history of humans timeline
extinction of Australopithecus
earliest apes amongst the primates (early Miocene period), enlarged brain
First complex stone blades and grinding stones
Some hominids develop meat-rich diets as scavengers, the extra energy may have favoured the evolution of larger brains
Urmetazoan: The first fossils that might represent animals appear in the 665-million-year-old rocks of the Trezona Formation of South Australia. These fossils are interpreted as being early sponges. [7] Separation from the Porifera (sponges) lineage. Eumetazoa/Diploblast: separation from the Ctenophora (“comb jellies”) lineage. Planulozoa/ParaHoxozoa: separation from the Placozoa and Cnidaria lineages. Almost all cnidarians possess nerves and muscles. Because they are the simplest animals to possess them, their direct ancestors were very probably the first animals to use nerves and muscles together. Cnidarians are also the first animals with an actual body of definite form and shape. They have radial symmetry. The first eyes evolved at this time.
Urbilaterian: Bilateria/Triploblasts, Nephrozoa (555 Ma), last common ancestor of protostomes (including the arthropod [insect, crustacean] and platyzoan [flatworms] lineages) and the deuterostomes (including the vertebrate [human] lineage). Earliest development of the brain, and of bilateral symmetry. Archaic representatives of this stage are flatworms, the simplest animals with organs that form from three germ layers.
No. Humans are one type of several living species of great apes. Humans evolved alongside orangutans, chimpanzees, bonobos, and gorillas. All of these share a common ancestor before about 7 million years ago.
The primary resource for detailing the path of human evolution will always be fossil specimens. Certainly, the trove of fossils from Africa and Eurasia indicates that, unlike today, more than one species of our family has lived at the same time for most of human history. The nature of specific fossil specimens and species can be accurately described, as can the location where they were found and the period of time when they lived; but questions of how species lived and why they might have either died out or evolved into other species can only be addressed by formulating scenarios, albeit scientifically informed ones. These scenarios are based on contextual information gleaned from localities where the fossils were collected. In devising such scenarios and filling in the human family bush, researchers must consult a large and diverse array of fossils, and they must also employ refined excavation methods and records, geochemical dating techniques, and data from other specialized fields such as genetics, ecology and paleoecology, and ethology (animal behaviour)—in short, all the tools of the multidisciplinary science of paleoanthropology.
“These are just naturally occurring rocks that, over time, have broken along existing fractures,” says Texas A&M University archaeologist Michael Waters. “The evidence for early human occupation is not there.”
Holen says he knew his paper would ignite controversy, and that he’d be the first to admit “you need to have more than one site if you’re going to have a paradigm shift.” He hopes more researchers will remain open-minded.
Resources:
http://www.newscientist.com/article/dn9989-timeline-human-evolution/
http://en.m.wikipedia.org/wiki/Timeline_of_human_evolution
http://www.britannica.com/science/human-evolution
http://www.discovermagazine.com/planet-earth/human-evolution-timeline-topples
http://neuroclusterbrain.com/multiple_personality_disorder_history.html