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Naturally Curious Children

Posted on January 1, 2011  Comments (4)

I write this blog because when I was a kid I was curious and had parents who gave me enough interesting answers and interesting resources to build on that curiosity. And I am still curious today. I love learning. And I love to hear about kids learning.

The Big Girl has worked out evolution

She was ecstatic when we ended up with a rooster in our ‘sexed’ chickens even though Mummy and Daddy weren’t too impressed, because she wants more little fluffy chicks. I think that counts as evidence she knows you need boys and girls to get babies.
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“What would happen if there were no boys?” This is the question she came out with the other day.

“Well, there would be no babies.” I didn’t quite get the problem seeing we were feeding the rather prolific guinea pigs at the time and we’ve been talking about separating them.
“But what if there were no boys at all? So no-one could have babies?”
“Eventually, they would all die.”
“But there wouldn’t be any left!”
“No, they would die out.”
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“How did humans start?”… a puzzled little crease in her forehead. “Because if there weren’t any around with the dinosaurs they must have started sometime. How could there be no humans and then they’re there? What was the Mummy?”
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“Well, they weren’t sudden. You know how you are a little bit different to Mummy and Daddy? That’s how it happened. The babies were just a little bit different to their parents and over a really, really long time they became people.”
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“But if there was only one it would die out.”
Well that came out of nowhere, did I miss half of this conversation?
“You know, the first person. It needs to have both a boy and a girl to have more people babies. So if there was only one it would die out.”
“Oh, from yesterday. Yes, you’re right. But people live in groups, so they’re all changing a tiny little bit at the same time.”

It is great to see developing minds at work. Exploring their natural curiosity. And taking in new information puzzling it out over time and then coming back to the ideas. This kind of curiosity is what drives learning and success.

Related: Playing Dice and Children’s Numeracy – Sarah, aged 3, Learns About Soap – Letting Children Learn, Hole in the Wall Computers – Illusion of Explanatory Depth

Boa Constrictor Gives Birth to Clones

Posted on November 3, 2010  Comments (0)

Snake gives ‘virgin birth’ to extraordinary babies

A female boa constrictor snake has given birth to two litters of extraordinary offspring. Evidence suggests the mother snake has had multiple virgin births, producing 22 baby snakes that have no father. More than that, the genetic make-up of the baby snakes is unlike any previously recorded among vertebrates, the group which includes almost all animals with a backbone.
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“All offspring are female. The offspring share only half the mother’s genetic make-up,” he told the BBC.
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Humans for example have X or Y sex chromosomes; females have two X chromosomes and males have a combination of an X and a Y chromosome. In place of X and Y, snakes and many other reptiles have Z and W chromosomes.

In all snakes, ZZ produces males and ZW produces females. Bizarrely, all the snakes in these litters were WW. This was further proof that the snakes inherited all their genetic material from their mother, as only females carry the W chromosome.

“Essentially they are half clones of their mother,” says Dr Booth. That is because the baby snakes have inherited two copies of one half of their mother’s chromosomes, including one W chromosome.
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More astonishing though, is that no vertebrate animal in which the females carry the odd sex chromosome (in this case the W chromosome) has ever been recorded naturally producing viable WW offspring via a virgin birth.

“For decades WW has been considered non-viable” says Dr Booth. In such species, all known examples of babies that are the product of parthenogenesis are male, carrying a ZZ chromosomal arrangement.

Related: No sex for all-girl fish species – Virgin Birth for Another Shark Species – Bdelloid Rotifers Abandoned Sex 100 Million Years Ago – World’s Smallest Snake Found in Barbados – Androgenesis

Researchers Explain How Rotifers Thrive Despite Forgoing Sex

Posted on February 21, 2010  Comments (1)

Bdelloid rotifers haven’t had sex for at least thirty million years. Most asexual animals are doomed to extinction. The excellent show, Science Friday, looks at the extraordinary adaptations that allow rotifers to thrive sex-free.

For millions of years, the rotifers have reproduced asexually, flying in the face of an idea known as the Red Queen Hypothesis, which states that without the advantage of sexual reproduction, more-rapidly evolving parasites and predators will eventually doom the asexual species. Now, the researchers studying the tiny organism say that its ability to dry up and blow away to greener pastures may have given the rotifers a hidden tactical edge in this evolutionary war.

The webcast provides a nice overview of the research. Every week Science Friday provides many such interesting reviews of recent scientific research.

What Are Rotifers?

Rotifers are small, mostly freshwater animals, and are amongst the smallest members of the Metazoa — that group of multicellular animals which includes humans, and whose bodies are organized into systems of organs.
Most rotifers are about 0.5mm in length or less, and their bodies have a total of around a thousand cells. This means that their organ systems are a greatly simplified distillation of the organ systems found in the bodies of the higher animals.

