I think some examples or answers would help me see why this is true
Worldwide, the top causes of death are:
Starvation
Heart Disease
Stroke
and an assortment of diseases.
Pregnancy is the leading cause of death among young women under the age of 15.
These fatal conditions do not attack randomly, but differentially. They're not accidents or forces of nature. They're conditions to which the content of your heritable genes will play a role in regards to whether or not you die from them.
That's selection. Is it evolving us? It's certainly having an effect. Of course, most people have already reproduced by the time they succumb to heart disease or strokes; thus it might be more effective to examine the top causes of death for minors:
Diarrhoea
Pneumonia
Measles
Malaria
HIV/AIDS
and, of course, malnutrition.
Since these conditions, again, represent physical aliments that genetics can influence, and they eliminate humans who have not bred, this represents selection.
Are you talking about the tons of kids starving to death in africa?
Well, yeah. Starvation is a selective pressure in every environment and in every species. It's well-known as a density-depended selective factor.
I just don't see it that way. Pretty much everyone is getting laid.
Right, but not everybody is getting laid with everybody. You're not getting laid with Pamela Anderson (as a stand-in for persons with highly desirable physical traits) and neither am I. Even if you had the opportunity to ask her she'd tell you "no."
That's mate choice, and that's sexual selection. Your genes only get to combine with the genes of certain people (generally, people much like yourself in regards to the "quality" of their genes.)
How much sexual selection do you think is involved in who people are having kids with?
Unless you're having kids with literally everyone, it's all sexual selection. You selected a mate, and she selected you. It wasn't at all random. You had certain characteristics you were looking for, and so did she. You chose from a pool of avaliable mates - unless you two were the only people on a deserted island - and so did she.
Choice. Aka selection.
I think people who choose to have kids are choosing their partner for reasons other than physical attraction.
Oh, sure. Like, access to resources. Or temperment (which has a heritable component.) Or likehood of conception/successful pregnancy ("wide, childbearing hips"). Or body symmetry representing a lack of disease or crippling disfigurement. There's a significant likelyhood, based on studies of what we find attractive, that you chose a mate based on how similar her immune system was to yours - but not
too similar (because then she might be your sister.)
You didn't chose a mate at random, and neither did your mate. You look for stuff in a mate and so do your mates. Some of that is heritable and some isn't. But it's all selection.