Contents: Human Ancestry | Diversity Time scale | Clades

Evolution of Man (Much of this is theory which is continuing to evolve.)
See Creation - Evolution - Intelligent Design for the "Creationist" view.

Biologists have long aspired to paint a genetic portrait of the ancestor by running the tree of evolution backward, going from its leaves -- the living creatures of today -- down to the point where all its branches coalesce in a single trunk.
Scientists have been using DNA analysis to help in this excercise, but it has turned out to be more complicated than they thought. (see below)

The rapid (geologically speaking!) diversification of the animals has made it difficult to establish the genealogical relationships between them.

Some reptiles changed so that they could be active even when it was cool. These were the warm blooded cynodonts. They may have had fur to help keep them warm. They could feed at night when other reptiles could not. A new mammal, the primate, appeared about 65 million years ago. The monkeys evolved first and then the apes.

Earliest Mammal Found 04/25/2002 mouse-sized shrew. Its discoverers date it at 125 million 50 million years older than the previous record holde

most ideas and theory on animal evolution are based on:

• fragmentary fossil record
• comparative anatomy
• comparative embryology
• comparative biochemistry

ARCHAEA [Domain]
Bacteria (single cell, no nucleus) 3bya
Eukaryotes [Domain]
 Protozoa (Cells with a nucleus) 1.2 bya
 Animalia [Kingdom]
 Sponges [Phylum Porifera] (Grouping of cells in an organized colony) 0.8-1bya
    JellyFish (primative nervous system and muscles) 600 mya
     Coral
      Flataworms (Phylum Platyhelminthes)  600-1,000 mya
        (beginnings of a head - mouth and light sensitive spots)
       Brachiopods
       Mollusks [Phylum]
        Nautilus  550 mya
        Trilobites (High-definition eyes)
         Squid
         Echinoderms [Phylum] (star fish) 540 mya
           Lancet Family Alepisauridae (protofish) (Cephalochordata, Amphioxus 440 mya
         Chordata [Phylum] nerve chord.  570 mya
           Urochordata [Class] (Sea Squirts, Tunicates, Ascidians, etc.)
          Vertebrates [Sub-Phylum] 525 mya
            Agnathans are jawless fish. There are two primary marine types of the class Agnatha.
            They are Hagfish and Lampreys. 500mya 440mya
              Bony Fish - 470mya
              Fish  400 mya
             Coelacanth (Lungfish) 350 mya
              Tetrapods (terrestrial vertebrates - 4 appendages legs or legs+wings) 350 mya
               Amphibians 
                Synapsida [Class]- (extinct) (looked like reptiles) (300 mya) 
                 Pelycosaurs ("mammal- looked like reptiles") 290 mya
                  Therapsida [Order]- The dominant land animals during the Middle Permian.
                
                   Early Mammals [Class] (shrew like) 225mya
                    Marsupial (Opossum) 65mya
       
Early primates [Order] 50 mya
 Hominoids [SuperFamily] (Gibbons, ..) 20 mya
  Hominidae [Family] (Orangutans, ..) 15 mya
   Homininae [Sub-Family] (Gorilla, man, chimp) 12 mya
    Ardipithecus ramidus 4.4-5.8 mya
    Astralopithecus [Genus] 3-4 mya
      Anamensis 4.2-3.9 mya
      Afarensis 3.9-3 mya (Lucy)
      Africanus 3-2 mya
      Robustus 1.8-1 mya
    Homo [Genus] 1-2 mya
     Homo Habilis [Species] 1.6-1.9 mya
     Homo Erectus [Species] 300,000-1.8 mya
      Homo sapiens (archaic) [Species] 80,000-300,000 yrs
       Homo neanderthalensis 33,000 - 300,000 yrs
       Homo Sapien Sapien (Modern Man) 60-120,000 yrs

bya - Billion Years ago
mya - Million Years ago

First appearances and relative diversity (width of shaded area) for major groups of animals.

Source: The Modern View Of Evolution at Estrella Mountain Community College from Life: The Science of Biology, by Purves et al., from Sinauer Associates.

Life evolved very slowely until the cambrian explosion about 530 million years ago.
Gould proposed (in Wonderful Life, 1989) that all modern animal phyla had appeared rather suddenly. But other analyses, argue that complex animals similar to modern types evolved well before the start of the Cambrian.

