Stories tagged Biological Populations Change Over Time
Man vs. mammoth: Is a face-off like this in our future...again?
Courtesy redskunkScientists are another step closer to making Jurassic Park a reality. Well, not quite Jurassic Park, but certainly Pleistocene Park.
Researchers at Pennsylvania State University have decoded 80 percent of the DNA for the woolly mammoth, an elephant ancestor that went extinct about 10,000 years ago. The results of their study appear in the journal Nature.
The DNA was extracted from actual mammoth hair found preserved in the permafrost of Siberia. Hair encapsulates DNA, providing a purer source of the genetic material than that found in fossil bones that are vulnerable to contamination by bacteria and other creatures involved in decomposition. We covered this in a previous post.
About six million years of evolution separate the wooly mammoth from its modern descendents the Indian and African elephants. And so far they appear genetically to be very similar, although a complete assessment of differences won’t be available until the complete genomes of mammoths and modern elephants are mapped. The data sets for each is comprised of about 4 billion DNA bases.
But even then you don’t have to worry about rogue mammoths running amok on the interstates (have you ever hit a moose? Multiply that experience by about 15). Science is still decades away from cloning an actual specimen – or even a hybrid with a living elephant - from the genetic material. The technology just isn’t there yet. But that’s not the only thing in the way.
"It could be done,” said co-author Stephan Schuster, a biochemistry professor at Penn State. “The question is, just because we might be able to do it one day, should we do it?"
Sounds familiar doesn’t it? The same question was posed by one of the characters in Michael Crichton's book Jurassic Park just before things got really hairy.
SOURCES and LINKS
Penn State's mammoth research page
Live Science story
Previous Buzz story on mammoth cloning
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I have a tiny black belt: And a condo in Cabo. I'll totally take you there sometime, babe.
Courtesy JunglecatAustralian ecologists have recently been observed soiling themselves and drooling over lying crabs.
Honestly, people. Lying about crabs, now that might be something worth getting excited over… But this? Whatever.
What the ecologists have observed, to be precise, are fiddler crabs that are “dishonest” about their own physical prowess, acting as though they are stronger fighters than they actually are.
Fiddler crabs have two pinching claws, but, in males, one of the claws grows to be much, much larger than the other one. This larger, stronger claw is used to attract mates, and to fight off male competitors. If a crab’s fighting claw is ripped off, a new one will grow back. The researchers noticed, however, that some male crabs were growing new claws that were as large as their old claws, but were also significantly weaker, and lacking serrated “teeth.” The new claws were “cheaper” for the crabs to grow (that is, they required less energy and food from the crab), and other crabs were unable to tell them apart from “real” claws.
It’s like the crabs had figured out that they could stick up a bank with a fake gun—the weapon is cheaper, and ultimately harmless, but it looks like its dangerous.
The scientists are excited because it’s rare that they’re able to study animal “dishonesty” so fully—here they can measure a crab’s claw size and strength, and the crab’s ability to keep itself from being pulled out of its burrow, and they can observe how successful individual crabs are in acquiring a mate.
To this, I say, “Whatev.” I’m an expert at acting tougher than I really am, and Australian ecologists act like I don’t even exist. Despite my weak limbs, my tactic of scuttling around sideways and circling my opponents while waving my hands in the air always, I say always, works. They don’t know what hit them (and it certainly wasn’t me). And then it’s just me and the ladies.
(Although the ladies are usually always kind of freaked out by the scuttling thing too. But the first part of the strategy remains sound.)
The world’s oldest bachelor
in Life Science, Heredity, Biological Populations Change Over Time, and Human Organism
Sorry, kid, you're barking up the wrong tree: Otzi ain't yer dad. And, whoever you pops is, I doubt you dressing up like that will make him love you any more.
Courtesy japi14I think this came out a couple weeks ago, so maybe it’s old news to y’all—although, technically, I suppose it’s old news to everyone.
Otzi (Remember? Otzi the Iceman?) died alone.
