Final answer:
Homo sapiens, appearing around 200,000 years ago, are known for their capacity for abstract thought, dating back at least 100,000 years.
Step-by-step explanation:
The hominin capable of abstract thought and known to date back as far as 100,000 years is Homo sapiens. Early members of the Homo sapiens species exhibited physical characteristics similar to modern humans, with a prominent capacity for abstract reasoning, technological innovation, and complex language. By around 200,000 years ago, Homo sapiens with our physical traits were already present, and their average brain size was about 1,400 cubic centimeters, indicating a strong capability for abstract cognitive processes.