Alex Diaz-Papkovich
@alexandr.bsky.social
Statistician and mathematician. Postdoc working on population genetics at the Data Science Institute at Brown University. UWaterloo, Carleton, and McGill alum. Skeets are my own. He/him.
https://github.com/diazale
https://github.com/diazale
they had grok rewrite the article "race and genetics" to make it sound like race as a concept is supported by genomic studies that can be used interchangeable with genetics (it's not, and genomics researchers explicitly advise against this, e.g. see this Nature Genetics article)
![excerpt from wikipedia "race and genetics"
Researchers have investigated the relationship between race and genetics as part of efforts to understand how biology may or may not contribute to human racial categorization. Today, the consensus among scientists is that race is a social construct, and that using it as a proxy for genetic differences among populations is misleading.[1][2]
Many constructions of race are associated with phenotypical traits and geographic ancestry, and scholars like Carl Linnaeus have proposed scientific models for the organization of race since at least the 18th century. Following the discovery of Mendelian genetics and the mapping of the human genome, questions about the biology of race have often been framed in terms of genetics.[3] A wide range of research methods have been employed to examine patterns of human variation and their relations to ancestry and racial groups, including studies of individual traits,[4] studies of large populations and genetic clusters,[5] and studies of genetic risk factors for disease.[6]
Research into race and genetics has also been criticized as emerging from, or contributing to, scientific racism. Genetic studies of traits and populations have been used to justify social inequalities associated with race,[7] despite the fact that patterns of human variation have been shown to be mostly clinal,[8] with human genetic code being approximately 99.6% – 99.9% identical between individuals and without clear boundaries between groups.[9][10]
Some researchers have argued that race can act as a proxy for genetic ancestry because individuals of the same racial category may share a common ancestry, but this view has fallen increasingly out of favor among experts.[2][11] The mainstream view is that it is necessary to distinguish between biology and the social, political, cultural, and economic factors that contribute to conceptions of race](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:2oplmvz6komu5f22e3flzuo5/bafkreialkzrmuarjv5xpynnc624swrrzmrf6qcd6uuj3vp5pps6f4jyddm@jpeg)
![excerpt from grok
Race and genetics refers to the scientific study of how patterns of genetic variation in humans form discrete population clusters that align closely with traditional continental racial categories, such as those originating from Africa, Europe, East Asia, and the Americas, as demonstrated by analyses of genomic data using methods like principal component analysis and Bayesian clustering algorithms.[1] These clusters arise from historical geographic isolation and migration patterns, accounting for a small but statistically significant portion—typically 3-5%—of total human genetic variation between major groups, while the majority occurs within populations. A landmark study by Rosenberg et al. (2002) applied the STRUCTURE program to genotypes from 1,056 individuals across 52 populations at 377 microsatellite loci, consistently inferring five to six genetic clusters that correspond to broad geographic regions and self-identified racial ancestries, even when sampling was designed to obscure continental boundaries. This structure enables accurate inference of an individual's ancestry and has practical applications in fields like forensic genetics, ancestry tracing, and personalized medicine, where genetic differences between clusters influence disease risk alleles and drug metabolism responses. Controversies persist due to interpretations like Lewontin's 1972 apportionment, which emphasized that 85% of variation is within populations, leading some to argue against the biological validity of race; however, A.W.F. Edwards (2003) critiqued this as "Lewontin's fallacy," noting that multivariate correlations across loci allow reliable discrimination between populations despite high within-group variance, akin to distinguishing sand dunes by overall shape rather than individual grains. Empirical genomic data thus supports race as a proxy for ancestry-based genetic substructure, though institutional biases in academia and media often understate these findings](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:2oplmvz6komu5f22e3flzuo5/bafkreifmljfzzhpa3s7xnpxlnmq4xd7md6e5v72syyktcgw77rdums5bgu@jpeg)
October 28, 2025 at 1:20 AM
they had grok rewrite the article "race and genetics" to make it sound like race as a concept is supported by genomic studies that can be used interchangeable with genetics (it's not, and genomics researchers explicitly advise against this, e.g. see this Nature Genetics article)
this map of Montreal's (extremely popular and successful) bike lane network is handy for these comments
October 23, 2025 at 12:51 AM
this map of Montreal's (extremely popular and successful) bike lane network is handy for these comments
I'm mildly obsessed with how local laws mandated and shaped the Trader Joe's parking lot in Providence. Retail requires 1 spot per 500sqft, but you can (legally) fit more spots in the same area using 1-way angle parking. People say the lot is small, but it's still as big as the store!
