The TalkOrigins Archive has two articles (here and here) on observed instances of speciation. Now a recent PNAS paper describes speciation in Aspidoscelis, a genus of whiptail lizards. The paper is titled “Laboratory synthesis of an independently reproducing vertebrate species.” From the abstract:
Here we report the generation of four self-sustaining clonal lineages of a tetraploid species resulting from fertilization of triploid oocytes from a parthenogenetic Aspidoscelis exsanguis with haploid sperm from Aspidoscelis inornata. Molecular and cytological analysis confirmed the genetic identity of the hybrids and revealed that the females retain the capability of parthenogenetic reproduction characteristic of their triploid mothers. The tetraploid females have established self-perpetuating clonal lineages which are now in the third generation.
Read more at Nobel Intent, to which we tip our hat.