Hemoglobin titusville (described by schneider et al. in 1975) is a hemoglobin variant in which a asn residue is substituted for asp at residue 94 of the α chain.

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