A typical rotifer might have a brain of perhaps fifteen cells with associated nerves and ganglia, a stomach of much the same number, an excretory system of only a dozen or so cells, and a similarly fundamental reproductive system. They have no circulatory system. It is an anomaly that despite their complexity, many rotifers are much smaller than common single-celled organisms whose world they share.
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they are able to survive long periods — even perhaps hundreds of years — in a dried or frozen state, and will resume normal behaviour when rehydrated or thawed.
Secondly, they exhibit what biologists call cell constancy — they grow in size not by cell division, but by increase in the size of the cells which they already have.

Related: Bdelloid Rotifers Abandoned Sex 100 Million Years Ago – Fungus-gardening Ant Species Has Given Up Sex Completely – Amazon Molly Fish are All Female – 50 Species of Diatoms

Bewick’s Swan Divorce

Posted on January 29, 2010  Comments (2)

photo of Sarindi and Sarind (by Colin Butters)

Experts stunned by swan ‘divorce’ at Slimbridge wetland

It is only the second time in more than 40 years that a “separation” has been recorded at the centre. Staff have described the new couplings as “bizarre”. It is not unheard of for the birds, which usually mate for life, to find a new mate but it tends to be because one of the pair has died, they said.

During the past four decades 4,000 pairs of Bewick’s swans have been studied at Slimbridge, with only one previous couple moving on to find new partners.
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First suspicions of the rare event were raised when male swan Sarindi turned up in the annual migration from Arctic Russia without his partner of two years Saruni and with a new female – newly-named Sarind – in tow.

The pair’s arrival led conservationists to fear the worst for Saruni. But shortly afterwards Saruni arrived at the wetlands site – also with a new mate, Surune.
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As for why they may have split, she said: “Failure to breed could be a possible reason, as they had been together for a couple of years but had never brought back a cygnet, but it is difficult to say for sure.”

Bewick’s swans are the smallest and rarest of the three species found in the UK and each individual can be identified by their unique bill pattern.

Related: Bewick’s swan diary – Darwin’s Beetles Surprising Sex Lives of Animals – Backyard Wildlife: Crows – Duckling imprinted on this puppy in China – Bird Species Plummeted After West Nile

Fungus-gardening Ant Species Has Given Up Sex Completely

Posted on January 9, 2010  Comments (7)

The complete asexuality of a widespread fungus-gardening ant, the only ant species in the world known to have dispensed with males entirely, has been confirmed by a team of Texas and Brazilian researchers.

photo of christian rabeling excavating ants in BrazilGraduate student Christian Rabeling excavating fungus-farming ant nests in Brasilia.

Most social insects—the wasps, ants and bees—are relatively used to daily life without males. Their colonies are well run by swarms of sterile sisters lorded over by an egg-laying queen. But, eventually, all social insect species have the ability to produce a crop of males who go forth in the world to fertilize new queens and propagate.

Queens of the ant Mycocepurus smithii reproduce without fertilization and males appear to be completely absent, report Christian Rabeling, Ulrich Mueller and their Brazilian colleagues in open access journal PLoS ONE this week.

“Animals that are completely asexual are relatively rare, which makes this is a very interesting ant,” says Rabeling, an ecology, evolution and behavior graduate student at The University of Texas at Austin. “Asexual species don’t mix their genes through recombination, so you expect harmful mutations to accumulate over time and for the species to go extinct more quickly than others. They don’t generally persist for very long over evolutionary time.”

Previous studies of the ants from Puerto Rico and Panama have pointed toward the ants being completely asexual. One study in particular, by Mueller and former graduate student Anna Himler (now at Arizona State University), showed that the ants reproduced in the lab without males, and that no amount of stress induced the production of males.

Scientists believed that specimens of male ants previously collected in Brazil in the 1960s could be males of M. smithii. If males of the species existed, it would suggest that—at least from time to time—the ants reproduce sexually.

Rabeling analyzed the males in question and discovered that they belonged to another closely related (sexually reproducing) species of fungus-farmer, Mycocepurus obsoletus, thus establishing that no males are known to exist for M. smithii. He also dissected reproducing M. smithii queens from Brazil and found that their sperm storage organs were empty.

Taken together with the previous studies of the ants, Rabeling and his colleagues have concluded that the species is very likely to be totally asexual across its entire range, from Northern Mexico through Central America to Brazil, including some Caribbean islands.

As for the age of the species, the scientists estimate the ants could have first evolved within the last one to two million years, a very young species given that the fungus-farming ants evolved 50 million years ago.

Rabeling says he is using genetic markers to study the evolution and systematics of the fungus-gardening ants and this will help determine the date of the appearance and genetic mechanism of asexual reproduction more precisely in the near future.

