Final answer:
The Lacey Act of 1900 paved the way for wildlife conservation in the US, leading to other significant legislations and international treaties like CITES and the MBTA. It prohibited trade in wildlife, fish, and plants that were acquired illegally, thus providing a foundation for conservation laws and regulations that followed.
Step-by-step explanation:
The Lacey Act of 1900 significantly impacted wildlife conservation efforts in the United States by prohibiting the trade in wildlife, fish, and plants that have been illegally taken, possessed, transported, or sold. This Act marked the beginning of a series of wildlife conservation legislations and was followed by others, including the Endangered Species Act of 1973, the National Environmental Policy Act of 1970, and the Clean Water Act of 1972. These acts provided a legal framework that necessitated the involvement of biologists and conservationists in the identification, protection, and recovery of threatened species and their habitats.
Internationally, treaties such as CITES, established in 1975, and the Migratory Bird Treaty Act of 1918 between the United States and Canada, further expanded the responsibilities of conservationists on a global scale. However, while these legislations and international treaties aimed to protect species and prevent illegal wildlife trade, their effectiveness often joined on the countries' ability or willingness to enforce them and contend with illegal markets.