There are a few pages of Spencer Wells book, "Deep Ancestry, Inside the Genographic Project," that include information about the mtDNA Haplogroup T2b. Pages 71-73 and page 101. A quote in Fig. 5, states "Frequency distribution of five major European mitochondrial haplogroups: H, K, T, U and V. These pre-Neolithic lineages all arose in or around the Middle East between 50,000 and 30,000 years ago before making their way into Western Europe."
I don't know much about the Haplogroups of WikiTree members.