I read that cuttlefish mostly have only one mating season and they soon die after mating. Why didn't adaptive mutation take place so that its survival is ensured even after mating. The same is the case with the worker bees. Also virus/bacteria had been in the earth for billions of years yet they did not seem to have evolved to a higher/visible beings. Can you please explain.
There are a lot of unanswered question about evolution. "Why" Questions lie in the The field of evolutionary biology. The simple answer is that things are as they are because things work out to the advantage of the species. In the opinion of any biologist including myself all changes ia a species do not occur due to random mutation. One only has to look at animal behavior and variations among insects to see that this notion is absurd.Natural selection depends upon competition but it may be taht symbiotic relationships may play a part
As to your question. The survival of the cuttlefish is assured despite the death after mating. The dying has no effect on the total population. It appears that the death is population control.. Among social insects like bees the workers literally work themselves to death but the birth rate maintians the population. Also in temperate zones weather is a factor and in cold climates there is no energy available
My students will ask me why questions in biology like why do we have two eyes instead of one and my answer is because two eyes worked out the best in keeping with the laws of physics and chemistry.