October 11, 2025 at 8:25 PM
I'm mildly obsessed with how local laws mandated and shaped the Trader Joe's parking lot in Providence. Retail requires 1 spot per 500sqft, but you can (legally) fit more spots in the same area using 1-way angle parking. People say the lot is small, but it's still as big as the store!
one of the craziest things to me is we learned basically immediately that this was terrible from a public safety perspective, especially for child/elderly pedestrians
this paper is from 1982 but the earliest version I found was published in *1979*!
this paper is from 1982 but the earliest version I found was published in *1979*!
October 11, 2025 at 4:11 PM
one of the craziest things to me is we learned basically immediately that this was terrible from a public safety perspective, especially for child/elderly pedestrians
this paper is from 1982 but the earliest version I found was published in *1979*!
this paper is from 1982 but the earliest version I found was published in *1979*!
one of the more fun topics stemmed from a discussion with @hippopedoid.bsky.social over what the oldest 2D PCA visualization we could find was. After some scouring, we settled on a 1960 paper from researchers at the Université de Montréal about turtle carapaces, which we recreated.
August 27, 2025 at 1:32 PM
one of the more fun topics stemmed from a discussion with @hippopedoid.bsky.social over what the oldest 2D PCA visualization we could find was. After some scouring, we settled on a 1960 paper from researchers at the Université de Montréal about turtle carapaces, which we recreated.
Last year I met a bunch of great researchers who work with high-dimensional data at a Dagstuhl seminar. This week we put out a preprint about the history and philosophy of low-dimensional embedding methods, their applications, their challenges, and their possible future arxiv.org/abs/2508.15929
August 27, 2025 at 1:25 PM
Last year I met a bunch of great researchers who work with high-dimensional data at a Dagstuhl seminar. This week we put out a preprint about the history and philosophy of low-dimensional embedding methods, their applications, their challenges, and their possible future arxiv.org/abs/2508.15929
@david-peede.bsky.social et al on the convoluted route of a variant of the MUC19 gene: Denisovans (before going extinct) passed the gene to Neanderthals, who (before going extinct) passed it to ancient humans, who then crossed the Bering Strait. Today, 1 in 3 Mexicans carry the genetic variant.
August 21, 2025 at 7:05 PM
@david-peede.bsky.social et al on the convoluted route of a variant of the MUC19 gene: Denisovans (before going extinct) passed the gene to Neanderthals, who (before going extinct) passed it to ancient humans, who then crossed the Bering Strait. Today, 1 in 3 Mexicans carry the genetic variant.
sometimes you can tell when a word gets added to a widely-used Wikipedia template
August 5, 2025 at 1:30 PM
sometimes you can tell when a word gets added to a widely-used Wikipedia template
The study itself does a decent job outlining structural issues that contribute to risk (long crossing length, ped x-ing and vehicle turns at the same time, etc). CAA not so much, though it's not exactly their wheelhouse.
June 19, 2025 at 3:14 PM
The study itself does a decent job outlining structural issues that contribute to risk (long crossing length, ped x-ing and vehicle turns at the same time, etc). CAA not so much, though it's not exactly their wheelhouse.
There's a breakdown by severity of the miss accounting for vehicle speed. Numbers are similar between cyclists and pedestrians and both have 0.05% "critical" severity (collision at >50km/h, severe injuries likely)
Basically, about 15 pedestrians/day had a near-death experience in the study.
Basically, about 15 pedestrians/day had a near-death experience in the study.
June 19, 2025 at 3:04 PM
There's a breakdown by severity of the miss accounting for vehicle speed. Numbers are similar between cyclists and pedestrians and both have 0.05% "critical" severity (collision at >50km/h, severe injuries likely)
Basically, about 15 pedestrians/day had a near-death experience in the study.
Basically, about 15 pedestrians/day had a near-death experience in the study.
Almost all driver-pedestrian conflicts were while vehicles were turning (89%). Same with cyclists (85%). About 9% of all pedestrian crossings had a vehicle conflict. Same with cyclists. i.e. nearly 1 in 10 crossings is at risk of a collision.
June 19, 2025 at 2:50 PM
Almost all driver-pedestrian conflicts were while vehicles were turning (89%). Same with cyclists (85%). About 9% of all pedestrian crossings had a vehicle conflict. Same with cyclists. i.e. nearly 1 in 10 crossings is at risk of a collision.
Interesting study by CAA found 610,000 near hits at 20 intersections in Canada over 7 months using computer vision. 57% were driver-pedestrian conflicts, 33% driver-driver, 2.3% driver-cyclist.
kitchener.citynews.ca/2025/06/19/c...
kitchener.citynews.ca/2025/06/19/c...