Origins of Life:
1938 - The Origins of Life

In "The Origins of Life", Russian biochemist, Alexander Oparin, published a theory of how chemical reactions with simple gases such as ammonia (NH₃), methane, (CH₄), water (H₂O), carbon dioxide (CO₂) and hydrogen (H₂) combined with ultraviolet radiation could have produces other compounds to make amino acids, sugars, phosphates and other building blocks of complex molecules (such as proteins) necessary to living cells.

1953 - Miller-Urey Experiment
While doing graduate work under Harold Urey at the University of Chicago, Stanley Miller conducted the first experimental test of the Oparin model. He sent a high-voltage charge of electricity into the chamber filled with methane (CH₄), ammonia (NH₃), water vapor (H₂O) and hydrogen (H₂). After two days Miller found a small (2%) yield of amino acids.
According to Dembski in Mere Creation, there are several problems with this theory based on current knowledge including the lack of nitrogen, the speed with which life emerged and complexity of living cells.

2001 To answer the question of which came first a cell membraned or genetic molecules, Szostak, Bartel and Luisi's paper "Synthesizing Life" (Nature. 2001; 409: 387-390) state that a protocell and genetic molecule had to develop in parallel.

Szostak at Mass. General has shown since how simple fatty acids around in the primative earth could form cell membranes.

2009 - Sutherland article in Nature
John Sutherland, a chemist at the Univ. of Manchester published an article, "RNA world easier to make", Nature, 13 May, 2009, describing his discovery of a route for synthesizing nucleotides from prebiotic chemicals.

See also: Earth History and Extinctions.

Clade	ToL	UCMP
Root
Eukaryotes - Multi-celled with nucleus
Animals (Metazoa)
Bilateria - bilaterally symmetrical (front/back, left/right)
Deuterostomia - Develop (embryo) mouth second
Chordata - Hollow nerve cord
Vertebrates - backbone
Terestrial Vertebrates/Tetrapods
Aminiota (mammals, reptiles)
Synapsida - Reptilian like creatures 300 mya
Therapsida - Order under Synapsida
Mammalia
Eutheria - Placental (unborn children carried in the uterus)
Primates
Catarrhini (Humans, great apes, gibbons, Old World monkeys)
Hominidae (great apes)

DNA:
The longstanding road map for finding the universal ancestor turns out in the light of new data to have given misleading directions, and the road map's chief author, Dr. Carl Woese of the University of Illinois, is proposing a new theory about the earliest life forms.

Scientists have been using DNA analysis to help in this excercise, but it has turned out to be more complicated than they thought. A basic source of the confusion is that in the course of evolution whole suites of genes have apparently been transferred sideways among the major branches. Among animals, genes are passed vertically from parent to child but single-celled creatures tend to engulf each other and occasionally amalgamate into a corporate genetic entity.
See April 14, 1998 NY Times Article "Tree of Life Turns Out to Have Complex Roots"

Books:
Darwin's Ghost : The Origin of Species Updated, 2001, S. Jones
"The Growth of Biological Thought", Ernst Mayr
"Full House", 1996, Steven Gould
"Life Evolving", 2002, Christian de Duve
Life On Earth, 1979, Attenborough A book and TV series from the BBC
The Origins of Life, A. I. Oparin, 1938 (English Translation)

See:
Understanding Evolution at UC Berkeley
Classification: Taxonomy & Systematics (History of Classification and evolution)
The Tree of Life Web Project (ToL) is a collaborative effort of biologists from around the world. On more than 3000 World Wide Web pages, the project provides information about the diversity of organisms on Earth, their evolutionary history (phylogeny), and characteristics.
Origin And Evolution Of Life at the Encyclopedia of Science
THE EVOLUTION OF LIFE ON THE EARTH Scientific American Article by Steven J. Gould
The Evolution of Mammals
Evolution Library ( Origins of Humankind, ) at pbs.org
Creation - Evolution - Intelligent Design
Tree of Life: Vedrtebrtates at the American Museum of Natural History
Systemataics of Vertebrtes Univ. of California Museum of Paleontology (UCMP)
The Invertibrate Animals
Evolution Directrory at ActionBioscience.org
http://mcb.harvard.edu/BioLinks/Evolution.html Evolution at Molecular and Cellular Biology Dept at Harvard
Human Evolution M.Tevfik Dorak, B.A. (Hons), M.D., Ph.D.
Nature and Origin of Life on Planetary Bodies
Institute of Human Origins at Arizona State U.