LOL!
Years ago, the first definition of the word gay now appears as definition #2 at dictionary.com
1.) Of, relating to, or having a sexual orientation to persons of the same sex.
2.) Showing or characterized by cheerfulness and lighthearted excitement; merry.
3.) Bright or lively, especially in color: a gay, sunny room.
4.) Given to social pleasures. Dissolute; licentious.
Sucks is also listed at dictionary.com as;
Vulgar Slang. To be disgustingly disagreeable or offensive.
That is the essence of evolution, disgustingly disagreeable or offensive.
You know darn well that the phrase "That sucks" as in use today almost never refers to fellatio.
Enough said.