No, wait, that didn’t come out right. Otzi the Iceman didn’t die alone—he probably died surrounded by his killers, after they had shot him in the chest with an arrow, as one of them likely finished him off by clubbing his skull in. What I meant was Otzi died alone in the genetic sense, with no one to carry on his legacy. (His legacy of being a five-foot-five total badass.)
It turns out that Otzi, in spite of his many, many admirable qualities, probably had no children. Or, at least, that Otzi’s lineage has died out since the time of his death.
Previous studies had suggested that Otzi may have had living descendants somewhere in Europe, but recent genetic research has shown that this is unlikely. Italian and British scientists have analyzed the iceman’s mitochondrial DNA—which is passed on solely matrilineally—and the results seem to indicate that Otzi was part of a heretofore unknown genetic line, and one that has probably gone extinct.
Oh, fudge. And here I was, still holding out hope.
What gives, caveladies? What was so bad about the little iceman? Too tough, I’m guessing. The same reason women could never get truly close to the Fonz.
*It occurs to me that Otzi could have had a child himself, and his mitochondrial DNA wouldn’t have been passed on. Maybe he just had equally intimidating sisters.
Yeah, sort of scary: I mean, look what it's doing to the concept of public art! Oh, wait, this is the Mothman.
Courtesy billy liarHey, y’all, it’s time for a brand new Science Buzz feature: Is that, like… scary? On Is that, like… scary? we’ll be posing the question “Is that, like… scary?” with regards to one of the many, like, scary things out there. Out there in the world.
Because this is a brand new, first of its kind sort of thing, all y’all Buzzketeers should feel lucky: this could be a valuable experience. Not now, certainly, but I think it’s pretty likely that the cash value of this moment in history will be skyrocketing before too long. Heck, if you play your cards right, time the market, etc, you could pay your way through college just by telling people about this. So get on the boat, and ask yourself, “Is that, like… scary?”
I don’t want to throw you guys into the deep end just yet, though—you have to crawl before you can walk, and you have to have the right clothing on before you can crawl, so let’s ease ourselves into this.
So… flesh-eating bacteria—Is that, like… scary? Duh, yes, it’s very like scary.
Feral dog packs—Is that, like… scary? Well, it’s sort of like scary.
Seasonal allergies—Is that, like… scary? No, dude, that’s not like scary.
This thing—Is that, like… scary? Uh, yeah, that’s a lot like scary.
Are you starting to get a feel for things here? Good. We can get to the meat now: vampire moths.
Are vampire moths, like… scary? Maybe, maybe. We’d better take a closer look, courtesy of National Geographic.
What we’ve got is a Siberian moth that, like the common vampire, does indeed suck blood. It uses its “hook-and-barb-lined tongue” to drill through skin and start slurping. And while vampire moths aren’t new, blood-drinking in this Siberian population actually does seem to be a recent adaptation—aside from the vampire thing, only slight differences in wing patterns distinguish the blood sucker from its vegetarian cousins, who use their pokey little tongues for jabbing fruit. But these moths, when offered a hand by the scientists, dug right in. So, at some not-so-long-ago point, the little apple-biters got the idea (in an evolutionary way) to just start drinking blood. Cuz it’s so good.
I think that makes them a little more, like, scary. If a little lamb passed up a handful of nutritious, green lamb food in favor of taking a chunk out of your wrist, it would be kind of creepy, wouldn’t it? That’s sort of how I feel about vampire moths.
It turns out that that only the male moths drink blood. Scientists aren’t totally sure why, but they think the blood allows the males to give female moths a gift of salt during copulation. Apparently lady moths are into salt. This specific salt-gathering strategy could have evolved from behaviors like drinking tears (that’s, like… creepy), feeding on dung (that’s, like… funny), and dipping into pus-filled wounds (that’s, like… getting closer to scary).
The next step for the researchers will be to compare the DNA of the vampires to their vegetarian cousins, to see how different they are, and how long it could have been since the species split apart.
So what do you think? Is that, like… scary?
