The doodle presents illustrations and facts about six unique species that represent a variety of different life forms.

"The last thing I wanted to do was feature animals based on their cuteness or how they might appeal in some way to my mammalian sensibilities," lead artist Kevin Laughlin said. "We tried to focus on having a good range of organisms from around the globe that all had an extra special unique quality or earthly superlative."

The featured species are:

1. The wandering albatross, which has the widest wingspan of any bird.
2. The coastal redwood, which is the tallest tree in the world.
3. Paedophryne amauensis, which is both the smallest frog and the smallest vertebrate in the world.
4. The Amazon water lily, which is one of the world's largest aquatic plants.
5. The coelacanth, a rare type of fish that is one of the oldest living creatures in the world, dating back to 407-million years ago.
6. The deep cave springtail, a hexapod that is one of the deepest-living animals on earth.

Laughlin said he learned a lot about earth's amazing species while researching the doodle.

"Apparently scientists were able to coax deep cave springtails with a bit of cheese," Laughlin said. "So we're not so different from these little hexapods, after all!"

Laughlin said he hoped his work would inspire a sense of wonder about the earth and its creatures.

"How often does one take a moment to contemplate a tiny critter that lives in the bowels of a cave in Georgia? All life is incredible and worth celebrating," he said.

The reason for this year's Earth Day theme, however, is that so much of that incredible life is disappearing.

"Unfortunately, human beings have irrevocably upset the balance of nature and, as a result, the world is facing the greatest rate of extinction since we lost the dinosaurs more than 60 million years ago," the Earth Day Network wrote. "But unlike the fate of the dinosaurs, the rapid extinction of species in our world today is the result of human activity."

Since Earth Day 2018, some alarming studies have revealed the extent of human destruction. Scientists calculated in October, 2018 that 60 percent of bird, reptile, mammal and fish populations had been killed offt by human activity since 1970. Another study released in February of this year warned that more than 40 percent of insects could go extinct within a few decades and 100 percent could be lost within a century.

Major factors driving extinction are climate change, habitat loss including deforestation, pollution, pesticide use, unsustainable agriculture and poaching, according to the Earth Day Network.

"The good news is that the rate of extinctions can still be slowed, and many of our declining, threatened and endangered species can still recover if we work together now to build a united global movement of consumers, voters, educators, faith leaders, and scientists to demand immediate action," the group said.

Here are the actions they recommended:

1. Educate yourself and others about the rate and causes of extinction.
2. Work towards policies that protect species.
3. Organize a global movement to protect nature.
4. Promote individual actions that protect wildlife like going vegan or gardening and farming without pesticides and herbicides.