Cave-dwelling bugs in Brazil, belonging to the rare Neotrogla genus, set themselves apart in more ways than one, National Geographic reported.

Scientists studying the bugs found that the females possess genitalia structurally and functionally similar to a penis, while the males use a vagina-like opening to distribute their sperm. The researchers published their study in the journal Current Biology.

"It was a surprise for all of us," Rodrigo Ferreira, the study's co-author, said. "This elaborate female penis is completely unique."

It's also quite fit.

Researchers looking at the copulating insects found the couples mated for an average of 50 hours, with one pairing hitting the 73-hour mark. The scientists said the findings could be used to test different hypotheses about sexual selection and the evolution of genitalia. Sarah Eberspacher

Investor Carl Icahn announced Friday that he had stepped down from his advisory role to President Trump. Icahn was counseling the president regarding regulatory reform issues, but he said he was announcing his resignation after a conversation with Trump earlier Friday in which the president "agreed" with his decision.

In a letter to Trump to "confirm" their conversation, Icahn emphasized that he "never had a formal position" with the White House. "I chose to end this arrangement (with your blessing) because I did not want partisan bickering about my role to in any way cloud your administration," Icahn wrote. "I sincerely regret that because of your extremely busy schedule, as well as my own, I have not had the opportunity to spend nearly as much time as I'd hoped on regulatory issues."

Icahn has long been a supporter of Trump's, writer Sarah Kendzior notes. Read Icahn's full letter announcing his resignation below. Kimberly Alters

President Trump fired his chief strategist Stephen Bannon on Friday, and it sure seems like no one in the White House will be torn up over his departure. Shortly after the news broke, Politico published a particularly brutal post-mortem of the Bannon era, with Bannon's now-former colleagues ripping the staunch conservative's tendency to inflame personal tensions:

[Chief of Staff John] Kelly didn't understand what Bannon did, why he had a PR portfolio, why he seemed to cause so much trouble with colleagues and why he was so widely disliked. He asked many questions about Bannon in his early days at the White House and found widespread disdain.

"No one liked him," a senior White House official said. "People didn't know what he did other than stab his colleagues in the back." [Politico]

Bannon was a "disruptive force" who "wouldn't follow process" in the White House, another unnamed White House official said. Nevertheless, he was apparently still "in denial" about his impending ouster, even as rumors of his demise intensified this week.

Read more about Bannon's final days at Politico. Kimberly Alters

If you find it nearly impossible to keep up with the news these days, CNN's Brooke Baldwin has a handy summary of President Trump's past four weeks in office. Only, it takes Baldwin nearly three minutes to read through the entire list of bullet points.

"Let's all just take a moment, just remind you what has happened. Incredibly significant events, one after the other," said Baldwin. "In no particular order, President Trump in the last four weeks has: fires his chief strategist; fires his chief of staff; hires a new one; hires a new communications director; fires him — "

That would be enough for an entire summer, but Baldwin is barely getting started. Watch the entire recital below. Jeva Lange

There is a secret message waiting for readers of this resignation letter, penned by the members of the President's Committee on the Arts and the Humanities:

The first letter of each paragraph spells "RESIST," keen-eyed readers on Twitter discovered. Kal Penn, who sat on the committee, confirmed the Easter egg was intentional.

The entirety of the President's Committee on the Arts and the Humanities resigned Friday over Trump's handling of the protests in Charlottesville, Virginia. "We cannot sit idly by, the way that your West Wing advisers have, without speaking out against your words and actions," the committee wrote. "Ignoring your hateful rhetoric would have made us complicit in your words and actions. We took a patriotic oath to support and defend the constitution of the United States against all enemies, foreign and domestic."

Other eagle-eyed readers might have caught one other awkward thing about the letter: As Soledad O'Brien points out, first lady Melania Trump is the committee's honorary chair. Jeva Lange

Chief strategist Stephen Bannon is out at the White House, but in the words of The New York Times' Maggie Haberman, "Bannon is much more of a problem for the White House staff from the outside than inside it."

