Thierry Grange

It is a pleasure to work with Stephane! Great position in Paris 👇

#PopGen #StatGen #AncientDNA #GWAS #ARGs #Postdoc

A very promising starting lab, a friendly PI, an opportunity for a career.

Administrative retirement, but not yet ready to give up science. We will continue on another floor. No chance that we purify nuclei anymore, though. Enjoy it.

Wrong link

Do I understand properly that you imputed only variants that are common today, and thus none of the specific variants that are used to infer that they didn't contribute ancestry to the subsequent waves?

How come imputation with modern genomes can be accurate if Ranis and Zlaty Kun have not contributed ancestry to later arriving anatomically modern humans as claimed in the paper? If they don't share their specific ancestry with modern humans, imputation should not work at these specific positions.

📣Exposition AGRIPOP

📆 Jusqu'au 16 décembre 2024
📍 Hall A des Grands Moulins / Université Paris Cité

Il reste encore 1 semaine pour visiter AGRIPOP, une exposition mise en place par l'équipe "Épigénome & Paléogénome” (@thierrygrange.bsky.social) de l’@ijmonod.bsky.social !

🔗https://urls.fr/HPX142

An explanation for the sister repulsion phenomenon in Patterson's f-statistics Abstract. Patterson's f-statistics are among the most heavily utilized tools for analyzing genome-wide allele frequency data for demographic inference. Bey

🧪 #aDNA 🧬🖥️ A very interesting paper by Gözde Atağ, Mehmet Somel and colleagues of METU showing how f-statistics results can be confounded by low-level admixture from an unaccounted source. academic.oup.com/genetics/art...

I started a scientific discussion with another colleague who posted this paper where I argued that these creations of new paleospecies names for a subset of bones were not helping in a better understanding of human evolution, on the contrary. He preferred to block me than being contradicted. 🥲

If you can reformulate your question after reading them, if you still want to discuss this matter. Thanks.

I will answer publicly later today. Meanwhile, you can find the articles I mentioned here filesender.renater.fr?s=download&t...

🏺🧪 #aDNA
#Evolution
🧬🖥️ Reposting a scientific exchange with a colleague who proposes paleospecies and who is not willing to be challenged about what he is doing and prefers to block posts to silence the disagreements.

Defining categories can be useful to structure our thinking, but categories can be counterproductive when they hide the relationships that exist between different parts. I am concerned that many paleospecies fall into the counterproductive category.

They do not result from a bona fide biological selection. The risk is just very high that phenotypic diversity within a metapopulation is overinterpreted as defining features of a biological species.

Paleospecies are resulting from a different purely random process: the chances of a favorable set of taphonomic conditions favoring preservation and the serendipitous discovery of the bones.

Biological species result from the subsampling through time of the past biodiversity and the various bushy branches of metapopulations. This subsampling was involving both selection and chance but has been validated by time and survival.

I agree with your point and this is exactly why I am not convinced by many paleospecies, not talking about the very concept of paleospecies.

There were good biological reasons that Svante Paabo did not name the Denisovans as Homo denisovans. I find it useful to integrate multiple perspectives. Genomics can, and should, in my view, widen the perspective of Paleoanthropology.

I don't see that separating Homo longi and Denisovians into different species and renaming the Denisovians Homo juliensis is lumping and is clarifying the landscape.

I read the paper just before posting anything. I see that they are oversplitting and even adding a new species, and I think that it had more confusion than clarity.

... you can better describe it as a bushy evolution within (a) structured metapopulation(s) showing local phenotypic variability, sometime adaptative. Putting a few rigid boxes (species) into this complex landscape based on a few bones biases our thinking process and hides the full picture.

The problem I see with the species concept is that it was used since the 18th century to describe highly divergent lineages after all the intermediate branches were removed through random evolution and sometimes selection. When you study the evolutionary process over a short (1 My) distance...

🏺🧪 #aDNA #Evolution 🧬🖥️ Just reread this excellent paper from @elliescery.bsky.social about the Ragsdale paper discussing the differences between species and stems in human evolution. www.nature.com/articles/s41...

A weakly structured stem for human origins in Africa - Nature An analysis of models of human populations in Africa, using some newly sequenced genomes, finds that human origins in the continent can best be described by a weakly structured stem model.

Putting boxes (species names) around subparts of a bushy evolutionary tree hampers our understanding of evolution. See www.nature.com/articles/s41... for a better understanding of the complexity of human evolution integrating multiple genomes rather than relying just on isolated individual bones.

"The return of the splitters" aka "The splitters strike back"!

Thank you, Pedro, for your involvement in solving this issue.

Thanks. I am glad you liked it.

What should I do to post this in the #aDNA list?

Some of the icons did not allow my post to reach the places I targeted 🏺🧪 and #aDNA