Honeycrisp apples
in Diversity of Organisms and Biological Populations Change Over Time
Malus domestica 'Honeycrisp'
Courtesy Art Oglesby
Honeycrisp, my favorite apple
Around the end of September I eagerly visit an apple orchard to stock up on Honeycrisp apples. I first experienced Honeycrisp apples back when they were first released in 1991 because I lived next door to Jack Kelly and what is now part of Apple Jack Orchards. I was impressed by the "explosively crisp" snap as you bite into the apple and its sweet, juicy flavor that also has a hint of tartness. Here is a quote about the Honeycrisp apple from the University of Minnesota Extension:
Honeycrisp fruit is characterized by an exceptionally crisp and juicy texture. Its flesh is cream colored and coarse. The flavor is sub-acid and ranges from mild and well-balanced to strongly aromatic, depending on the degree of maturity. It has consistently ranked as one of the highest quality apples in the University of Minnesota sensory evaluations.
The Honeycrisp story is remarkable
I first read the amazing story about how the Honeycrisp was developed in the City Pages. James J. Luby and David S. Bedford, working within the Department of Horticultural Science University of Minnesota, have given a big boost to Minnesota's apple growers and the horticulture department.
Bedford calls it a "lifesaver." According to the university's office of technology commercialization, Honeycrisp has generated $6.3 million for the institution, placing it among the school's top five most lucrative inventions. (The U receives $1.35 a tree and splits royalty income in thirds, with one portion going to the inventors, another to the college and department where the faculty work, and the third into a general research fund.)
How the Honeycrisp apple is produced
Apple breeder David Bedford tastes between 500 and 600 apples every day. Bedford is trying to find the genetic gems from among the nearly 20,000 trees in the horticulture department's orchards. Only 15 or so have the "wow" that allows their genetics to advance to the next round. Hand pollinating select blossoms and using wax bags to prevent any stray pollination, produces the next generation of seeds. The ancestors of the Honeycrisp were in the crop of 1960. A bad freeze almost eliminated the genetic line in 1980. When the parent trees were killed by a 1 in 50 yr. freeze, the offspring were classified as unacceptable. Bedford decided to let them have a chance, and
A few years later, when the clones began bearing fruit, Bedford was shocked by the apples' crispness and juiciness, which reminded him of an Asian pear. "The thing I remember was that the texture was so unusual, I wasn't sure if it was good or bad," he says.
Read more about the Honeycrisp saga
The complete story is fascinating. You can read more by clicking the City Pages link. Probably the best description of the Honeycrisp apple sage is told at MinnesotaHarvest.net. An addendum within this webpage added this surprising quote:
Records and public releases from the University of Minnesota from 1991 to the present have identified the parentage of Honeycrisp as the cross 'Macoun' x 'Honeygold'. But recently completed DNA testing has determined that neither Macoun nor Honeygold are parents of Honeycrisp.
The testing determined for certain that Keepsake, another apple from the University of Minnesota's apple breeding program that was released in 1978, is one of the parents. But, despite extensive searching, the other parent has not been identified. There is no DNA match among any of the varieties that are thought to be possible parents.
The University's Research Center routinely crosses and plants thousands of seeds annually, moving them and the resulting seedling trees from place to place over a period of years, so there are multiple points where a mix-up could take place.
Lemur leaf frog: Frogs are threatened by a fungus that can kill up to 90 percent of amphibians in a stream and lead to decimation of the rest of an ecosystem.
Courtesy Scott Connelly/UGAResearchers studying an amphibian-killing chytrid fungus (Batrachochytrium dendrobatidis) spreading through the streams of Central America, are using the opportunity to investigate the effects that the loss of frogs have on a stream’s overall ecology.
Chyrtid fungus has been spreading southeast through Central America destroying amphibian populations along the way. Scientists from the University of Georgia in Athens set up two separate study areas – one in a stream that had been invaded by the fungus, and another unaffected stream that was in the path of the spreading outbreak.
What they discovered is how important tadpoles are in keeping a stream’s ecology in balance. The tadpoles, it seems, stir up quiet pockets of the stream as they hunt for food, an activity that keeps sediment suspended in the water from settling to the bottom. This allows more sunlight to reach the algae growing there which, in turn, processes it into an energy source that is the base of the stream’s food chain.
“Many things that live in the stream depend on algae as a base food resource,” said lead author Scott Connelly, a doctoral student from the UGA Odum School of Ecology. “And we found that the system was more productive when the tadpoles were there.”
Although the algae increased by as much as 250 percent in some cases, the lack of agitation from the decimated tadpole population allowed more sediment to cover the bottom and stifle the algae’s processing of sunlight and nutrients into a food source for the rest of the stream’s fauna.
The scientists have been able to save infected frogs in captivity by applying a fungicide, but so far they have been unable to restore ecosystems damaged by the fungus because a widespread application of the fungicide would also kill any beneficial fungi.
The results of the study appeared last week in the online version of the journal Ecosystems.
UGA press release
Story on ScienceDaily
More on the amphibian extinction crisis
All about tadpoles
i can't wait to get out of high school so i can go to school to be a pharmacist
What on earth am I supposed to do with this thing?: A pterosaur considers his situation.
Courtesy John ConwayPaleontology, y’all, paleontology. We’ve got these bones, these fossilized bones. And they’re nice bones, don’t get me wrong, but sometimes they leave a little to be desired when it comes to reconstructing the nitty gritty and sticky details of what living dinosaurs (and pterosaurs, ichthyosaurs, mosasaurs, therapsids, etc) were actually like. A skeleton can give us a good idea of a creature’s general shape; it can show where the muscles went (more or less), what sort of food it ate, how it probably moved—that kind of thing. But how did they behave? What color were they? Exactly how strong were they? There are a whole slew of questions that get to be a little tricky.
So, how do paleontologists go about answering these questions? They get creative, they study all the tiniest details of the fossils, and, sometimes, they look to living animals for analogy—that is to say, if an animal alive today that lives in a similar environment to that of an extinct animal, and has a similar body type to the extinct animal, you might be able to base knowledge of the extinct animal on what you know of the living animal.
It’s a valuable avenue of study, but dinosaurs and their ilk were pretty different, after all, so how far do you think can we take analogies to living creatures?
And now on to the news item.
A Japanese researcher has opened up his sass-box and gotten all up in the faces of paleontologists around the world. Pterosaur specialist paleontologists are particularly fired up, and they’re a dangerous bunch. “Peer review” among pterosaur specialists, as I understand it, involves switchblades, and the majority of the community sports eye-patches.
This scientist, Katsufumi Sato of the University of Tokyo, is saying that pterosaurs (all of the huge extinct flying reptiles) probably maybe couldn’t actually, you know… fly.
Oh no you di’en’t!
Says Sato: Yes, yes I did. Specifically, what the scientist did was place accelerometers on the wings of a couple dozen sea birds on the Crozet Islands. The accelerometers measured, more or less, the flapping force and speed of the birds’ wings.
Among the birds studied were wandering albatrosses, which have the largest wingspans of any living birds. Large seabirds like this have often been used as analogies for pterosaurs for their somewhat similar body shapes. Many pterosaurs probably lived in a similar habitat to modern seabirds as well.
Albatrosses fly by riding shifting wind currents, and by flapping their wings when the wind isn’t suitable, or is absent entirely. Sato found that the seabirds he studied have two flapping speeds, a faster speed for taking off, and a slower speed for staying aloft in the absence of wind. He also noticed that, as this flapping speed is limited by the birds’ strength, it decreases in heavier birds with longer wings.
According to the calculations Sato based off of this data, birds (or pterosaurs) weighing more than about 90 pounds would be unable to fly without using wind currents—they simply wouldn’t be able to flap their wings fast enough to stay in the air. There were certainly pterosaurs that size and much smaller, but a lot of flying reptiles were probably a great deal larger than that (a very conservative estimate for the quetzalcoatlus, for example, would have it weighing around 220 pounds).