Full press release

Related: Bdelloid Rotifers Abandoned Sex 100 Million Years Ago – Amazonian Ant Species is All Female, Reproduces By Cloning – Female Sharks Can Reproduce Asexuality – Amazon Molly Fish are All Female

Friday Fun: Bird Mimics Other Birds and More

Posted on November 27, 2009  Comments (3)

The lyre bird, not only mimics the calls of other birds, buy also man made noises such as cameras, saws and chainsaws, in an attempt to impress potential mates. David Attenborough narrates the above clip.

Related: Friday Fun: Bird Using Bait to Fish – Leafhopper Feeding a Gecko – Backyard Wildlife: Raptor – Bdelloid Rotifers Abandoned Sex 100 Million Years Ago

Amazonian Ant Species is All Female, Reproduces By Cloning

Posted on April 19, 2009  Comments (0)

Ants inhabit ‘world without sex’

The ants reproduce via cloning – the queen ants copy themselves to produce genetically identical daughters. This species – the first ever to be shown to reproduce entirely without sex – cultivates a garden of fungus, which also reproduces asexually.
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Dr Himler’s interest in Mycocepurus smithii was originally sparked not by their unusually biased sex ratio, but by their ability to cultivate crops. “Ants discovered farming long before we did – they have been cultivating fungus gardens for an estimated 80 million years.

“They collect plant material, insect faeces and even dead insects from the forest floor and feed it to their crops,” she said.

Related: Royal Ant Genes – Bdelloid Rotifers Abandoned Sex 100 Million Years Ago – Blind “Ant From Mars” Found in Amazon – Amazon Molly Fish are All Female

Darwin’s Beetles Still Producing Surprises

Posted on February 7, 2009  Comments (2)

As part of National Science Foundation-funded research on the evolution of male dimorphism in insects, biology professors J. Mark Rowland, UNM, and Douglas J. Emlen, UM, were surprised to find that many species of beetles are capable of producing not only two, but three different types of males.

The sex lives of animals is known to be complicated business. Where competition in mating is particularly intense, many kinds of animals produce enlarged weapons that function in male combat and utilize alternative tactics in deploying them. Such exaggerated structures include horns in dinosaurs and deer, and tusks in elephants and walrus.

Elaborate male weapons are also known to occur in many types of insects. Now it appears, as the research of Rowland and Emlen illustrates, that male weaponry and alternative mating tactics can be much more complex in the lives of beetles than previously imagined.

“We discovered a novel mating system in which the individual males of various species of beetles have the capacity to express one of three alternative morphologies,” said Rowland. “In many dung beetles , smaller males are unlikely to prevail in direct contests with alpha males. These beta males develop disproportionally smaller horns and employ alternative, less aggressive, reproductive tactics.

“The trimorphic species reported here have alpha, beta and gamma (completely hornless) male – three qualitatively distinct forms. A mating strategy with three such tactics implies considerable complexity, but may actually involve operational rules reminiscent of the old rock, paper, scissors game.”
Continue reading →

Amazon Molly Fish are All Female

Posted on April 24, 2008  Comments (2)

No sex for all-girl fish species

A fish species, which is all female, has survived for 70,000 years without reproducing sexually, experts believe.
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The species, found in Texas and Mexico, interacts with males of other species to trigger its reproduction process. The offspring are clones of their mother and do not inherit any of the male’s DNA. Typically, when creatures reproduce asexually, harmful changes creep into their genes over many generations.
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One theory is that the fish may occasionally be taking some of the DNA from the males that trigger reproduction, in order to refresh their gene pool.

Dr Laurence Loewe, of the university’s School of Biological Sciences, said: “What we have shown now is that this fish really has something special going on and that some special tricks exist to help this fish survive. “Maybe there is still occasional sex with strangers that keeps the species alive. Future research may give us some answers.”

He added that their findings could also help them understand more about how other creatures operate. “I think one of the interesting things is that we are learning more about how other species might use these tricks as well,” he said. “It might have a more general importance.”

Related: Female Sharks Can Reproduce Alone – Only Dad’s Genes – Bdelloid Rotifers Abandoned Sex 100 Million Years Ago – Sex and the Seahorse – more posts about fish

Really Old Coral – Over 2,000 Years Old

Posted on February 18, 2008  Comments (3)

photo of sea coral (leiopathes_glaberrima)

Worlds oldest animal aged to 4000 years

deep-sea gold corals (Geradia sp.) and black corals (Leiopathes glaberrima, pictured left) indicate these animals live between two and four millennia
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The new findings break all records previously claimed for marine invertebrates like the cold seep tubeworms (estimated 200 years old), quahog clams (estimated 400 years old), as well as the deep-sea wannabees Primnoa spp. and bamboo corals (45 – 300 years old). