explain lamarks theory and also explain it's accuired characters
Answers
Explanation:
Lamarckism, a theory of evolution based on the principle that physical changes in organisms during their lifetime—such as greater development of an organ or a part through increased use—could be transmitted to their offspring.
Lamarck is best known for his Theory of Inheritance of Acquired Characteristics, first presented in 1801 (Darwin's first book dealing with natural selection was published in 1859): If an organism changes during life in order to adapt to its environment, those changes are passed on to its offspring.
For example, Lamarck believed that elephants all used to have short trunks. When there was no food or water that they could reach with their short trunks, they stretched their trunks to reach the water and branches, and their offspring inherited long trunks.
Acquired characters
Biologists define an acquired characteristic as one that has developed in the course of the life of an individual in the somatic or body cells, usually as a direct response to some external change in the environment or through the use or disuse of a part. The inheritance of such a characteristic means its reappearance in one or more individuals in the next or in succeeding generations. An example would be found in the supposed inheritance of a change brought about by the use and disuse of a special organ. The blacksmith’s arm (or any other set of muscles) enlarges when used continually against an external resistance, such as the weight of the hammer. If the effect were inherited, the smith’s children at birth would have unusually large arms—if not at birth, then when they became adults, even though they had not used their arms excessively. There is no evidence supporting this case. A more subtle illustration is found in the supposed inheritance of an increased dexterity of the hands of a musician through practice. The skill acquired, although causing no visible increase in the size of the fingers, might be imagined to be passed along to the musician’s children, and they might then be expected to play skillfully with minimal practice. Just how the intricate interplay of cerebral sequences that has given the dexterity to the musician’s fingers could ever be transferred to the musician’s sex cells (spermatozoa or ova), and through them to any potential children, has never been brought within the range of biological possibilities.
Examples of acquired characters
Acquired traits include things such as calluses on fingers, larger muscle size from exercise or from avoiding predators. Behaviors that help an organism survive would also be considered acquired characteristics most of the time. Things like where to hide, what animals to hide from and other behavior like that.
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