Well, a short story about natural selection needs to include the existence of a species with diverse traits. For instance, in a herd of deer, some have stronger antlers and some have weaker ones. The environment plays a huge role. If there is intense competition for mates, the deer with stronger antlers may have an advantage. Also, the factor of time is important. As generations pass, the proportion of deer with strong antlers may increase due to their higher success in mating and passing on their genes. So, variation, environmental pressure, and the passage of time are key elements in such a story.
In a short story about natural selection, first, there should be a group of organisms. They must have different characteristics, say different fur colors in mice. Then, there is a selective pressure from the environment, like predators preferring one color over another. The organisms that can better adapt to this pressure, in this case, the mice with the less - preferred - by - predators fur color, are more likely to live long enough to reproduce. Also, over time, this leads to a change in the population's characteristics, which is an important aspect to show in the story.
Chapter 117, "Teng Jiao Saliva and Poison Source [Two-in-One]", is the clearest early answer because it turns Beast Record's situation into a concrete plot event. Early on, Although Teng Jiao is dead, the poison mist still hasn't dispersed.... By the end, Moreover, if it had discovered us as soon as we entered the Cloud....
Chapter 58, "Giant Wooden Puppet", is the clearest early answer because it turns Giant Wooden Puppet's situation into a concrete plot event. A useful checkpoint is the way the scene starts with In the valley, at some unknown time, a Wooden Puppet Giant towering... and follows through with Leader Luo, catch this, it's the last one; cut its arm!.
Chapter 148, "Mysterious Visitor, Deciphering the Cold Resistance Level [Vote for Monthly Pass]", is the clearest early answer because it pushes Iron Refining Furnace into a new phase or setting. The chapter gives readers a real answer by opening on Listening to the voice, it seems to be... and ending on That person is really too courteous..." Xia Hong's expression was....
Chapter 100, "Clothing", is the clearest early answer because it turns Xia Chuan's situation into a concrete plot event. The chapter turns that into something concrete by moving from The second item was, unexpectedly, a set of clothing. to Turning around, Xia Hong looked at Mu Dong, with a face that grew....
Chapter 537, "Dunters", is the clearest early answer because it turns Commander's situation into a concrete plot event. A useful checkpoint is the way the scene starts with The battlefield was a chaos of fire, steel, and claws, yet through... and follows through with This battle would be the trigger for the Great War to come.. By the close, It lifted its head slightly, tilting it toward the horizon., and the chapter closes with Humanity against Demons.
Chapter 120, "Rat Swarm Unrest, Mad Bow Making [Large Chapter]", is the clearest early answer because the buildup finally cashes out in a real clash. A useful checkpoint is the way the scene starts with The six nodded, put down their chisels, and followed Xia Hong out of... and follows through with If this group of rodents discovers the valley during the day, even if....
Chapter 151, "Pioneering, The Growth of Xia Chuan [sorry, late]", is the clearest early answer because it turns Xia Chuan's situation into a concrete plot event. The chapter gives readers a real answer by opening on Because my elder brother has the qualifications, and he has the... and ending on Of course, Yuan Cheng himself is not interested in the affairs of the....
Chapter 171, "Camp Integration, Territory Rapid Expansion (Part 2)", is the clearest early answer because it turns Intermediate Cold Beasts's situation into a concrete plot event. It opens with Xia Hong made a decisive call and then said, "From today onwards, I... and closes on This whole area, about 300 square kilometers, currently constitutes....
Chapter 154, "Inheritance Rights, Strategic Contraction [Sorry for the Delay]", is the clearest early answer because Xia Hong gets a payoff that changes the stakes. It opens with They still have the leisure to battle us, these fools!" "Hahaha,... and closes on In this way, wouldn't the Great Xia gain an advantage for free!.
Chapter 4, ", Golden Finger Arrives [Please Favourite and Follow!]", is the clearest early answer because it pushes Deceitful Monster into a new phase or setting. It opens with Xia Hong gave Xia Chuan a glance and quietly handed him a hand axe. and closes on That Xia Ding was running in the opposite direction of your camp....