3 ms·

A golden age of ancient DNA science begins

45 points by diodorus 11y ago

gardano 11y ago
As a rank amateur, I have a question. Is the question of speciation a useful construct anymore? I mean, birds are dinosaurs and (some) dinosaurs were birds. There is Neanderthal and Denisovian DNA in Homo Sapiens. Is the definition of what is a species tantamount to the legendary medieval argument of how many angels can dance on the head of a pin? I'm not trying to be snarky. I'm curious as to the usefulness of the way we're approaching categorisation. Genuine, but ill-informed, question.
- danieltillett 11y ago
  Species is a complex concept which does not always fit into nice simple buckets. You might find ring species interesting [1]. 1. https://en.m.wikipedia.org/wiki/Ring_species https://en.m.wikipedia.org/wiki/Ring_species
  - gardano 11y ago
    Fascinating. Thanks!
tokenadult 11y ago
I'd appreciate comments from someone who follows this research about what John Hawks says about ancient DNA studies and their recent findings. I get the impression that he is reaching some different conclusions from the author whose essay was kindly submitted here. http://johnhawks.net/weblog/reviews/neandertals/neandertal_dna/neandertal-early-modern-gene-flow-kuhlwilm-2016.html http://johnhawks.net/weblog/reviews/neandertals/neandertal_d...
- danieltillett 11y ago
  Not really - they are just focusing on different aspects of the story. What I find most amazing is the author can present scientific evidence that Neanderthals were different species and the consequence of what this means is completely ignored.
r0muald 11y ago
Original article here: https://theconversation.com/a-golden-age-of-ancient-dna-science-begins-56582 https://theconversation.com/a-golden-age-of-ancient-dna-scie... with more than a few comments raising questions about the actual meaning of the x% figures given in this article.
noname123 11y ago
I attended a really good guest lecture by Dr.David Reich (with additional work also by Dr.Nick Patterson) on analyzing ancient DNA. "Massive migration from the [Anatolian] steppe is a source for Indo-European languages in Europe" I can't find the slides/video recording anywhere (it's a shame because it was the most accessible presentation on genetics I found to everyone). Dr.Reich didn't go into too much technical details during the lecture; the audience was to a bunch of undergrad and first year grad students interested in computational biology; and guest lecturers are PIs around the Boston area who are trying to recruit for students into their labs. However, he did hint some of analysis they did to construct the migration path came from the distribution of particular classes of metabolic genes for different diets; meaning, early human beings can be classified as farmers (grain-based diet), hunter-gatherers (raw meat) and nomadic people (consume more animal products, lactose); by collecting samples collected in Europe, carbon-dating them and constructing phylogeny tree (most percentage of shared single nucleotide polymorphism are classified as siblings, least likely amount of base mutations to the target offsprings are labeled as parents) amongst the samples and classifying them amongst these three diet-based cohorts and sample-collection sites, you can begin to construct a likely migratory path. Also Dr.Riech also made an interesting point that the reason why most ancient DNA research is done in Europe and not really in Africa which would seem more logical is because: most grants to do the work come from European scientific agencies who have mandates to fund their own anthropology and culture studies (an unintended "Eurocentric" side-affect of research grants). Here is the Nature article instead: http://www.nature.com/nature/journal/v522/n7555/abs/nature14317.html http://www.nature.com/nature/journal/v522/n7555/abs/nature14... Non-paywall version: http://arxiv.org/pdf/1502.02783.pdf http://arxiv.org/pdf/1502.02783.pdf
- danieltillett 11y ago
  One of the other reasons is DNA survives best at low temperature. Unfortunately there are not many places in Africa where the temperature is low enough to have DNA survive 10,000s of years.
amasad 11y ago
If Humans and Neanderthals are that far apart does it mean that higher intelligence evolved independently in multiple species? If Neanderthals had languages capabilities (which I think is debated) then that may mean that human-like intelligence is not all that rare that we think it is. What implications does this have on intelligence evolving somewhere else in the galaxy (if any)?

