Tag: dna

Barcode of Life

Mitochondrial genes are inherited maternally. They are not scrambled by recombination, and mitochondrial variation offers rough clues about evolutionary history. Insect people were using the back end of a mitochondrial gene known as CO1 to help identify specimens, marine invertebrate people liked the front end, and vertebrate zoologists used a different mitochondrial gene altogether. Hebert’s idea was that, out of a hodgepodge of related techniques, he could build a simple, universal identification system — assuming, that is, the same small piece of mitochondrial DNA worked reliably for all the animals in the world. “We believe that a CO1 database can be developed within 20 years for 5-10m animal species on the planet for $1b”

2020-12-18: Genomic Encyclopedia

Researchers announced a significant advance. They have assembled the largest catalog of microbes to date, containing over 50k genomes from 18k different microbial species—12k of which have never been documented before. Their study expands the known tree of life by 45%. They also found 700k viruses and linked them to their bacterial and archeal hosts, further illuminating the vast interconnections in this unseen world.

“It’s a fucking incredible amount of data. There are only ~10K species of microbes that have been cultured and described formally, and yet there might be 1B species. That is why this study is so important.”

2021-08-06: The database currently holds 10m barcodes mapped to 330k species.
2022-07-15: Evolution isn’t a tree

“If the evolutionary history of the hoatzin conformed to processes we already understand well, then we’d probably have already figured out what it is most closely related to. The fact that we don’t know its nearest relative suggests that there were processes involved that we still do not understand.” The hoatzin could have more than 1 set of closest relatives— “an unsettling prospect in the context of existing classification and in the minds of many contemporary biologists.”

This strange-sounding state of affairs is not unique to the hoatzin; we see it in our own DNA. Human beings share their most recent common ancestor with chimpanzees and bonobos, but more than 10% of the human genome is actually more closely related to the gorilla genome. Another tiny fraction of the human genome also seems to be most closely shared with an even more distant relative: the orangutan. “This implies that there is no such thing as a unique evolutionary history of the human genome. Rather, it resembles a patchwork of individual regions following their own genealogy.”

Samaritan Genography

recent archaeological findings, coupled with deeper examination of religious texts, have led researchers to propose that the Samaritans were Jews themselves. During the Babylonian Captivity, not all Jews were rounded up by the Assyrians. Some stayed behind, possibly marrying other Assyrian exiles who themselves had been relocated. This would make sense given that, even though Samaritans are not considered Jews, they share many of the same ancient Hebrew rituals. While these rituals have evolved for 100s of years among most Jewish sects, they remain unchanged among the isolated Samaritans, even to this day. This also fits well with the historical animosity of Jews toward Samaritans because of their association with non-Jews.

they need to do more of that to defuse the nonsense and irrational beliefs about “heritage” in the near east

7 Daughters of Eve

The 7 Daughters of Eve can be divided into 2 major parts. In the first, Sykes discusses some of his most fascinating work. He relives how he and his colleagues extracted ancient DNA from the 5000-year-old Ötzi the Iceman, examines his work on understanding the origins of the Polynesians, and tells how he and his team discovered the true fate of Tsar Nicholas II and the Romanovs. With each story, Sykes easily manages to explain the scientific details behind his conclusions in a way that nearly any reader can comprehend.

mitochondrial dna

Biotech Paternalism

California’s Department of Public Health has issued cease and desist letters to 13 genetic testing startups – most notably 23andMe. They are mandating that the labs demonstrate that they have been certified by both the state and federal government, and, perhaps more importantly, that all genetic tests were ordered by a patient’s doctor, which is required by state law.

completely retarded. overreaching legislation, as usual in the healthcare sector.