How Just One Nasty Winter Forced This Lizard to Evolve

PiccoloNamek, Wikimedia Commons // CC BY-SA 3.0
PiccoloNamek, Wikimedia Commons // CC BY-SA 3.0

Scientists say a single unusually cold season altered the course of history for one American reptile. The green anoles who survived the winter of 2014 were those who could stand the cold—a trait they passed on to their offspring. The researchers published their findings in the journal Science.

The green anole, Anolis carolensis, also known erroneously as the American chameleon, is a vibrant little lizard that makes its home in the southeastern U.S. and Caribbean. Its range extends from Texas as far north as Oklahoma. This is unusual for reptiles, whose cold-blooded bodies typically restrict them to balmier climates.

Map of the geographic range of the green anole.
Graphic by Julie McMahon

To find out how the anoles were managing it, Shane Campbell-Staton, now of the University of Illinois, paid visits to five scattered populations in 2013. He collected samples and a few live lizards from each group to test their DNA, gene expression, and tolerance for low temperatures.

He found a fair amount of variation between lizard communities. Those in Oklahoma had clearly evolved to handle the weather there, while specimens from further south couldn't take the cold.

Satisfied with his data and findings, Campbell-Staton prepared to wrap up the project.

Then winter came. You may remember the winter of 2014, when a polar vortex created record-breaking low temperatures and wrought terrible storms across the U.S., including in anole territory. Campbell-Staton couldn't help but wonder how—or if—the cold-intolerant lizards had survived.

The next spring and summer, he and his colleagues made another circuit through anole country and collected more samples. The Oklahoma families hadn't fared too poorly. But down south, things had clearly changed. The genetic code of Texan lizards looked more like their northern cousins, and individuals were far better at handling a chill. 

The research team realized that the brutal winter had killed off most of the cold-intolerant lizards, leaving behind only those who happened to have genes more like their northern cousins'. Those lizards reproduced, creating new generations of cold-ready individuals.

But that's not necessarily a good thing.

"One might think, 'Oh, they responded! They're better now,'" Campbell-Staton said in a statement. "But selection always comes at a cost, which is death, basically. It may be that the animals that did not survive this storm had the genetic variants to survive a heat wave, or a drought, or some other extreme event. And now those lineages are essentially gone." 

Is There An International Standard Governing Scientific Naming Conventions?

iStock/Grafissimo
iStock/Grafissimo

Jelle Zijlstra:

There are lots of different systems of scientific names with different conventions or rules governing them: chemicals, genes, stars, archeological cultures, and so on. But the one I'm familiar with is the naming system for animals.

The modern naming system for animals derives from the works of the 18th-century Swedish naturalist Carl von Linné (Latinized to Carolus Linnaeus). Linnaeus introduced the system of binominal nomenclature, where animals have names composed of two parts, like Homo sapiens. Linnaeus wrote in Latin and most his names were of Latin origin, although a few were derived from Greek, like Rhinoceros for rhinos, or from other languages, like Sus babyrussa for the babirusa (from Malay).

Other people also started using Linnaeus's system, and a system of rules was developed and eventually codified into what is now called the International Code of Zoological Nomenclature (ICZN). In this case, therefore, there is indeed an international standard governing naming conventions. However, it does not put very strict requirements on the derivation of names: they are merely required to be in the Latin alphabet.

In practice a lot of well-known scientific names are derived from Greek. This is especially true for genus names: Tyrannosaurus, Macropus (kangaroos), Drosophila (fruit flies), Caenorhabditis (nematode worms), Peromyscus (deermice), and so on. Species names are more likely to be derived from Latin (e.g., T. rex, C. elegans, P. maniculatus, but Drosophila melanogaster is Greek again).

One interesting pattern I've noticed in mammals is that even when Linnaeus named the first genus in a group by a Latin name, usually most later names for related genera use Greek roots instead. For example, Linnaeus gave the name Mus to mice, and that is still the genus name for the house mouse, but most related genera use compounds of the Greek-derived root -mys (from μῦς), which also means "mouse." Similarly, bats for Linnaeus were Vespertilio, but there are many more compounds of the Greek root -nycteris (νυκτερίς); pigs are Sus, but compounds usually use Greek -choerus (χοῖρος) or -hys/-hyus (ὗς); weasels are Mustela but compounds usually use -gale or -galea (γαλέη); horses are Equus but compounds use -hippus (ἵππος).

This post originally appeared on Quora. Click here to view.

A Rare Blue Lobster Ended Up in a Cape Cod Restaurant

Richard wood, Flickr // CC BY 2.0
Richard wood, Flickr // CC BY 2.0

Lobsters have precious few defenses when it comes to being tossed in a vat of boiling water or on a grill and turned into dinner. They have not yet evolved into not being delicious. But sometimes, one lucky lobster can defy the odds and escape their sentence by virtue of a genetic defect that turns them blue.

According to MassLive, one such lobster has been given a reprieve at Arnold's Lobster & Clam Bar in Cape Cod, Massachusetts. Named "Baby Blue," the crustacean arrived at the restaurant from the Atlantic and was immediately singled out for its distinctive appearance.

Blue lobsters are a statistical abnormality. It's estimated only one in every two million carry the defect that creates an excessive amount of protein that results in the color. A lobsterman named Wayne Nickerson caught one in Cape Cod in 2016. He also reported catching one in 1990. Greg Ward of Rye, New Hampshire caught one near the New Hampshire and Maine border in 2017.

Lobsters can show up in a variety of colors, including orange, yellow, a mixture of orange and black, white, and even take on a two-toned appearance, with the colors split down the middle. Blue is the most common, relatively speaking. A white (albino) specimen happens in only one out of 100 million lobsters. The majority have shells with yellow, blue, and red layers and appear brown until cooked, at which point the proteins in the shell fall off to reveal the red coloring.

It's an unofficial tradition that blue lobsters aren't served up to curious customers. Instead, they're typically donated to local aquariums. Nathan Nickerson, owner Arnold's, said he plans on doing the same.

[h/t MassLive]

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