Final answer:
Homo floresiensis lived approximately 100,000 to 60,000 years ago on Flores Island and their small brain size did not affect their intelligence, as evidenced by their use of tools and fire. Their unique characteristics are likely a result of genetic drift, often attributed to island dwarfism.
Step-by-step explanation:
The specimen in question is Homo floresiensis, an extinct species of archaic humans that lived on Flores Island in Indonesia. Regarding the choices provided, Homo floresiensis:
- Lived approximately 100,000 to 60,000 years ago, not around 20,000 years before present (yBP).
- The small body size of H. floresiensis does not seem to be a result of Allen's Rule, which is about adaptations to cold climates. Instead, their size is often attributed to island dwarfism, a form of genetic drift.
- Their small brain size of about 380 cc did not necessarily imply reduced cognitive abilities. Evidence shows they made tools and used fire, similar to what has been observed with Homo erectus.
- Their unique characteristics and size may indeed be a result of genetic drift, particularly within the phenomenon known as 'island dwarfism'.
In conclusion, while other Homo species such as Homo luzonensis presented a mix of traits, Homo floresiensis stood out due to its size and brain capacity relative to its body proportions and evident intelligence as per archaeological findings. The features H. floresiensis had, like flat and relatively long feet and more mobility in the elbow joint, suggest their bipedalism was different from modern humans, indicating a unique adaptation to their environment.