system
Given the following post, respond as if you're commenting on Reddit:
human
How did the evolution that produced the Angler fish work, especially the sexual dimorphism?

If evolution is just a series of small mutations, wouldn't males getting smaller and weaker jaws make them less likely to survive? How did the parasitism even evolve? Did a male angler fish suddenly think, okay I'm just going to bite this female, and somehow they fused?
gpt
So consider the environment most angler fish live in. Most live in dark areas with limited resources. To make things harder they eat living things rather than dead things. Living things are kind of rare, but it's how the angler fish do. The female is the primary producer of children, so in order to produce lots of children you need a lot of energy. This can't happen if you are competing with your own species. So to combat this the males get smaller and require less energy. In addition, males are programmed to seek out the female and attach. Some females in nature (namely geckos) store sperm cause your don't know when the next meeting will be. Angler fish take this a step further and basically collect gonads.

Edit:a word.