That's putting it mildly, at least if you ask people in the orbit of Bannon and Breitbart, the far-right publication Bannon might soon be returning to lead. In the words of Breitbart editor Joel Pollak, after all, this means #WAR.

Here are six dramatic quotes about the coming storm. Jeva Lange

1.

2. Bannon "has a 'killing machine' in Breitbart News." [Axios]

3. Breitbart and Bannon will go "thermonuclear" against the "globalists." [Axios]

4. "Get ready for Bannon the barbarian." [Axios]

5.

6. "If they get rid of Bannon, you know what's gonna happen? The motherlode. If Bannon is removed, there are gonna be divorces, because I know about the mistresses, the sugar babies, the drugs, the pill popping, the orgies. I know everything. If they go after Bannon, the mother of all stories is gonna drop, and we're just gonna destroy marriages, relationships — it's gonna get personal." [Alt-right leader Mike Cernovich via The Daily Beast]

When President Trump began to build his team back in November, he filled the ranks with loyalists, generals, and CEOs who were going to shake up Washington.

But just seven months in, it's the Trump White House that seems to be suffering the most upheaval.

Take this this photo from Jan. 28, which shows Trump surrounded by five members of his team:

Less than six months later, just one — Vice President Mike Pence — still has his job, as political writer Yashar Ali pointed out in a tweet.

As for the rest? Well, let's take a spin around the circle, from left to right: Former White House Chief of Staff Reince Priebus was ousted on July 28, chief strategist Stephen Bannon is out as of Friday, former White House Press Secretary Sean Spicer resigned on July 21, and former National Security Adviser Michael Flynn resigned on Feb. 13.

Pence? How you feeling over there, buddy? Lauren Hansen

On Friday, America learned that Stephen Bannon is packing up his conspiracy board and leaving the White House for good. Bannon's ousting has been rumored since the spring, with President Trump finally conceding his aide's future was uncertain earlier this week. Even Bannon admitted he'd didn't think he'd last more than eight months in Washington. (He was sworn in seven months ago next Tuesday.)

The former (and perhaps returning) head of Breitbart, Bannon has been vehemently opposed by the left since he was appointed. "Homophobia, misogyny, anti-Muslim fearmongering, fat jokes — no matter who you are, Bannon probably thinks you're inferior," The Huffington Post wrote last month.

Here are some of his most telling comments since entering the White House. Jeva Lange

On the chaos on Charlottesville, Virginia: "Just give me more. Tear down more statues. Say the revolution is coming. I can't get enough of it." [The New York Times]

On the far right: "Ethno-nationalism — it's losers. It's a fringe element. I think the media plays it up too much, and we gotta help crush it, you know, uh, help crush it more … These guys are a collection of clowns." [The American Prospect]

(Reportedly) on Jared Kushner: A "cuck" and a "globalist" [The Daily Beast]

On his late-night conversations with former Chief of Staff Reince Priebus:

"We talk a lot, pretty much all day long," Priebus said. "And then we communicate at night —"

"Until we fall asleep," Bannon interjected with a laugh.

Priebus cut in, "Until somebody falls asleep … You fell asleep last night."

"I did," Bannon said.

"I think, like, a quarter to 11," Priebus added.

"I did," Bannon said.

"He became unresponsive," Priebus laughed. [New York]

On why former White House Press Secretary Sean Spicer stopped doing televised press conferences: "Sean got fatter." [The Atlantic]

On his to-do list: TAXES

On his hit list: "[Bannon] has told the president to keep a s--- list on this," one official said. "He wants a running tally of [the Republicans] who want to sink this … Not sure if I'd call it an 'enemies list,' per se, but I wouldn't want to be on it." [The Daily Beast]

On conflict in the White House: "I love a gunfight." [Axios]