Ancient DNA I

choi

(1) James Gorman, Prehistoric Dogs: In Siberia, a Meeting of Carnivores May Have Led to the First Game of Fetch. New York Times, Feb 2, 2021
https://www.nytimes.com/2021/01/ ... Siberia-wolves.html

The first 3 ⅓ paragraph:

"Twenty-three thousand years ago, in the cold of the last ice age, some humans found a place where the climate was marginally better: Siberia.

"While many people associate the region that is now in Russia with forbidding cold today, climate data as well as archaeological and DNA evidence show that this was where horses, mammoths and other prey animals found enough to eat, which attracted humans and other carnivores. Hemmed in by worse conditions, the humans, some of them the ancestors of Native Americans, were isolated for thousands of years. So were wolves.

"It is there and then that dogs were first domesticated, according to a new hypothesis from a group of archaeologists and ancient DNA experts who specialize in the deep history of humans and canines. They published their analysis on Monday [Feb 1] in Proceedings of the National Academy of Sciences.

"Angela R Perri, an archaeologist at Durham University who studies the domestication of dogs[, was the lead author] * * *

Note:
(a) The title refers to human owners play with their dogs, throw a thing out and tell dogs to "fetch." They could happen only after dogs were domesticated.
(b) Perri AR et al, Dog Domestication and the Dual Dispersal of People and Dogs into the Americas. PNAS, 118: _ (Feb 9, 2021 online publication)
https://www.pnas.org/content/118/6/e2010083118
(c)
(i) I fail to find the climate outside East Siberia back then.

Fedotov AP et al (a Russian team), Climate Changes in East Siberia (Russia) in the Holocene Based on Diatom, Chironomid and Pollen records from the Sediments of Lake Kotokel. Journal of Paleolimnology, 47: 617 (2012)
https://link.springer.com/article/10.1007/s10933-012-9586-5
("The [biogenic] proxy records were divided into four periods (A, B, C and D) suggesting differing climate in East Siberia during the Holocene. Period D (12.2–9.5 kyr BP) at the beginning of the Holocene, according to chironomid and diatom records, was characterized by warm climate with summer temperatures close to modern. However, forest vegetation had not become fully established yet. During Period C (9.5–5.8 kyr BP), the climate seemed to gradually become colder and wetter from the beginning of Period C to 7 kyr BP. From 7 to 5.8 kyr BP, the climate seemed to remain cold, but aridity increased. Period B (5.8–1.7 kyr BP) was characterised by frequent and sharp alternations between warm and cold conditions. Unstable conditions during this time are also registered in records from Lakes Baikal, Khubsugul and various other shallow lakes of the region. Optimal warm and wet conditions seemed to occur ca. 4 kyr BP. During Period A (the last 1.5 kyr) the diatom and chironomid records show evidence of cold conditions at 1.5–1 kyr BP, but the forest vegetation did not change significantly")
(ii) ice age
https://en.wikipedia.org/wiki/Ice_age#Major_ice_ages  ("Earth's climate alternates between ice ages and greenhouse periods, during which there are no glaciers on the planet [anywhere]"/ section 3 Major ice ages:
("The Quaternary Glaciation / Quaternary Ice Age started about 2.58 million years ago at the beginning of the Quaternary Period [up to the present] * * * The earth is currently in an interglacial, and the last glacial period ended about 10,000 years ago")
(iii) Holocene
https://en.wikipedia.org/wiki/Holocene  
("is the current geological epoch. It began approximately 11,650 cal years before present, after the last glacial period"/ section 1 Etymology)

choi

(2) Mammoth DNA sequenced.

Ewen Callaway, Million-Year-Old Mammoth Genomes Shatter Record for Oldest Ancient DNA. Nature, _: _ (Feb 17, 2021; in the News section of hard copy)  
https://www.nature.com/articles/d41586-021-00436-x

Quote:

"Genomic DNA extracted from a trio of tooth specimens excavated in the 1970s has identified a new kind of mammoth that gave rise to a later North American species [called Columbian mammoth]. The findings were published in Nature on 17 February.

"Ludovic Orlando [born in France; how he got that first name, I am clueless], an ancient-DNA specialist at the Centre for Anthropobiology and Genomics of Toulouse in France, who co-led a 2013 effort that sequenced the previous oldest ancient DNA — a genome from a 560,000-to-780,000-year-old horse leg bone.

"Love Dalén, an evolutionary geneticist at the Swedish Museum of Natural History (SMNH) in Stockholm, had been dallying with the idea of sequencing very old mammoth remains since he first encountered a collection of them, in 2007 [that is why a sectional heading in this article says 'Decadal dream']. The samples his team sequenced, one from an early woolly mammoth (Mammuthus primigenius) and two assigned to a precursor known as steppe mammoths (Mammuthus trogontherii), had been excavated by the [late] Russian palaeontologist Andrei Sher ['retrieved from [permafrost] sediments' without the rest of mammoth bones].

"thanks to advances in sequencing technology and bioinformatics, his team managed to obtain 49 million base pairs of nuclear DNA from the oldest sample, found near a village called Krestovka, and 884 million base pairs from another tooth, called Adycha. Analysis of the DNA suggested that the Krestovka sample was 1.65 million years old, and the Adycha sample around 1.3 million. The third sample, a 600,000-year-old woolly mammoth tooth dubbed Chukochya, produced nearly 3.7 billion base pairs of DNA, more than the length of its 3.1-billion-base-pair genome.

Note: Columbian mammoth
https://en.wikipedia.org/wiki/Columbian_mammoth
(map in table; 4 m (13 ft) at the shoulders and 10 t (22,000 lb) in weight; Columbian mammoth disappeared at the end of the Pleistocene around 11,500 years ago;  was first scientifically described in 1857 by [Scottish] naturalist Hugh Falconer, who named the species Elephas columbi after the explorer Christopher Columbus)