Nothing in Biology Makes Sense: Making sense of evolving invaders

Image via Nothing in Biology Makes Sense.

This week at the collaborative science blog Nothing in Biology Makes Sense, guest contributor Kathryn Turner discusses how evolutionary processes determine whether an introduced species becomes an invasive species.

First, most obviously, how is it that a species is able to come into a new environment that it is not adapted to, surrounded by new environmental conditions and foreign biological interactions, and thrive? Thrive so exaggeratedly, that it can out-compete and displace species which have been there for millennia, adapting precisely to those environmental conditions and biological interactions? How can an individual survive to propagate a population? How can any species accomplish this? Second, less obviously: why can’t more species do it? Humans transport animals and seeds (and spores and larvae, etc, etc) around all the time, but only 10% establish self-sustaining populations, and only 1% spread to new habitats, becoming potentially invasive; this is known as the ‘tens rule’ (Williamson 1993) – a funny ‘rule of thumb’ for which I could never quite figure out the math.

For the answers, or at least some ideas about possible answers, go read the whole thing.◼

Evolutionary psychology: A dialogue

Photo by C Simmons.

A Biologist went down to the coffee shop one day, because the walk out to the edge of the University campus provided some brief respite from the laboratory. Along the way the Biologist encountered an Evolutionary Psychologist, who was also going to the coffee shop, and they fell to walking together.

As they entered the coffee shop, they found it crowded with undergraduates, for it was almost Finals Week. Accordingly, they joined the long queue of prospective customers waiting to place an order. Said the Evolutionary Psychologist to the Biologist, "My dear colleague, do you not see this crowd of fertile young people as I do, engaged in a dance of mate selection and competiton that predates our ancestors' descent from the trees?"

And the Biologist replied, "I don't believe that our ancestors had access to steamed milk and espresso. Or free wi-fi."

"You are being amusingly obtuse!" chortled the Evolutionary Psychologist. "The environment may have changed somewhat since the days of our Darwinian origins, I will allow, but ova remain much dearer than sperm cells."

"That much is certainly true," said the Biologist. "But I am not sure how much it matters to the coffee-shop flirtations of undergraduates, almost none of which will result in procreative intercourse."

"Ah," said the Evolutionary Psychologist, "Perhaps this is a subject wherein my own field has surpassed the expertise of yours, my dear colleague. For instance, we have recently discovered [PDF] that men are more attracted to unintelligent, inattentive women—precisely what one would expect if men have been naturally selected to seek out easy opportunities for impregnation. And this search is doubtless underway all around us at this very moment."

"That is a remarkable and possibly misogynistic hypothesis," said the Biologist. "I am most curious to know how it was tested."

Awkward!

Via Bora Zivkovic: Today over a thousand people gathered in Newton, North Carolina, to protest reprehensible anti-gay remarks made by a local pastor. Which, good for them! But when you stage a protest against proposing to basically put gay people in concentration camps (or, let's be fair: dude actually proposed just one big concentration camp), you've got to expect that there will be some counter-protesters. And you never know who you'll meet counter-protesting a protest against a proposed homocaust:

Earlier in the day, one counter protester was caught off guard when a peacekeeper working with protest organizers to keep participants separated from counter protesters saw someone he recognized. The peacekeeper told [this reporter] that one of the counter protesters, a man in his mid-20s or early-30s, once hit on him at a local adult bookstore. The counter protester denied the accusation while holding a sign that condemned gays. The counter protester left the protest early. [Emphasis added.]

Way to break free of the stereotypes, counter protester dude! How does that line go? ... Then they came for the lesbians and the queers, and I enthusiastically endorsed that idea, because no way am I into that sort of thing regardless of what you heard and anyway even if I was, speaking hypothetically, it was just some sinful experimentation in college and then many, many times again after college.◼

Science online, Proustian bargain edition

Fire ant: "Sharp, sudden, mildly alarming. Like walking across a shag carpet and reaching for the light switch." Photo by AJC1.

• Have you signed the White House petition for open access? WHY HAVEN'T YOU SIGNED THIS PETITION? Go sign this petition.
• "... not easily translated or generalisable to the normal population" The case of a man who doesn't forget anything.
• "A rare, piercing, elevated sort of pain." Insect stings, ranked by painfulness and described in poetic detail.
• God (or whoever) help us all. Who let David Brooks read about evolutionary psychology?
• Or is it just ... resting? Is there an adaptive function for sleep?
• Beautiful! But mostly from a distance. Underground constellations of glowing carnivorous cave-worms.
• In mice. Transplanted nerve cells relieve chronic pain.
• Pretty sure I can't make the call in 50 milliseconds, without clothing or hair cues. The details of that study on "gaydar" are stranger than you might think.
• In mice! Eating on a schedule, rather than snacking all day, reduces weight gain.
• Nothing fishy about it. A fossil fish with a backbone segmented into neck, back, pelvic, and tail bones suggests that segmented backbones first evolved for swimming, not walking.
• Back to the future. To build radiation-hard computers for outer space, NASA is devloping new miniaturized vaccum tubes.

◼

Carlos DeLuna

Carlos DeLuna, wrongfully executed by the State of Texas in 1989. Photo via Columbia Human Rights Law Review.

