Domestication of Dogs

DNA Unit 2 Lecture 7 Domestication of Dogs: how much human complex evolution patterns & interbreeding are like dogs which created vast domestication which completely altered the dog genome through selective genome even though there were relatively little changes, which gives us a warning of how small changes can have a large effect ●​ Dog domestication existed thousands of years ago and have similarities of bark, tamed, curled tails, mottled coats, floppy ears, wag (wolves have none of these) ●​ Made them tame to work as protectors and companions ●​ Tree of Canids/Canines (wolves, foxes, related) dogs descended from grey wolf ●​ Wide diversification of dogs, most European gods are a small subset from Asia ○​ Patterns of divergence like human history, similarly, related to each other Evolution of Coat Color in North American Wolves: complicated diversity patterns happen frequently. Some Young wolves have black color (exception from black color being the domesticate) then become gray when get older ●​ Traced by pedigrees, allele for black coats was introgressed into wolves from domestic dogs ●​ Wolves with black coats contains a “haplotype” (SNPs at several linked sites) not seen in other wolves but found in domestic dogs ○​ Shows the historical contingency of gene flow, migration, adaptation ○​ Pattern of divergence to introgression in humans ●​ Know that lots of genes are involved in complex traits, but don’t know much about how they interact with each other Belyaev's Farm Fox Experiment: Domestication of foxes for coat industry: selected for foxes that can be tamed by seeing if they attacked or not. Selected for flight distance (how close can get before turn and run but reacted kindly). The new generations reformed in personality/color/fur/ear appearance and not afraid of people that relate to dogs ●​ Selecting for tame along could cause a cascade of other changes ○​ Set of genetics of the entire makeup of the animal that produce a characteristic response due to one system affecting another ●​ Domestication of dog characteristic (wag, ears): emergent property of the dog that says something abt the genome when selecting for tameness ●​ Like Human Genes: Select for one trait can influence others, don’t know much about it so more studies, can’t select one trait/gene as all are interconnected ●​ Connection to CRISPR: can’t modify one gene without affecting something else, so can’t just change one gene without knowing the effects of it (much unknown) Extinction: events where massive numbers of species die off; coincide with geological eras due to fossils organisms that define this ●​ 5 Mass Extinction: animals disappear from fossil record and others appear where the major classification of life is defined by the fossil record and organisms alive th The Anthropocene: First Human mediated 6 Mass Extinction, many species endangered ●​ Extinction of Pleistocene Megafauna ●​ Oldest DNA extracted by 1.2-million-year Mammoth tooth, Ancient DNA that was well preserved and was sequenced. Similar method to learn about Neantherals, colonization and diversification. Aligned the genomes of Mammoth and Elephants (28 chromosomes) to see similarities/differences and 3% was different ○​ Ex. EGFR develops hair follicles, in humans, but slightly different for mammoths to have thicker woolly coat. But also, could be from a cold environment so selected for thicker coat De-Extinction: take extinct and revive/rescue it, could reverse The Anthropocene ●​ If the environment changed, why would we want to bring it back? ○​ Diversify the organisms we have, especially cuz humans drove them extinct ○​ Could help the environment; ecosystem restoration ■​ Ex. Keystone Species that affect basic features of the landscape ■​ Ex. Mammoth kept Tundra as grassland, Passenger Pigeon decreased fire frequency in forests, bats, deer, snakes