Creepy
by Jeff
Image text: And I even got out my adorable new netbook!
This comic is a dream sequence for the male character for the first four frames. It appears to be a social commentary about why more single men and women don't randomly talk to each other. One side is waiting for the other to show the midlest interest and the other side is waiting for the other side to show interest as well. So, no one talks to anyone else and someone writes sadly into their blog.
Brontosaurus
by Jeff
Image text: Well, sex is like a velociraptor: despite your movie-fueled lifelong neurotic obsession, unlikely to be found in your house.
And here we continue xkcd's author's obsession with the cyncism about love.
Brontosaurus is an obsolete phrase for the Apatosaurus. Brontosaurus is the "popular" (but incorrect) name for the dinosaur, but Apatosaurus is the correct name.
Date
by Mike
Image Text: Well, the kid's definitely getting the biology geek phenotype.
Punnett squares are simple diagrams used to determine the odds of a particular offspring genotype (genetic make up) given the genotypes of the parents. The phenotype is the physical manifestation of the genes in the organism and doesn't always correlated directly to strict genotypes. Some genetic characteristics (like color blindness and eye color) can be easily traced using Punnett squares because they are the result of one clearly dominant gene and one clearly recessive. Other traits like height are a blend of multiple genes.
An interesting thing to note:
The male's parents were both colorblind but that is a recessive gene on the X chromosome. For his mother to be colorblind she must have had two copies of the gene. This man now carries the gene on his X chromosome so he will only pass it on to his daughter. She will be a carrier but will have normal color vision so long as this woman is not colorblind.
Suspicion
by Jeff
Image text: Fine, walk away. I'm gonna go cry into a pint of Ben&Jerry's Brownie Batter(tm) ice cream [link], then take out my frustration on a variety of great flash games from PopCap Games(r) [link].
In this comic, the main character is having online chats with what appears at first glance to be a woman. However, in requesting that they both "get tested". The woman on the other end of the computer does not pass a CAPTCHA test and is unable to prove she is a human.
This is an internet version of the Turing test. A spambot is a program that send out links (such as in the image text) to simulate an human's writing. This test is called "VK", which stands for Voight-Kampff, which is the machine in Blade Runner which determines human from replicant.
In using the phrase "get tested", the comic is making a pun that refers both to the CAPTCHA test above and the STD test that couples will take to make sure they are physically clean.