googlechrome to replace
Microsoft IE 8 and prior versions. My OS is XP, XP can't process IE
version 9 or above. So we have Microsoft pushing their new OS 8 and
geographica pushing Googlechrome - a fine state of affairs for America.
National Geographic web site - National Geographic and IBM's Genographic Project Atlas of the Human Journey explores early human migration routes and describes the highlights along that journey. Allows direct access to the Time Line Eras, Journey Highlights, and Genetic Markers or Haplogroups that interest you most. Go there to learn more about ancient human migration through detailed text, photographs, maps, time lines, videos, and more. Oct, 2008: I have learned that these folks base all their output on 12 markers - It seems that 12 markers is all it takes to place a person into an ancestry group determined to have a specific geographic beginning.
Global Environment and it's effect on DNA Evolution
of DNA Terms // A fairly good assembly of DNA terms
Genome and General DNA News
I find it difficult to seperate DNA information by era therefore, I am now trying to assemble all DNA that is not directly related to myself or family into a DNA section of its own. Please bear with me as I work this out.
Did Most Men Die Off 7,000
STANFORD, CALIFORNIA—Live Science
reports that population geneticist Marcus Feldman of Stanford
University has proposed a new explanation for the
population bottleneck between
5,000 to 7,000 years ago detected in the genes of modern men, which
suggest that during this stretch, there was just one male for every 17
females. Feldman and his team conducted 18 simulations that took into
account factors such as Y chromosome mutations, competition between
groups, and death. The study suggests that warfare among people living
in clans made up of males from the same line of descent could have
wiped out entire male lineages and decreased the diversity of the Y
chromosome. In this scenario, there are not dramatically fewer males,
but there was significantly less diversity in their genes. “In that
same group, the women could have come from anywhere,” Feldman said.
The study found no bottleneck in mitochondrial DNA, which is passed
from mother to child. “[The women] would’ve been brought into the
group from either the victories that they had over other groups, or
they could’ve been females who were residing in that area before,” he
said, since the victorious male warriors may have killed all the men
they conquered, but kept the women alive and assimilated them. To read
about genetic adaptation to life at high elevations, go to “The
Heights We Go To.”
I had not heard of this specific “bottle neck”. The major “bottle neck” of population I have read about is dated 74,000 BC when the super volcanic eruption of Mt. Toba. I have no idea what this 5,000 – 3,000 BC bottle neck is about. Maybe I’ll look it up someday. If someone reading this will clearify please email me HERE and please specify bottle neck 3-5 BC.
Remember they are speculating this condition based on Y-DNA; for instance male 1 has no sons and can't pass on his Y-DNA, if he was the last of his group then his group Y-DNA will die out. That does not mean there are fewer males but rather fewer DNA groups of males. Notice also they don't include births - which could be extrapolated forward in but an 18 year period.
Mitocondrial DNA for instance
is down to 7 major groups.