Biology [2 Mark Question Answer]

There have been several changes in the chin and brows throughout human evolution. The chin is a unique feature of the human face that is absent in other primates. Scientists believe that the chin may have evolved as a result of changes in our diet. In contrast, changes in the brow ridge have been seen throughout human evolution, with earlier hominids having more prominent brow ridges as compared to modern humans.

Darwin's concept of "survival of the fittest" refers to the process of natural selection, where organisms that are better adapted to their environment are more likely to survive and reproduce. The individuals that possess traits that are advantageous for survival will have a greater chance of passing on these traits to their offspring, leading to the evolution of the species over time.

Lamarck explained his concept of evolution through the theory of inheritance of acquired characteristics. He believed that organisms could pass on traits that they acquired during their lifetime to their offspring, leading to evolutionary change. Lamarck also proposed that organisms change in response to their environment, with their needs and desires shaping their physical traits over time.

Bipedalism provided several benefits to Homo sapiens, such as increased efficiency in walking and traveling long distances, freeing up their hands for other tasks like carrying objects or using tools, and better visibility of the surrounding environment to spot prey, predators, and resources. Additionally, it allowed for greater agility and adaptability to changing environments.

(i) Evolution is a gradual process that can involve mechanisms of selection, such as natural selection.
(ii) Lamarck's theory of evolution is based on the idea that acquired traits cannot be inherited.

(i) Lamarck's theory of evolution proposes that organisms can acquire traits during their lifetime that can be passed on to their offspring. In contrast, Darwin's theory of evolution proposes that traits are inherited through natural selection, and that individuals with advantageous traits are more likely to survive and reproduce.
(ii) Lamarck observed that organisms have an innate drive to adapt to their environment, and that this drive can result in the acquisition of new traits over the course of an individual's lifetime. He also observed that these acquired traits can be passed on to offspring, leading to evolutionary change over time.

Darwin's theory of evolution proposes that all living organisms on Earth are related through a common ancestor and have evolved over time through the process of natural selection. Natural selection is the process by which individuals with favorable traits are more likely to survive and reproduce, passing those traits on to their offspring. Over time, this can lead to the emergence of new species and the diversity of life we see today.