Selection, Natural and Artificial

Selection, Natural and Artificial

1.Natural Selection

Natural selection is the process by which individuals best adopted to their particular environments tend to survive in the struggle for life.

2. Mutual Aid

Survival does not always depend upon the individual; it may result from group actions. It is argued that mutual aid is a factor in the survival of some individuals and groups.

3. Artificial Selection

Man in his society also does much of the selection.

-Eugenics. An attempt to improve the quality of offspring by selective mating is referred to as eugenics.

-Sterilization. Laws have been passed which provide for the sterilization of certain classes of individuals, such as epileptics, feeble-minded, insane, and habitual and incurable felons, to prevent the reproduction of their kind.

-Birth Control. It is the use of contraceptives for birth prevention.

4.Warfare and Natural Selection.

A form of human selection which operates in a fashion to counteract the principles of the survival of the fittest is that resulting from modern warfare.

Human Variations and Similarities

Human Variations and Similarities

1.Variations Due to Heredity

Variation takes different forms. There are variations in sex; some people are males and other are females, with no intermediate types except in pathological cases.

2. Somatic Variation

Another type of variation is that due to environment. Environments includes  geographic conditions and the conditions arising out of association with life of the same or other species.

Distinctive Human Traits

DISTINCTIVE HUMAN TRAITS

 (a)Upright Posture,

 Important development in human evolution was the adoption of upright posture by the early ancestors of man.

(b) Hairless Body,

Another feature which distinguishes man from his cousins, the apes, is his hairless, or nearly hairless, body.

 (c) Head and Brain,

The head of man rests on the vertebrae like a ball on a pedestal, whereas the typical quadruped has its head thrust forward from the neck.

 (d) Human Powers and Adjustment,

Associated with man’s remarkable brain is the human power of adjustment to his surroundings and to new situations.

(e) Speech

One of the characteristics of man which distinguishes him from the anthropoid apes is his power of articulate speech.

Modern Man

Modern Man

Modern man is divided into three major races which are distinguished by hereditary physical traits.

These major races of man are:

(a)the Caucasian or white,

(b) the Mongolian or yellow, and

(c) the Negro or black

The major races are further subdivided into sub-races.

The Fossil remains closely associated with the development of man

The Fossil remains closely associated with the development of man

The early forms of life which are closely associated with the development of man are to be studied in the fossil remains which have been found in different parts of the world.

The most important of the fossil remains are:

(a) The  South African Ape-man,

(b) Pithecanthropus erectus, or the Java Ape-man

(c) Peking man

(d) Neanderthal man,

(e) Cro-Magnon man(Homo sapiens)

The evidence of evolution of man

Evolution of Man

The evidence of evolution of man are to be found:

(a)Paleontology,

(b) Mutations,

(c) Embryology

(d) Comparative anatomy,

(e) Comparative physiology, and

(f) Domestication

Certain characteristics of life are:

Certain characteristics of life

Certain characteristics of life are:

(a) Protoplasm,

(b) Cellular structure,

(c) Nutrition and metabolism,

(d) Movement,

(e) Growth and reproduction, and

(f) Continuity or heredity