HUMAN ORIGIN

The tree of life: Where we come from is an interesting question and nice to know.

 What is human evolution?

Recent studies indicate that the humans (Homo sapiens) and chimpanzees (Pan troglodytes) are between 95 and 98.5 percent genetically identical. So, humans must have developed from the same primates or ape-like ancestors.

Hominids fossils from the past 7 million years:

Sahelanthropus tchadensis (Sahel hominid from Chad) or Toumai (hope of life) - 7 million years old discovered in 2002.
Orrorin tugenensis - 6 million years old; discovered in Kenya
Ardipithecus kadabba - 5.5 to 5.8 million years old; discovered in an Ethiopian desert in 2004.
Ardipithecus ramidus - 4.4 million years old; discovered in Ethiopia in 1994
Australopithecus afarensis- Lucy 3.6 to 2.9 million years old; discovered in Hadar, Ethiopia.
Australopithecus anamensis
Australopithecus bahrelghazali
Australopithecus gahhi - 2.5 million years old; discovered in Bouri, Ethiopia.
Australopithecus africanus
Paranthropus aethiopicus
Paranthropus boisei
Paranthropus robustus
Kenyathropus rudolfensis
Homo habilis - 1.9 million to 1.6 million years old; discovered in Olduvai Gorge, Tanzania; the first hominid to use tools and start eating some meat.
Homo ergaster
Homo antecessor
Homo heidelbergensis
Homo erectus - 1.8 million years to 300,000 years old; general diet included meat; body height ranged from 5’ 3” to 5’ 11”.
Homo neanderthalensis - 150,000 years to 30,000 years old; disappeared from the earth 30,000 years ago.
Homo sapiens idaltu - the oldest modern human -160,000 years old; discovered in the Ethiopian village of Herto in 1999.
Homo sapiens sapiens

Here are the few websites that provide additional information:

http://www.becominghuman.org : becoming human

http://www.mnh.si.edu/anthro/humanorigins : human origins
http://history.evansville.net/prehist.html : prehistory

Here is a summary of human evolution:

Humans and chimpanzees descended from, a single apelike primate that remains to be discovered, and is estimated to have originated 8 to 10 million years ago.

7 million years old, our first human ancestors (hominid species), the Toumai (Sahelanthropus tchadensis) separated from the ape (discovered in the central African region named ‘Sahel’ in Chad); their diet consisted mainly of fruits, leaves and seeds; the body height about a Chimpanzee’s height (4 feet tall).

About 2 million years ago, Homo habilis starting using primitive tools for scavenging for meat besides eating fruits, tubers, leaves, body height 3’ 11” to 5’2”, the first intellectual flowering.

1.8 million years to 300,000 years old - Homo erectus used more sophisticated tools and hunted for food rather than scavenging for food; general diets included meat, and body height ranged from 5’ 3” to 5’ 11”.

According to paleontologists, several hominid species probably coexisted in the same time period.

Homo sapiens idaltu - the oldest modern human- 160,000 years old; was discovered in 1999 in the village of Herto in Ethiopia.

According to genetic studies of mitochondrial DNA, it is likely our ancestors came from Africa (out of Africa theory) and then spread all over the world 100,000 years ago.

100,000 years ago - migration out of northeast Africa toward Asia.
50,000 to 60,000 years ago – hominids reached Southeast Asia and Australasia.
40,000 years ago – they reached Europe.
15,000 to 35,000 years ago – they traveled across the Beringia, from Russia to Alaska, North and South America

Reasons we evolved into modern humans:

1. We moved from the forest into partially wooded and savannah areas. It was also due to weather changes or environmental changes.
2. Bipedalism - we walk with our two legs, to avoid hot weather (taller)
3. Using tools (brain size larger)
4. Eating meat and fat especially omega 3 fatty acid (brain size larger)
5. Genetic mutations.

Basic knowledge and glossary

The definitions
Anthropology: Science dealing with humans.
Archeology: study of past human life.
Fossil: any rock or mineral, hardened remains dug out of the earth, or traces of plant or animal life of some previous geological period, preserved in rock ornaments in the earth‘s crust.
Geology: The science dealing with the physical nature and history of the earth.
Paleontology, paleontologist: subject and person that deals with prehistoric forms of life through the study of plant and animal fossils.
Hominid: any of a family of two-legged primates including all forms of man, extinct and living.
Homo: any genus of primates comprising of man and several extinct species of man.
Sapiens: wise, full of knowledge.
Homo sapiens sapiens: modern human species.
Genus: classification of plants or animals with common distinguishing characteristics. A genus is the main subdivision of the family and made up of a small group of closely related species or a single species.
Species: biological grouping of closely related organism or the fundamental biological classification, comprising a subdivision of a genus and of a number of plants or animals all of which have a high degree of similarity.
Herbivorous: feed on plants.
Omnivorous: eat both meat and vegetables.
Carnivore: flesh-eating animal.
Carcass: a dead body.
Dimorphism: the occurrence of two types of individuals in the same species.
Bipedalism: two-footed.
Glacial epoch or Ice Age: Any period of geological time when large parts of the earth were covered with glaciers. The last Ice Age, called Pleistocene, started 35.000 years ago and continues to last even until the present day.