Child support seems to be the same for Australia and the U.S., marriage isn't required for one parent to provide finanacial support for the one raising the child.
The same goes for an unmarried father not having to adopt his own child. He's the father, regardless. If, like Clark in the Becca stories, his name is erroneously put on the birth certificate he can contest it (should he believe the child is not his) or the man believing he is the biological father can contest it and a paternity test will be ordered by the court. There exists a double standard in the U.S., at least socially in some cases still, that people (usually the older generations still) that look down on an un-wed mother (regardless of whether she keeps her child or not), whereas an un-wed father that takes responsibility for his child legally, financially, and has and active part in it's life is seen as a man because he stepped up to the plate when he could have just run and hid (and been a dead-beat dad). Anyone guy can be a father, but only a real man can be a daddy.
There are two types of surrogacy: traditional and gestational. In gestational surrogacy, in vitro fertilization is used to transfer another woman's fertilized egg, or embryo, in the surrogate's uterus. Traditional surrogate motherhood involves fertilize the surrogate's own egg via artificial insemination. In traditional surrogacy, unlike in gestational surrogacy, the surrogate mother is also the biological and genetic mother (words taken verbatim from the following website):
Surrocacy US Surrogacy Laws by State Alimony is money paid (usually a monthly stipend type thing) by a former spouse as "support" to the other spouse. Traditionally it was a man supporting his ex-wife (and usually paying child support in conjunction with that) when it was less common for women to have careers or just a job. Alimony can work either way though, if one ex-spouse makes more money than the other then that person may be required to provide support.
Each state law is different (I don't think child support or alimony is regulated federally). Below are links for my state, I hope that helps you out. If anyone else has a better understanding of the laws, please correct me if I've been wrong in anything.
Alimony in the State of Connecticut, USA Child Support Law, State of Connecticut, USA
