looking into the possibility of Indian groups receiving Steppe related ancestry after 1500 BC

From the Supplementary Materials for The formation of human populations in South and Central Asia by Narasimhan et al. 2019:

A claim made in The formation of human populations in South and Central Asia by Narasimhan et al. 2019 and the Steppe theorists is that the Steppe related ancestry present in the Indian people entered within 2000-1500 BC. and this is based on groups like Ksirov_H_Kushan and Steppe_LBA that have high admixture from East Asian related groups.

however Genetic continuity of Indo-Iranian speakers since the Iron Age in southern Central Asia by Vignon et al. 2022 has some interesting information.

from aat7487_tables1-5.xlsx of Narasimhan et al. 2019

they model Turkmenistan_IA which is dated to around 912-799 calBCE without East Asian admixture and also claim most of the East Asian admixture in the Central Steppe only arrived towards the end of the Iron Age however Steppe theorists would like to respond by saying that the sample has high BMAC related ancestry which is at around 43% people like @agenetics1 would like to argue that a Turkmenistan_IA like population ended up mixing with an AASI heavy source from an IVC source which has issues like assuming high Amounts of AASI admixture in the Indus_Periphery.

however in Genetic history of Scythia by Andreeva et al. 2025 we see some interesting information regarding both the presence of BMAC related ancestry and East Asian related ancestry. 

From Tables S1 to S31, S34 to S46, S48, S49, S52, S53, S55, and S59 to S64 of Genetic history of Scythia by Andreeva et al. 2025:

Sample ID DS70 would have around 90-95% of its ancestry from a Sintashta like source, some 3-7% East Asian admixture? with its BMAC being Related ancestry being 0% and this seems to be dated to middle-third quarter of the 4th century BC.

sample ID AS7 would have around 72.9% Sintashta related ancestry + around 22% BMAC related ancestry which is much lesser than the percentage present in Turkmenistan_IA with around 3-7% of its ancestry coming from an East Asian source and this sample seems to be dated to the second half of the 2nd century - the beginning of the 1st century BC.

sample ID DS64 would have around 67% Steppe_MLBA like ancestry with its remaining ancestry coming from the individuals of the BMAC which is also lesser than the one present in Turkmenistan_IA without admixture from an East Asian like source and this sample is dated to the middle of 4th century BC.

as we can see from the data above even as far as around 400 BC we can find individuals without both BMAC and East Asian admixture 

the steppe theorist could however still argue on the Indians not being modelled using BMAC related ancestry according to Narasimhan et al. 2019

Ancient genomes from eastern Kazakhstan reveal dynamic genetic legacy of Inner Eurasian hunter-gatherers by Gill et al. 2025 is yet another interesting study to look into with regards to the possibility of a Steppe_MLBA contributing to the Indian genome after 1500 BC but at the same time prior to 1000-900 BC.

 

the main cluster of Koken_MLBA is Central_Steppe_MLBA like. sample ID ICA19B seem to belongs to the main cluster of the Koken_MLBA individuals who are Sintashta_MLBA like with 6-8% WSHG like ancestry.

From Data S1 to S8 of Ancient genomes from eastern Kazakhstan reveal dynamic genetic legacy of Inner Eurasian hunter-gatherers by Gill et al. 2025:

other than sample ID ICA19B all of the other samples are pre 1500 BC but sample ID ICA19B still falls under the main cluster the sample is dated from somewhere around 1507-1407 BC.

this sample most likely existed after 1500 BC but is still not too late.

however in the Supplementary Materials for The formation of human populations in South and Central Asia by Narasimhan et al. 2019 we see samples that exist much later that would also fall under the main Central_Steppe_MLBA cluster.

An individual from Taldysay seems to fall under the main Central_Steppe_MLBA cluster and this individual is dated to around 1379-1196 calBCE which is much far away from 1500 BC.

2 individuals from Kashkarchi also seem to fall under the main Central_Steppe_MLBA cluster and these samples are dated to around 1200-1000 BCE.

two samples dated to around 1400-900 BCE from Shoendykol_MLBA_Fedorovo also seem to fall under the main Central_Steppe_MLBA cluster these individuals also have a similar genetic profile to an individual that is dated to around 1500 BC from the same culture.

 

Sample ID I11542 from Guruldek_LBA also seems to fall under the main Western_Steppe_MLBA cluster and this sample is dated from somewhere around 1500-1100 BC (probably somewhere close to 1300 BC?). the sample does not even seem to carry admixture from a Central_Steppe_EMBA like source unlike Central_Steppe_MLBA.

from aat7487_tables1-5.xlsx of Narasimhan et al. 2019

A sample taken from Allentoft et al. 2015 also seems to fall under the main Central_Steppe_MLBA cluster and is also dated from somewhere around 1446-1298 calBCE.

this sample is once again later than 1500 BC and is also later compared to the sample from Koken_MLBA .

so we can see Genetic profiles of individuals who fall under the main cluster of Central_Steppe_MLBA even as far as around 1100 BC and steppe groups with a similar profile around this time most likely contributed to the Indian genome with the Indo-Aryans existing prior to their admixture with Steppe groups and receiving their language through an Indus_Periphery_Pool like source.