Biology And Human Evolution
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Biology And Human Evolution
Human Biology and Evolution
Humans are Alive
The earliest human life form can be traced back more than 3.5 billion years ago. Humans are said to be descendants of a single celled ancestor. Although they are different in size and shape all basic functions are alike. The more complex the organization of the cell became the more successful and developed it became.
As these single celled organisms developed they became known as pre-humans. We share many characteristics with these pre-humans. Some of these characteristics include the masters of heredity DNA and RNA as well as proteins composed of amino acids, membranes or bound cells and lastly controlled cell division or mitosis, key to the daughter cells.
Kingdoms are Alive
The diversity of kingdoms is arranged into kingdoms that classify organisms from simple to complex. The traditional five kingdoms are Prokaryote, Protoctista, Fungi, Plantae, and Anamalia. Prokaryote is a bacterium that lacks nuclear membrane. Protoctista is a heterogeneous grouping that combines a great diversity of forms. Fungi are known for being important agents of composition they include yeast and mushroom. Plantae, are categorized as plants that use sunlight to convert to energy. Lastly Anamalia, Anamalial members are multicellular and fully mobile, they obtain their nutrients from other living things.
Our Place in Nature
Humans are hierarchically classified into a series of increasingly specific groups. They range from the Kingdom Animalia to the Genus Homo, the Homo Sapiens appears to be its only living representative
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertabrata
Class: Mammalia
Family: Hominidfae
Genus: Homo
Our Place in time
Over a considerably large span of geological time life on earth has changed drastically. Humans and their close relatives are the most recent arrivals in the Tertiary period. The periods range Precambrian which was over 56 million years ago to Quaternary which was 1.8 million years ago to present. In this chart you will be able to see all periods ranging from Precambrian to Quaternary.
TABLE
PERIOD AGE
(MILLIONS OF YEARS) SOME IMPORTANT EVENTS IN THE HISTORY OF LIFE
Quaternary 0.01
1.8 Historic time
ice ages; humans appear
Tertiary 5
65 Apelike ancestors of humans appear
major radiation of mammals, birds, and pollinating insects
Cretaceous 144 Flowering plants appear; dinosaurs and many groups of organisms become instinct at end of period
Jurassic 208 Gymnosperms co...
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