What was lamarck's theory and why was he incorrect?

Lamarck believed that an organism that adapted to change would pass that adapted trait to it's offspring. he was incorrect because those changes dont get passed on through genetics

Three reasons of the deaths of native americans: new illnesses that their immune systems couldn't cope with. genocides so the settlers could have the good land.starvation from lack of rations and poor infertile land on resevations