The illustration shows bones in four animals. The bones labeled as A are known as and offer evidence of a common ancestor.
penguin
bat
alligator
human
extinct structures
sequential structures
analogous structures
homologous structures

According to theories of how life began, how did early organic molecules begin to separate from the outside world? a: specialized enzymes were required b: chains of amino acids created a barrier c: formation of microspheres or vesicles d: rna catalyzed the formation of membranes