The oldest participating DNA shows how the genus divides into new species, a” ghost line “that we would not recognize if it weren’t for their DNA
But humans are not. The only ones that have left DNA in their bones, and the same tests that work for humans may work for all other species groups, is a ghost line of mammoths that have distant relatives to the North American mammoths: the population, Wired said.
Mammoths share something with humans: how we started them when African populations spread across much of the planet During the ice ages, climates created the woolly mammoth and its close relative, the North American mammoth, called the Colombian mammoth, one of these species Named, however, it is extinct, and the only living members are elephants.
We receive DNA from two of these species, the woolly mammoth, and the Colombian. This resulted in a series of cold climatic adaptations and a low degree of interbreeding, as woolly mammoths made their way to North America and made a small contribution (about 10 percent) to the genome of the Columbia population.
The new work focused on Mammoth teeth in Siberia, where conditions favored both the preservation of the remains and the preservation of the DNA in them. The teeth come from layers of material that appear to have been deposited at the beginning of the last ice age when the ancestors of the woolly mammoth population should have been present in the area.
We do not have exact dates for any of the teeth as instead, they appear to be too old Data derived using a combination of the types present in the deposits and the known time of changes in the orientation of the Earth’s magnetic field.
Also, the shape of the teeth provides some clues as to which type of group they are with and some other clues as to when they were deposited. In total, one tooth is likely to be at least 500,000 years old, another about a million years old, and a third slightly older.
Before that, the oldest DNA obtained from animal remains is roughly the age of the youngest. of these samples. However, the researchers were able to recover some elephant-like DNA from each of the molars, even though it was heavily fragmented and many individual bases were damaged.
The researchers were able to isolate the complete mitochondrial genome for each of the three teeth because each cell contains many copies of this genome in each of its mitochondria.
However, at most nuclear genome fragments could be obtained, at most about 10 percent of a genome and in the worst case less than 2 percent (less than 2 percent is still tens of millions of individual bases).
Using the differences between mammoth and elephant DNA and assuming a constant mutation rate, the research team was able to derive data as to when each of the animals that left a tooth must have lived. Based on the genome of the mitochondria, the dates were 1.6 million, 1.3 million, and 900,000 years ago.
For the two who had enough core genomes to analyze, the dates were 1.3 million and 600,000 years ago. The DNA-based data of these two agreed very well with each other and the date of the material in which they were found.
The oldest sample could be older than the bond, so it could have been moved after death, that these mammoths lived in Siberia shortly after in Siberia, after the Ice Age, although before a clear mammoth line woolly. It also showed the familiar appearance of mammoths in North America.
For all of these reasons, genomes may have a lot to say about the history of mammoths, and they do. The two most recent samples are clearly in the same lineage that eventually gave rise to the woolly mammoth, although they obviously fall victim to the newer samples, which have more complete genomes. But the oldest from a place called Krestovka seems to come from a completely different lineage.
Although related to the woolly mammoth branch, it diverged significantly, with analysis indicating that the split occurred at least 1.8 million years ago. 40-440-4krestovka also has no direct modern descendants, indicating that it may have died as a population in its own right. But much of its DNA ran as part of the Columbia mammoth genome. Sometime after the Krestovka, the line was in INTERBRED with the ancestors of the woolly mammoths.
The result was a mixture of almost 50/50 of the genomes of the two branches, the descendants of those who migrated north. H America and formed the mammoth population of Colombia. It wasn’t until much later that it was reunited with the offspring that are now a characteristic woolly mammoth population when it was crossed in North America.
These animals were almost as well adapted to the cold as their offspring, the woolly mammoths. The researchers identified 5,600 cases where the proteins in the mammoth genome were different from those in elephants.
The largest mammoths had already seen more than 85 percent of these changes, including those related to hair growth, fat deposits, temperature monitoring, and day/night cycle management.
In other words, these things probably looked very similar to even woolly mammoths if they came from a population that at the time was still part of a larger group of mammoth ancestors.
Mammoths can be a relatively rare case as we have many of their remains and they lived in a part of the world where the conditions for DNA preservation are excellent. But they probably also had a long generation, so they submitted to the population.
Changes change much more slowly than many other species. EVEN Although this old man receives DNA, he’s rare. We may not need ancient DNA to obtain valuable information about how the species around us came into being. And it’s based on us and the mammoths. Digging into these stories can lead to many surprises.
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