Political affiliation isn't inherited. It's taught. Genetics have nothing to do with your political preference. My mom and dad were both republican, even though my mom was not officially either, but me and my brother are politically neutral, and for quite a long time now my mom has been politically neutral; she gave up on party affiliation.
First, this is not evidence against the heritability of political affiliation. Heritability is a technical term, it basically means plot parents against offspring for a particular trait and look for covariance. The heritability of height is between .6 and .7. The heritability of political party is over .8.
Note that this is a comment not about a given instance (just like tall people *can* have short parents, but on average they don't), but about population trends.
Further, your anecdote actually aligns with a high heritability - from your description, you seem to closely match your mom's political party decisions (tendency towards neutrality).
And yeah, modern technology has almost completely eliminated variation -> differential survival. Even in less developed areas, survival is more chance of situation rather than chance of genetics.
Assuming
(1) your description is true.
(2) situation does not covary with genetics.
Given that genetics and 'situation' certainly do covary, that is, certain populations are more likely to live in safer neighborhoods, or have more money, or go to college, then we can safely say 2 is wrong. Further, survival is not the ultimate measure of fitness, its number of children - and that certainly varies by population.
Since populations have different genetic compositions, this means that gene frequencies are changing across generations (because those populations that have more children contribute more to the gene pool of the next generation), and that is evolution *by definition*. It doesn't matter if the genes cause the differences that are being selected for - the population's gene pool is still responding to the selective pressures so imposed. And since some populations are more successful, that even means that they are better adapted to modern conditions than other populations, and evolution will drive the population towards that ideal.
Humans weren't populous enough at the time to actually extinct a species. It was change in climate that killed most ice age creatures.
Wrong. There is rather good evidence that humans are directly responsible for a mass extinction of mammalian megafauna in north america that pretty much coincided with the arrival of humans to the continent. I'd recommend reading papers by Alroy on the subject.