Sign up for our daily briefing

Make your busy days simpler with Axios AM/PM. Catch up on what's new and why it matters in just 5 minutes.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Denver news in your inbox

Catch up on the most important stories affecting your hometown with Axios Denver

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Des Moines news in your inbox

Catch up on the most important stories affecting your hometown with Axios Des Moines

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Minneapolis-St. Paul news in your inbox

Catch up on the most important stories affecting your hometown with Axios Twin Cities

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Tampa Bay news in your inbox

Catch up on the most important stories affecting your hometown with Axios Tampa Bay

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Charlotte news in your inbox

Catch up on the most important stories affecting your hometown with Axios Charlotte

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Nick Ut / AP

A new study shows how baleen whales, some of the largest animals ever known to exist on Earth, were able to get so big — and, in evolutionary terms, it's a pretty recent development.

The short answer, per NYT: Thanks to an ice age a few million years ago, whales took advantage of environmental changes to eat. A lot.

It's like going from whales the size of minivans to longer than two school buses. Nick Pyenson, Smithsonian Insitution's National Museum of American History

How it happened: About 4.5 million years ago, ice sheets covered the Northern Hemisphere, causing large amounts of nutrients to pour into coastal waters at specific places and times. That spawned huge populations of baleen whales' favorite foods, plankton and krill. But the explosions of plankton and krill occurred pretty far apart, so only the largest whales could survive the distances between their pig-out sessions.

Bottom line: Add a few million years of evolution to the mix and blue whales are now the largest animals ever to exist on Earth, topping the scales at 380,000 pounds. "It became really advantageous if you're going to move long distances if you're big." Graham Slater, an evolutionary biologist from the University of Chicago, told NYT. In other words, Slater told NYT, if the groups of plankton and krill had been closer together the whales would have grown to a more natural, comfortable size — not the giants we see today.

Other theories: Cheng-Hsiu Tsai, from the National Museum of Nature and Science in Tokyo, told The Atlantic: "It seems to me that people tend to focus on external factors like environmental change and upwelling, but pay little attention to internal factors." For instance, some whales' skulls significantly change as they get older, while others stay the same shape, meaning some whales are genetically incapable of evolving into giant, prey-eating behemoths.

And even Pyenson acknowledged the skepticism: "We have a very spotty fossil record for baleen whales," he said.

Go deeper

Schumer's m(aj)ority checklist

Senate Minority Leader Chuck Schumer. Photo: Tasos Katopodis/Getty Images

Capitalizing on the Georgia runoffs, achieving a 50-50 Senate and launching an impeachment trial are weighty to-dos for getting Joe Biden's administration up and running on Day One.

What to watch: A blend of ceremonies, hearings and legal timelines will come into play on Tuesday and Wednesday so Chuck Schumer can actually claim the Senate majority and propel the new president's agenda.

The dark new reality in Congress

National Guard troops keep watch at security fencing. Photo: Kent Nishimura/Los Angeles Times via Getty Images

This is how bad things are for elected officials and others working in a post-insurrection Congress:

  • Rep. Norma Torres (D-Calif.) said she had a panic attack while grocery shopping back home.
  • Rep. Jim McGovern (D-Mass.) said police may also have to be at his constituent meetings.
  • Rep. Adam Kinzinger (R-Ill.) told a podcaster he brought a gun to his office on Capitol Hill on Jan. 6 because he anticipated trouble with the proceedings that day.
Off the Rails

Episode 3: Descent into madness ... Trump: "Sometimes you need a little crazy"

Photo illustration: Sarah Grillo/Axios. Photos: Tom Williams/CQ-Roll Call, Chip Somodevilla/Getty Images

Beginning on election night 2020 and continuing through his final days in office, Donald Trump unraveled and dragged America with him, to the point that his followers sacked the U.S. Capitol with two weeks left in his term. This Axios series takes you inside the collapse of a president.

Episode 3: The conspiracy goes too far. Trump's outside lawyers plot to seize voting machines and spin theories about communists, spies and computer software.

President Trump was sitting in the Oval Office one day in late November when a call came in from lawyer Sidney Powell. "Ugh, Sidney," he told the staff in the room before he picked up. "She's getting a little crazy, isn't she? She's really gotta tone it down. No one believes this stuff. It's just too much."