User:Acather96/Drafts/Evolution of the heart

The study of the evolution of the heart encompasses the the biological events and processes involved in the origin, elaboration and diversification of the heart across the animal kingdom. Originating approximately 500 million years ago, the heart is the central pump in the circulatory system, acting to distribute oxygen and nutrients and remove waste products.

A common misconception of cardiac evolution is that hearts always increase in complexity over time: scientists now know that in many animal lineages natural selection has driven the 'loss' of pumping circulatory organs. Our understanding of the evolution of the heart is also being enriched by the discovery that conservation at the molecular level for the development of a given structure between species does not necessairly imply structural homology.