Evolution Test - 6

 Correct answer is A. A smaller head and less cranial capacity  is not a similarity between humans and apes. In fact, apes have larger heads and more cranial capacity.

• Apes have a less cranial capacity of only 650 c.c. whereas humans have a more cranial capacity of about 1300- 1600 c.c.
• Humans developed higher cranial capacity and had advanced brain than apes.

• Human evolution or anthropogenesis is part of biological evolution which studies the emergence of Homo sapiens sapiens.
• They were the distinct species from other hominids, great apes and placental mammals.

• Australopithecus was known as the connecting link between apes and man.
• They had complete erect posture and showed bipedal locomotion.
• It was the first man to stand erect.

Tendrils in plants are an example of divergent  evolution  .

Hardy-Weinberg equilibrium cannot be disturbed by vegetative propagation as the all new offspring are clone of each other having same gene. Migration, genetic drift, mutation and natural selection affect the equilibrium of alleles in a population.

Phylogenetic trees shows links between organisms that show branching pattern of evolutionary relationship. In this pattern, the organism that evolves earlier is shown below and further sub branching represent newly evolved organisms.

Human belongs to a species of Homo sapiens, where Homo represents genus and sapiens represent specific epithet under the class Mammalia.

• Natural selection mainly leads to three selections.
• They are: Stabilizing selection, directional selection, and disruptive selection.
• Technical selection does not belong to natural selection.
• This classification is based on different organism-environmental relationship.

• Stabilizing selection operates in a constant environment.
• It favors the average or complex phenotype and eliminates the extreme values.
• The mean value never changes. Also, the peak gets higher and narrower.

• Mortality in babies is an example of stabilizing selection.
• It is all depended on the baby ’s birth weight.
• The optimum birth weight is 7.3 pounds which favor this selection.
• Newborn infants with less than 5.5 pounds and more than 10 pounds have the highest mortality rate.

• This graph indicates stabilizing selection. As we can see, the peak gets higher and narrower.
• In this selection, most of the individuals acquire mean character value.

The short statured, heavy eye brows, retreating foreheads, large jaws with heavy teeth and stocky bodies humans are called Neanderthal human.

Home sapiens and Homo erectus in differ in their size of brain capacity. The size of brain of Homo erectus was smaller than Homo sapiens.

One of the first attempts to explain the mechanism of evolution was made by Jean Baptiste de Lamarck. His theory of evolution is known as Lamarckism in which he explained inheritance of acquired characters which states that whatever an individual acquires characters in its life time due to internal vital force, effect of environment, new needs and use and disuse of organs, they are inherited to the next generations. The process continues. After several generations, the variations are accumulated upto such extent that they give rise to new species.