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.
Video Transcript. Hi, I'm Michael Carson here to discuss with you what muscles do dumbbell pullovers work. Now, the pectoral major is the main muscle that is working when doing the dumbbell pullovers but you also get the pec minor.You get the latissimus dorsi, the larger muscle of the back, you get your teres major and your teres minor.ow, the pectoral major is the main muscle that is working when doing the dumbbell pullovers but you also get the pec minor. You get the latissimus dorsi, the larger muscle of the back, you get your teres major and your teres minor.