PIE spread

 An interesting map from the following paper.

https://www.cambridge.org/core/journals/proceedings-of-the-prehistoric-society/article/abs/forgotten-child-of-the-wider-corded-ware-family-russian-fatyanovo-culture-in-context/6309A60F638130BF6F7FD96135AA1B37#

There's one exception I'd make to the bottom map, though. It seems most possible that Yamnaya originated in the Western steppe, not the eastern steppe. The genetic evidence, according to Eurogenes, seems to suggest this, although there are other hints that it may have started in the east, as an outgrowth of Repin and Khvalynsk. Davidski suggests that post-Sredni Stog rolled over Khvalynsk, and that genetics can prove it, to create Yamnaya, and that early Corded Ware was genetically identical to Yamnaya. Later Corded Ware cultures picked up more admixture from native European hunter-gatherer and farmer ancestries.

In any case, the map doesn't feature time depth, though. Or rather, the second one adds some time depth. Keep in mind that Fatyanovo-Balanovo and Abashevo coexisted with the more westerly Corded Ware, and is usually considered a farther eastern extension of them. Sintashta has roots in Abashevo, but is considered a separate development. Andronovo is generally considered the eastern steppe explosion of Sintashta into territory that used to be the non-Indo-European Botai-Tersek culture earlier. Although granted, the Kazakhstan archaeological picture is a bit hazy because much more fieldwork is required.