Expalin the features of modern human beings that differentiated from their ancestors.
Answers
Explanation:
Three important features of modern human beings that differentiate them from their ancestors are: (i) A bigger and developed brain with increased capacity for cognitive behaviours like perception, memory, reasoning, problem solving, and use of language for communication. (ii) Ability to walk upright on two legs.
Answer:
In many ways, what makes a modern human is obvious. Compared with our evolutionary forebears, Homo sapiens is characterized by a lightly built skeleton and several novel skull features. But attempts to distinguish the traits of modern humans from those of our ancestors can be fraught with problems.
Decades ago, a colleague and I got into difficulties over an attempt to define (or, as I prefer, diagnose) modern humans using the skeletal morphology that is preserved in fossils. Our attempt was well-intentioned: we were trying to set up strict criteria, based on cranial measurements, to test whether controversial fossils from Omo Kibish in Ethiopia were within the range of human skeletal variation today — anatomically modern humans
: ILLUSTRATION BY CHRISTIAN DARKIN
Our results suggested that one skull was modern, whereas the other was non-modern (or, in palaeontological terms, archaic). What I did not foresee was that some researchers who were not impressed with our test would reverse it, applying it back onto the skeletal range of all modern humans to claim that our diagnosis wrongly excluded some skulls of recent populations from being modern. This, they suggested, implied that some people today were more 'modern' than others. Although I disputed what I considered to be a misuse of our test, I had to recognize the dangers inherent in this prescriptive approach to modern human variation.
Today, scientists are facing a similar situation. In 2010, DNA evidence showed that after modern humans left Africa about 60,000 years ago, they bred for a short period of time with archaic humans — and, as a result, some populations today have more archaic genes than others. These genes might be expressed in the phenotype, and may require a rethink about how and when regional variation developed in H. sapiens. Those with alternative agendas may also try to use these new data to rank modern human populations in terms of supposedly different degrees of modernity. Already I'm reading blogs that speculate about whether some groups are less 'modern' than others, and I fear that such discussions endanger the considerable progress promised by palaeogenetic research.