Sat 7 Nov, 2015 01:11 pm
Wikipedia says androgens are the precursor to all estrogens. Lampreys, however, a type of fish said to have evolved 450 million years ago, have an estrogen receptor but not an androgen one. Are the estrogens still converted from androgens in this species, or have many species that have come thereafter developed an interesting, albeit not fundamentally required, way to create estrogen?
When they say "precursors", they mean chemicals that can be broken down to produce estrogen after undergoing certain processes. It does not necessarily mean that animals used androgens before they used estrogen.