45 points by diodorus 11y ago

As a rank amateur, I have a question. Is the question of speciation a useful construct anymore? I mean, birds are dinosaurs and (some) dinosaurs were birds. There is Neanderthal and Denisovian DNA in Homo Sapiens. Is the definition of what is a species tantamount to the legendary medieval argument of how many angels can dance on the head of a pin? I'm not trying to be snarky. I'm curious as to the usefulness of the way we're approaching categorisation. Genuine, but ill-informed, question.

danieltillett 11y ago
Species is a complex concept which does not always fit into nice simple buckets. You might find ring species interesting [1]. 1. https://en.m.wikipedia.org/wiki/Ring_species https://en.m.wikipedia.org/wiki/Ring_species
- gardano 11y ago
  Fascinating. Thanks!

tokenadult 11y ago

I'd appreciate comments from someone who follows this research about what John Hawks says about ancient DNA studies and their recent findings. I get the impression that he is reaching some different conclusions from the author whose essay was kindly submitted here. http://johnhawks.net/weblog/reviews/neandertals/neandertal_dna/neandertal-early-modern-gene-flow-kuhlwilm-2016.html http://johnhawks.net/weblog/reviews/neandertals/neandertal_d...

danieltillett 11y ago
Not really - they are just focusing on different aspects of the story. What I find most amazing is the author can present scientific evidence that Neanderthals were different species and the consequence of what this means is completely ignored.

r0muald 11y ago

Original article here: https://theconversation.com/a-golden-age-of-ancient-dna-science-begins-56582 https://theconversation.com/a-golden-age-of-ancient-dna-scie... with more than a few comments raising questions about the actual meaning of the x% figures given in this article.

noname123 11y ago

I attended a really good guest lecture by Dr.David Reich (with additional work also by Dr.Nick Patterson) on analyzing ancient DNA. "Massive migration from the [Anatolian] steppe is a source for Indo-European languages in Europe" I can't find the slides/video recording anywhere (it's a shame because it was the most accessible presentation on genetics I found to everyone). Dr.Reich didn't go into too much technical details during the lecture; the audience was to a bunch of undergrad and first year grad students interested in computational biology; and guest lecturers are PIs around the Boston area who are trying to recruit for students into their labs. However, he did hint some of analysis they did to construct the migration path came from the distribution of particular classes of metabolic genes for different diets; meaning, early human beings can be classified as farmers (grain-based diet), hunter-gatherers (raw meat) and nomadic people (consume more animal products, lactose); by collecting samples collected in Europe, carbon-dating them and constructing phylogeny tree (most percentage of shared single nucleotide polymorphism are classified as siblings, least likely amount of base mutations to the target offsprings are labeled as parents) amongst the samples and classifying them amongst these three diet-based cohorts and sample-collection sites, you can begin to construct a likely migratory path. Also Dr.Riech also made an interesting point that the reason why most ancient DNA research is done in Europe and not really in Africa which would seem more logical is because: most grants to do the work come from European scientific agencies who have mandates to fund their own anthropology and culture studies (an unintended "Eurocentric" side-affect of research grants). Here is the Nature article instead: http://www.nature.com/nature/journal/v522/n7555/abs/nature14317.html http://www.nature.com/nature/journal/v522/n7555/abs/nature14... Non-paywall version: http://arxiv.org/pdf/1502.02783.pdf http://arxiv.org/pdf/1502.02783.pdf

danieltillett 11y ago
One of the other reasons is DNA survives best at low temperature. Unfortunately there are not many places in Africa where the temperature is low enough to have DNA survive 10,000s of years.

amasad 11y ago

If Humans and Neanderthals are that far apart does it mean that higher intelligence evolved independently in multiple species? If Neanderthals had languages capabilities (which I think is debated) then that may mean that human-like intelligence is not all that rare that we think it is. What implications does this have on intelligence evolving somewhere else in the galaxy (if any)?