Is ISIS committing genocide against the Yazidis?

Question

From Fact Checks of the Eighth Republican Debate, on the New York Times website:

Senator Marco Rubio said President Obama had played down the threat of the Islamic State, which practices genocide.

An exaggeration.

Senator Marco Rubio's charge that President Obama has played down the threat of the Islamic State ends up inflating the threat from the group. While it is true that the Islamic State has targeted Christians and Yazidis, there is no evidence that it has carried out genocide against those groups.

— Mark Landler

I was under the impression that no-one's disputing that ISIS is taking Yazidis as sex slaves and forcibly converting them to Islam, which easily qualifies as genocide. The only thing I don't know about is whether ISIS is systematically killing Yazidis and/or a subset of Yazidis (what some people may refer to with genocide).

The New York Times has form for failing to state that a genocide is going on.

Is there no evidence that ISIS has committed genocide against the Yazidis?

Update The New York Times has since issued a correction and updated its statement:

Senator Marco Rubio said President Obama had played down the threat of the Islamic State, which practices "genocide against Christians and Yazidis and others in the region."

An exaggeration.

Senator Marco Rubio's charge that President Obama has played down the threat of the Islamic State ends up inflating the threat from the group. Several organizations have concluded that the Islamic State targeted Yazidis with a campaign of genocide, but there is no evidence that it so targeted Christians.

Correction: An earlier version of this fact check imprecisely described the Islamic State's record of treatment of religious minorities in areas where it has operated. Several organizations have concluded there is evidence the group carried out a campaign of genocide against the Yazidis, as Mr. Rubio asserted; it was not accurate to say that there is no evidence to support that claim. The statement was made in a Republican presidential debate in January, and the matter was recently brought to The New York Times's attention by several readers.

— Mark Landler

Answer 1

At least 5,000 Yazidi civilians have been murdered.

Quoting from the Wikipedia article:

Classification as Genocide

The persecution of the Yazidi people has been viewed as qualifying as genocide by groups such as the Office of the United Nations High Commissioner for Human Rights in a March 2015 report. The organization cited the numerous atrocities such as forced religious conversion and sexual slavery as being parts of an overall malicious campaign.[10][98] Multiple individual human rights activists such as Nazand Begikhani and Dr. Widad Akrawihave also advocated for this view.[51][99] The term itself first arose in 1944 as the creation of a Polish-Jewish lawyer named Raphael Lemkin, who himself defined the term as reflecting "a coordinated plan of different actions aiming at the destruction of essential foundations of the life of national groups, with the aim of annihilating the groups themselves."[100]