Afarensis is a 3.5-2.8 million year old hominin from the Kada Hadar member of the Hadar formation in the Middle Awash, Ethiopia. He is approximately 41 inches tall, weighs approximately 60 pounds and has a cranial capacity of a whopping 410 cc (approximately). Afarensis is currently considered to be transitional between apes and humans and displays some traits of both. Since he spends a lot of time on the couch watching monster movies, some observers question whether he is an obligate biped (although no one has observed him climbing a tree). He also has a blog called 
BMC Biology has an interesting study of call divergence in mouse lemurs.
(The research examined advertisement calls and alrm calls in three species of mouse lemurs. Two of those species were sympatric, while the third was allopatric. The research was performed on wild caught specimens that were trapped and brought to a lab (the lemurs were subsequently released). Based on their experiments, the researchers conclude:
This study provides the first evidence in primates for specific acoustic divergence in the
communication of cryptic species living in sympatry. Advertisement calls of sympatric
species essential in the reproductive context differed distinctly in their structure whereas
whistle calls irrelevant for reproduction did not. On the perception side mouse lemurs
discriminated between the species-specific advertisement calls and preferred conspecific
to sympatric calls. Thus, our data support the evolutionary hypothesis that species
cohesiveness in sympatry has led to specific divergence in signaling and recognition
systems in order to avoid costly hybridization.
This is similar to the results on calls in Darwin's finches...
Life Science
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