There is higher abundance of lighter elements in the universe than heavier elements. which sourfe of evidence supports that statement
Cosmic Microwave Background Expanding Universe Universe Composition​

Due to its formation in the supernova nucleosynthesis.

Explanation:

The higher abundance of lighter elements in the universe than heavier elements occurs due to its formation in the supernova nucleosynthesis. The lighter elements such as hydrogen and helium are present in abundant amount and formed in supernova nucleosynthesis as compared to other heavier elements which are formed through other events. The lighter elements occupy less volume and space as compared to heavier elements which is also a reason for their abundance.

≅200-130 milions years ago pangea splited in 2 continents

answer; ///(b) it is composed of four protein chains and four heme groups;