I've been trying to come up with something profound to say about this ever since I first saw it on Slog, but I don't know what more to add to the statement: in 1989, the State of Texas executed Carlos DeLuna for a murder he very clearly didn't commit.

The Columbia Human Rights Law Review has devoted an entire issue—available online, in completion, with exhaustively detailed supporting information—to an investigative report on DeLuna's case. At the Guardian, Ed Pilkington picks out the most important details.

Carlos DeLuna was arrested, aged 20, on 4 February 1983 for the brutal murder of a young woman, Wanda Lopez. She had been stabbed once through the left breast with an 8in lock-blade buck knife which had cut an artery causing her to bleed to death.

From the moment of his arrest until the day of his death by lethal injection six years later, DeLuna consistently protested he was innocent. He went further – he said that though he hadn't committed the murder, he knew who had. He even named the culprit: a notoriously violent criminal called Carlos Hernandez.

The two Carloses were not just namesakes – or tocayos in Spanish, as referenced in the title of the Columbia book. They were the same height and weight, and looked so alike that they were sometimes mistaken for twins. When Carlos Hernandez's lawyer saw pictures of the two men, he confused one for the other, as did DeLuna's sister Rose.

What happened was: Carlos DeLuna was unfortunate enough to witness Carlos Hernandez attacking Wanda Lopez, and ran off. The police found him near the crime scene, hiding under a truck, and almost immediately confirmed that he matched witness descriptions of Hernandez. Having a suspect, the police barely conducted any further investigation into the murder. More from Pilkington:

Detectives failed to carry out or bungled basic forensic procedures that might have revealed information about the killer. No blood samples were collected and tested for the culprit's blood type.

Fingerprinting was so badly handled that no useable fingerprints were taken. None of the items found on the floor of the Shamrock – a cigarette stub, chewing gum, a button, comb and beer cans – were forensically examined for saliva or blood.

There was no scraping of the victim's fingernails for traces of the attacker's skin. When Liebman and his students [the authors of the investigative report] studied digitally enhanced copies of crime scene photographs, they were amazed to find the footprint from a man's shoe imprinted in a pool of Lopez's blood on the floor – yet no effort was made to measure it.

People interviewed for the investigation even confirmed that Hernandez repeatedly confessed to the murder. But it was Carlos DeLuna who was executed by lethal injection on the 8th of December, 1989.

The U.S. legal system is, at the most fundamental level, people. People can get things wrong. When the legal system is able to punish people by killing them, that means that the legal system can kill the wrong person. And now, if you need an example of someone who was wrongfully put to death in our country, you have a name: Carlos DeLuna, sacrificed to our society's insistence that we should be able to punish death with death.◼

Ecological complexity breeds evolutionary complication

Photo by futureatlas.

Cross-posted from Nothing in Biology Makes Sense!

It is a truth universally acknowledged in evolutionary biology, that one species interacting with another species, must be having some effect on that other species' evolution.

Actually, that's not really true. Biologists generally agree that predators, prey, parasites, and competitors can exert natural selection on the other species they encounter, but we're still not sure how much those interactions matter over millions of years of evolutionary history.

On the one hand, groups of species that are engaged in tight coevolutionary relationships are also very diverse, which could mean that coevolution causes diversity. But it could be that the other way around: diversity could create coevolutionary specificity, if larger groups of closely-related species are forced into narower interactions to avoid competing with each other.

Part of the problem is that it's hard to study a species evolving over time without interacting with any other species—how can we identify the effect of coevolution if we can't see what happens in its absence? If only we could force some critters to evolve with and without other critters, and compare the results after many generations ...

Oh, wait. That is totally possible. And the results have just been published.

Tell the White House: Make government-funded research open-access

As J.B.S. Haldane put it, "I think ... that the public has a right to know what is going on inside the laboratories, for some of which it pays." He was referring to the need for scientists to explain their work in popular media—which, amen, brother Jack!—but the point holds with regard to access to original scientific articles, too.

It doesn't make much sense that U.S. citizens, whose taxes fund most of the basic science in this country, are then expected to pay upwards of $50 for a single PDF copy of a journal article presenting government-funded research results. The National Institutes of Health already requires that research it funds be archived online and accessible to the general public free of charge—why not expand that to all government-funded research? And hey, there's a way to suggest exactly that out to the man in charge: a petition on WhiteHouse.gov.

We believe in the power of the Internet to foster innovation, research, and education. Requiring the published results of taxpayer-funded research to be posted on the Internet in human and machine readable form would provide access to patients and caregivers, students and their teachers, researchers, entrepreneurs, and other taxpayers who paid for the research. Expanding access would speed the research process and increase the return on our investment in scientific research.

The highly successful Public Access Policy of the National Institutes of Health proves that this can be done without disrupting the research process, and we urge President Obama to act now to implement open access policies for all federal agencies that fund scientific research.

It needs 25,000 virtual signatures within 30 days before it'll get any meaningful attention, so sign this thing and then start badgering all your online "friends" about it, why don't you? Especially the jerks who keep filling your update stream with branded product promotions and/or time-sucking adorable cat videos and/or news about how they've just spent real money for a virtual cow—post this directly on their "walls," if those are even still a thing, with or without a witty and/or pleading comment appended.

I mean, it's Monday morning; it's not like you're going to get do anything else for the benefit of humanity in the next minute or two, you slacker.◼