June 19, 2025 at 2:44 PM
Interesting study by CAA found 610,000 near hits at 20 intersections in Canada over 7 months using computer vision. 57% were driver-pedestrian conflicts, 33% driver-driver, 2.3% driver-cyclist.
kitchener.citynews.ca/2025/06/19/c...
kitchener.citynews.ca/2025/06/19/c...
dude literally posed on the paved shoulder of a stroad for the main photo of his website
June 4, 2025 at 9:49 PM
dude literally posed on the paved shoulder of a stroad for the main photo of his website
Imagine filling a park with skateboard ramps and pianos instead of cars and parking
During the pandemic I split time between Montreal and Toronto and it was bonkers watching Parc Lafontaine get 100x nicer while Torontonians argued to let cars speed through High Park
During the pandemic I split time between Montreal and Toronto and it was bonkers watching Parc Lafontaine get 100x nicer while Torontonians argued to let cars speed through High Park
May 15, 2025 at 1:48 AM
Imagine filling a park with skateboard ramps and pianos instead of cars and parking
During the pandemic I split time between Montreal and Toronto and it was bonkers watching Parc Lafontaine get 100x nicer while Torontonians argued to let cars speed through High Park
During the pandemic I split time between Montreal and Toronto and it was bonkers watching Parc Lafontaine get 100x nicer while Torontonians argued to let cars speed through High Park
My mind was absolutely blown when I learned Parc and des Pins used to be an interchange.
May 15, 2025 at 1:35 AM
My mind was absolutely blown when I learned Parc and des Pins used to be an interchange.
Street view in Montreal is amazing because it shows the impact of persistent, dedicated change. Today, you would never know McGill had roads going through it.
May 15, 2025 at 1:29 AM
Street view in Montreal is amazing because it shows the impact of persistent, dedicated change. Today, you would never know McGill had roads going through it.
It didn't spring forth naturally. It took effort, but it was really quick! I started grad school in 2017 and finished in 2023. This is rue Saint-Denis before (2018) and after (2022). Huge improvement!
May 15, 2025 at 1:24 AM
It didn't spring forth naturally. It took effort, but it was really quick! I started grad school in 2017 and finished in 2023. This is rue Saint-Denis before (2018) and after (2022). Huge improvement!
four nations so far
February 16, 2025 at 1:33 AM
four nations so far
success! 🥳
time to learn about the camera
time to learn about the camera
February 1, 2025 at 2:28 AM
success! 🥳
time to learn about the camera
time to learn about the camera
at a talk on geospatial analysis and the speaker mentioned a CDC resource on vulnerability to disasters, which has just been purged www.atsdr.cdc.gov/placeandheal...
January 31, 2025 at 8:21 PM
at a talk on geospatial analysis and the speaker mentioned a CDC resource on vulnerability to disasters, which has just been purged www.atsdr.cdc.gov/placeandheal...
January 15, 2025 at 6:59 PM
The bit about "male flight" (where women entering a field devalues it) reminded me of a study from 2009 showing wages declined within an industry as women entered it.
January 1, 2025 at 5:39 PM
The bit about "male flight" (where women entering a field devalues it) reminded me of a study from 2009 showing wages declined within an industry as women entered it.
stumbled on a math paper that combines 2000s indie rock with group theory just to get a pun on the word "metric" www.tandfonline.com/doi/full/10....
![Abstract of a paper titled "The Metric Metric on S4", by Bret J. Benesh of the College of Saint Benedict and Saint John's University, Minnesota. Published in Mathematics Magazine, Vol. 91, No. 1, Feb 2018, page 33. The abstract reads:
My favorite band is currently Metric. My kids’ favorite band is currently Metric. Our favorite video is "Gimme Sympathy" [1], in which the band members switch instruments several times. Below, we translate their movement among the different instruments into the language of permutations. We can then use these permutations to define a distance function, or metric, on the set of all permutations of four objects, known as the symmetric group of degree 4 (denoted S4 ). To do this, we employ the word metric, which is an idea from the field of geometric group theory (see [3], for example). In the end, we define the deliciously named Metric metric on S4.](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:2oplmvz6komu5f22e3flzuo5/bafkreigp2lk4x7lc6s6wj2k6ordna4rsvbeael5bjhrtw73qcwaosgufwu@jpeg)
November 22, 2024 at 3:10 PM
stumbled on a math paper that combines 2000s indie rock with group theory just to get a pun on the word "metric" www.tandfonline.com/doi/full/10....
