Tweets from ASHG 2015 can be found here. By the way, I know that today at 5.15pm, Baltimore time, Razib will be at Iosif Lazaridis' ASHG talk on the genetic affinities of Neolithic Anatolians. If his tweets don't appear there, you'll find them here.
Update: Here are some of those tweets from Razib...
@iosif_lazaridis revision of paper @mathiesoniain with more ancestry stuff on biorxiv soon [in fact, see here]
@iosif_lazaridis [Neolithic Anatolian] mtDNA look familiar to EEF. Y mostly G2a2. also J2 H and I at low frequency. C1 too
@iosif_lazaridis anatolian neolithic close to EEF on pca. but EEF shifted toward WHG #ASHG15
@iosif_lazaridis anatolian neolithic different from modern anatolian and se europe populations.
@iosif_lazaridis eurasian steppe, population transect done. 5,500 to 1,200 BC. author told me some R1a1a possibile stuff here yesterday
@iosif_lazaridis indo-european steppe = EHG + near eastern. new data eneolithic samara. 75% EHG ancestry. 25% "armenian" 5,200 to 4,000 BCE
@iosif_lazaridis poltavka people 3000 to 2200 BC basically like yamnaya. 50% EHG and 50% armenian-like. then srubnaya different.
@iosif_lazaridis srubnaya 2/3 yamnaya 1/3 middle neolithic european
@iosif_lazaridis yamnaya/poltavka went from R1b to R1a in the srubnaya period. z93 group found on bronze age steppe samara (s asian R1a)
@iosif_lazaridis there was back migration of EEF to the steppe after the initial yamnaya migration.