Scientists believe it takes around two million years for a new species to come into existence. Species extinction, on the other hand, can occur in the comparative blink of an eye. Unfortunately, North America’s imperiled flora and fauna aren’t getting the help they need from congressional leaders in Washington, D.C., putting more and more species under threat.

Since the start of the 114th U.S. Congress a mere 16 months ago, the Endangered Species Act has come under legislative attack a total of 100 times, according to a tally released this week by Defenders of Wildlife.

Unless you’re paying close attention, these 100 attacks against one of our nation’s strongest environmental laws aren’t obvious. Proposals to delist or block the listings of individual species, such as the gray wolf or the Northern long-eared bat, are often stealthy, tucked away in extremely complicated must-pass bills like the federal defense budget.

And as we’ve pointed out in our “Political Animals” feature, D.C. lawmakers have used at least seven different tactics to try to water down the Endangered Species Act. These range from introducing bills that exclude entire states or regions from following conservation requirements under the Endangered Species Act to floating legislation that bogs down scientists in bureaucracy.

Anti-wildlife legislators have made repeated bids to dismantle the law despite widespread public support for wildlife protections. Recent polling found that 90 percent of U.S. voters across the political spectrum support the Endangered Species Act.

So if voters are happy with federal safeguards for rare and iconic species, what’s driving these attacks? With threats of extremist violence, a vacancy on the Supreme Court and an ongoing presidential election to worry about, what lawmaker has time to take legislative pot shots at the lesser-prairie chicken?

Here’s a hint from Defenders of Wildlife:

“It is the polluters, extractive industries and developers that have these members’ ears. These special economic interests have wanted to weaken or eliminate the Endangered Species Act’s protections for decades, making it a scapegoat for all types of economic maladies. Today there are too many members in Congress willing to do their bidding.”

Under the Endangered Species Act, oil and gas interests, commercial real estate developers, utilities, agricultural interests and others must engage in consultations to ensure their operations won’t harm protected species. At the end of the day, the incentive to gut these protective measures boils down to industry’s desire to act as it wishes without any impediment or regard for the impact it will have on America’s wildlife.

Worse yet, these attacks on the Endangered Species Act are being waged in the context of what some biologists have termed Earth’s “sixth mass extinction.” Humans are to blame, the Washington Post points out, reporting on a study that concluded our  planet is losing mammal species at 20 to 100 times the rate of species loss in the past. On a global scale, biodiversity is vanishing at a rapid and alarming rate, and federal lawmakers should be doing everything in their power to slow this trend.

For plants and animals facing extinction in the U.S., the Endangered Species Act is their last line of defense. And it’s been wildly successful, preventing 99 percent of protected species from going extinct. Tell Congress to leave the Endangered Species Act intact.