The article I read on this research doesn’t get into Sato’s hypothesis much more than that, but I’d assume that this means that larger pterosaurs would then also be unable to take off from anywhere other than, say, a cliff face. I wonder if the implication is also that they wouldn’t be doing any flying at all; that medium to large pterosaurs wouldn’t even be gliding on wind currents because, at some point, they’d need to gain some altitude on their own steam.
But, whatever the specifics, them’s fightin’ words, and pterosaur specialists the world over are no doubt sharpening their boot-spikes, and wrapping their fists in chains.
Is it a valid analogy? Maaaaybeeee… But I’m betting against it. There have been some interesting theories lately about how the largest of the pterosaurs may not have flown as much as we used to think, but they don’t imply that they couldn’t fly at all. In fact, the study I’m thinking of would further distance pterosaurs from large seabirds in terms of behavior and their ecological niches (making any analogies a little less apt).
Other scientists argue that in addition to anatomical and physiological differences that should be considered, the atmosphere of the Mesozoic was, on the whole, somewhat denser, and had higher concentrations of oxygen—factors that would have allowed flight for larger, heavier animals. Actually, I recommend checking out the discussion following the article. There are a bunch of explanations of how pterosaurs could have flown, despite what this study suggests. But, if you do go, bring your knives—they’re an angry bunch.
What, I can only lock this from the outside?: Scientists have observed behavior in ants in Brazil where a small group of ants sacrifice themselves each night for the good of the colony by covering the colony entrance from the outside, leaving them outside at night exposed to all sorts of natural forc
Courtesy Fir0002How do you secure your home at night? With a deadbolt lock? Switching on some high-tech electronic security system? A pit bulls (without lipstick)?
Whatever you do, it's probably not as problematic as what a few ants do each night in Brazil. Researchers have observed that one to eight ants from a colony each night sacrifice themselves for the well being of the colony. They stay above ground pushing sand over the entrance to the colony to protect their peers from predators during the night. Because they're left outside, they most often die in the night, either from freezing in chilly temperatures, getting blown away in high winds or being a midnight snack for a predator.
A typical ant colony in Brazil can number over 100,000, so the few ants lost each night for security is not a huge mathematical loss. How exactly the night workers are selected isn't known for sure, but researchers think they're probably older ants who are approaching the end of their natural life span.
Six-toed cats can remain at Hemingway museum
in Life Science, Diversity of Organisms, and Biological Populations Change Over Time
Hemingway cat: One of Snowball's many descendants takes it easy behind the Hemingway Home and Museum in Key West, Florida.
Courtesy Mark RyanThe fifty or so cats living around the former estate of author Ernest Hemingway in Key West, Florida, have been granted a reprieve from the US Department of Agriculture and are being allowed to remain on the grounds where the famed novelist once lived. The island property is now the Hemingway Home and Museum, and one of Key West’s more popular attractions. The federal agency originally wanted the cats removed or caged because the museum lacked the proper license to exhibit animals.
All the cats roaming the grounds are descended from a cat named Snowball given to the author by a ship’s captain in the 1930s. Snowball was a polydactyl cat, meaning its paws contained more than the usual number of toes. Typically a cat has 18 toes – five on the front and four on back. Polydactyls commonly have six or seven toes on the front, and sometimes an extra one on the rear, but the record is held by a California cat that had an incredible eight toes on each foot! Polydactyly is a congenital abnormality genetically passed down to offspring. In some cases the extra toes are like opposable thumbs giving the cats an almost human-like dexterity. Snowball’s descendents all carry the genetic trait but not all are polydactyl.
Ernie the cat
Courtesy Mark RyanOur family cat was a polydactyl, and we named him Ernie in honor of Hemingway and his six-toed cats. Ernie’s extra-large feet allowed him to gain lots of weight during his life with us. At his heftiest he weighed 24 pounds. He was huge, a real lard butt. His full name - Ernesto ”El Gato Gordo” Hemingway - was well deserved.
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