In the popular mind, mass extinctions are associated with catastrophic events, like giant meteorite impacts and volcanic super-eruptions. But the worldâs first known mass extinction, which took place about 540 million years ago, now appears to have had a more subtle cause: evolution itself. âPeople have been slow to recognize that biological organisms can also drive mass extinction,â said Simon Darroch, assistant professor of earth and environmental sciences at Vanderbilt University.
The pectoralis major (/ËpÉktÉËreÉªlÉ¨s ËmeÉªdÊÉr/) (from Latin: pectus, breast) is a thick, fan-shaped muscle, situated at the chest (anterior) of the human body. It makes up the bulk of the chest muscles in the male and lies under the breast in the female.he pectoralis major (/ËpÉktÉËreÉªlÉ¨s ËmeÉªdÊÉr/) (from Latin: pectus, breast) is a thick, fan-shaped muscle, situated at the chest (anterior) of the human body. It makes up the bulk of the chest muscles in the male and lies under the breast in the female.
What Does the Brain Do? The brain is the control centre for all the bodyâs functions, such as walking, talking, swallowing, breathing, taste, smell, heart rate and so on.t also controls all our thinking functions, our emotions, how we behave and all our intellectual (cognitive) activities, such as how we attend to things, how we perceive and understand our world and its physical surroundings, how we learn and remember and so on.