1 . Frozen in time, a 125-million-year-old mammal attacking a dinosaur. A 39-million-year-old whale, the heaviest animal that ever lived. The oldest known jellyfish, from 505 million years ago. Paleontology (古生物学) produces newsworthy discoveries.

Fossils (化石), moreover, provide direct evidence for the long history of life, allowing paleontologists to test hypotheses (假设) about evolution with data only they provide. They allow investigation of present and past life on Earth. Flows of biological diversity, appearances of new life forms and the extinctions of long existing ones, would go undiscovered without these efforts. But the headlines over exciting new fossils greatly underestimate the true importance of paleontology. Its real significance lies in how such discoveries brighten the grand history of life on Earth. From its beginnings, more than three billion years ago, to the present day, fossils record how life adapted or disappeared in the face of major environmental challenges.

Paleontologists provide us with a unique vantage on modern climate change. They play an essential role in interpreting ancient environments, in reconstructing ancient oceans, continents and climates. Fossils provide key limitation on the climate models that are essential for predicting future climate change. And the fossil record gives important insights into how life will respond to predicted future climate conditions, because these have occurred before in Earth’s history.

In addition, paleontology has provided a fundamental contribution to human thought: the reality of species extinction and thus of a world that has dramatically changed over time. In documenting the history of life, paleontologists recognized that many extinction episodes could occur suddenly, such as the event 66 million years ago that ended the dinosaurs. The search for the causes of past mass extinctions started pioneering studies from across the scientific spectrum (科学界), focusing on potential future threats to humanity.

Not only do paleontologists know what happens to life when things go bad, they also know how long it takes for ecosystems and biodiversity to recover from these disasters, which can take far longer than modern humans have existed.

Paleontologists thus provide a unique perspective on the nature and future long-term ecological impact of the current human-produced biodiversity crisis, the so-called Sixth Extinction, and therefore the importance of protecting modern biodiversity. The very concept of a Sixth Extinction would not exist without paleontologists documenting the first five.

Paleontologists know that understanding life’s past is critical to anticipating and adapting to life’s and humanity’s future. Paleontology is important because it brings its unique and critical perspective to current challenges in climate change, biodiversity loss and the environment. Paleontologists can predict the future because they know the past.

2 . While DNA from animal bones or teeth can cast light on an individual species, environmental DNA enabled scientists to build a picture of a whole ecosystem.

A core of ice age sediment (沉积物) from northern Greenland has yielded the world’s oldest sequences of DNA. The 2 million-year-old DNA samples revealed the now largely lifeless polar region was once home to rich plant and animal life — including elephant-like mammals known as mastodons (乳齿象), reindeer, hares, lemmings, geese, birch trees and poplars, according to new research published in the journal Nature on Wednesday.

The finding is the work of scientists in Denmark who were able to detect and restore environmental DNA — genetic material drop into the environment by all living organisms — in tiny amounts of sediment taken from the Copenhagen Formation, in the mouth of a strait in the Arctic Ocean in Greenland’s northernmost point, during a 2006 expedition.

They then compared the DNA pieces with libraries of DNA collected from both extinct and living animals, plants and microorganisms. The genetic material revealed dozens of other plants and creatures that had not been previously detected at the site based on what’s known from fossils and pollen records.

“The first thing that blew our mind when we’re looking at this data is obviously this mastodon and the presence of it that far north, which is quite far north of what we knew as its natural range,” said study co-author Mikkel Pedersen.

The mix of temperate (温带) and Arctic trees and animals suggested a previously unknown type of ecosystem that has no modern equivalent — one that could act as a genetic road map for how different species might adapt to a warmer climate, the researchers found.

Love Dalen, a professor at the Centre for Palaeogenetics at Stockholm University, said the finding “pushed the envelope” for the field of ancient DNA. “Also, the findings that several temperate species (such as relatives of spruce and mastodon) lived at such high latitudes are exceptionally interesting,” he added.

Further study of environmental DNA from this time period could help scientists understand how various organisms might adapt to climate change. “It’s a climate that we expect to face on Earth due to global warming and it gives us some idea of how nature will respond to increasing temperatures,” he explained.