They provide evidence of genes coding for structures that are present not because they are useful, but because they were once useful to an ancestor.
<span>One example is the plantaris muscle. This is a long, thin muscle in the human foot and calf that serves no significanl purpose in humans ... in fact, it is regularly removed by doctors harvesting muscle tissue to use in reconstructive heart surgery, because its removal leaves no loss of function in walking or balance. </span>
<span>However this same muscle is found more fully developed in the feet and calves of other primates. It is the muscle used for grasping with the feet.</span>
Answer:
<em>Scientific models</em><em> are used to predict and elaborate the behaviour of the real objects in the field of physics, chemistry, ecology and earth science. </em>
<em>It is used to gain improved </em><em>understanding of the processes and systems. </em>
Explanation:
However, every model have some limitations because they are not the representative of every possible scenario. For instance, relationship between time and distance is the idea model, study of cell and its various parts uses physical model, predicting earthquake uses computer model.
The limbic system is a set of brain structures, not a separate system which is located on both sides of the thalamus and it includes structures from the telencephalon, diencephalon, and mesencephalon. This system is involved in feeling the emotions such as joy and happiness. For example, nucleus accumbens is part of the limbic system and it is involved in reward and pleasure that can make happiness.
Besides that, the precuneus (located in front of the upper portion of the occipital lobe) is involved in feeling happiness. Scientists have shown that there is a positive correlation between the volume of grey matter in the right precuneus and the subject's subjective happiness score.
