Are sentences 3 and 4 a good thesis statement in a persuasive essay on saving endangered animals? If not, how can it be improved on?
Extinction started out as a natural process before the arrival of humans. Countless species have gone extinct through the process of natural selection. The dinosaurs are the best known example of this. Today, man has populated the Earth to such an extent that habitat destruction and animal poaching are now the primary causes of species decline. In order to make room for our ever-increasing population, humans have slashed, burned, and chopped their way into habitats, destroying species at a rate faster than they can replenish themselves. Each person can contribute in even small ways to help save endangered animals.
The introductory paragraph has an appropriate structure and thesis. The strength of this thesis will really depend on the rest of the paper. "Each person can contribute...to help save endangered animals" is a good statement. You might consider removing "in even small ways" from the sentence to make your thesis more concise. If this is a persuasive essay, you might want to change "can contribute" to "should contribute" but that really depends on what you are trying to prove. The statement that people "can contribute" sounds like you will be discussing the various options available. This might easily become more expository than persuasive. The statement that people "should contribute" suggests that you will be trying to convince your audience why people should act rather than just how. You can still write about the small ways people can help but from the perspective of persuasion rather than a simple statement of fact. This means you should try to convince people that they should do these things and that these small steps are too simple not to do.