Is DNA older than the Earth?
DNA, as the molecule that carries genetic information, is thought to have evolved later in the history of life on Earth, likely around 3 to 4 billion years ago. Therefore, DNA is not older than the planet itself.
The RNA world
Many researchers concur that an RNA world must have preceded the DNA-based life that now dominates. However, RNA-based life may not have been the first to exist. Another model echoes Darwin's "warm little pond" with cycles of wetting and drying. RNA is central to the translation process.
"We are working to uncover how molecules similar to RNA and DNA first appeared on Earth around 4 billion years ago," Hud said.
The oldest DNA recovered is over 1 million years old, but the oldest hominin DNA is only ~400,000 years old.
If terms like adenine and guanine bring back unpleasant memories of Genetics 101 here's one reason to give the words a second thought: A team of scientists has discovered that these and other DNA building blocks can form in outer space and have been deposited on Earth's surface by meteorites.
The evidence is overwhelming that all life on Earth has evolved from common ancestors in an unbroken chain since its origin.
Under favorable conditions DNA can survive for thousands of years in the remains of dead organisms. The DNA extracted from such remains is invariably degraded to a small average size by processes that at least partly involve depurination.
View that human life begins when sperm and eggs fuse to give rise to a single cell human zygote whose genetic individuality and uniqueness remain unchanged during normal development is widely supported. Because the zygote has the capacity to become an adult human individual, it is thought it must be one already.
Experiments suggest that organic molecules could have been synthesized in the atmosphere of early Earth and rained down into the oceans. RNA and DNA molecules — the genetic material for all life — are just long chains of simple nucleotides. 2. Replicating molecules evolved and began to undergo natural selection.
DNA found in Greenland has broken the record for the oldest yet discovered. The fragments of animal and plant DNA are around 800,000 years older than the mammoth DNA that previously held the record, with older sequences perhaps still to be found.
Who has the oldest DNA on earth?
The oldest DNA ever recovered has revealed a remarkable two-million-year-old ecosystem in Greenland, including the presence of an unlikely explorer: the mastodon.
The percentage of Neanderthal DNA in modern humans is zero or close to zero in people from African populations, and is about 1 to 2 percent in people of European or Asian background.
A new genomic study has revealed that Aboriginal Australians are the oldest known civilization on Earth, with ancestries stretching back roughly 75,000 years.
You're not completely human, at least when it comes to the genetic material inside your cells. You—and everyone else—may harbor as many as 145 genes that have jumped from bacteria, other single-celled organisms, and viruses and made themselves at home in the human genome.
The new findings fit well with the hypothesis that bodies like comets, asteroids and meteorites that bombarded early Earth seeded the young planet with compounds that helped pave the way for the first microbes. Scientists previously detected key organic molecules in carbon-rich meteorites found on Earth.
THE NEW HUMAN STORY
The DNA evidence showed that H. sapiens mated with groups including Neanderthals and Denisovans. It even revealed evidence of other “ghost populations” — groups who are part of our genetic code, but whose fossils we haven't found yet.
Modern humans originated in Africa within the past 200,000 years and evolved from their most likely recent common ancestor, hom*o erectus, which means 'upright man' in Latin. hom*o erectus is an extinct species of human that lived between 1.9 million and 135,000 years ago.
Scientists are exploring several possible locations for the origin of life, including tide pools and hot springs. However, recently some scientists have narrowed in on the hypothesis that life originated near a deep sea hydrothermal vent.
Not very long ago, a group of scientists led by AAAS Member J. Craig Venter announced that they had created synthetic life in the form of bacteria. In this announcement, he said, \This is the first self-replicating species that we have on this planet whose parent is a computer."
Yes, DNA can survive the cremation process, but it is often damaged or destroyed to the point where it cannot be effectively analyzed. The extreme heat and chemical reactions involved in cremation can break down DNA molecules. However, in some cases, small fragments of DNA may still be recoverable.
Does water destroy DNA?
Water is the most essential substance for life, but causes DNA damage via the release of purine nucleobases from DNA, termed depurination, and the hydrolysis of amino groups of nucleobases, termed deamination.
Above all, it depends on whether the DNA is exposed to heat, water, sunlight, and oxygen. If a body is left out in the sun and rain, its DNA will be useful for testing for only a few weeks. If it's buried a few feet below the ground, the DNA will last about 1,000 to 10,000 years.
We will likely live longer and become taller, as well as more lightly built. We'll probably be less aggressive and more agreeable, but have smaller brains. A bit like a golden retriever, we'll be friendly and jolly, but maybe not that interesting. At least, that's one possible future.
Eggs must be alive to be fertilized. Sperm must be alive to fertilize an egg. If either is not alive, you can't get a fertilized egg. So life begins before conception, not at conception.
And in Genesis 2:24 we are told “Therefore man shall leave his father and mother and be joined to his wife; and they shall become one flesh.” That is the DNA of the male joining with the DNA of the female to become a new and wholly unique human being.
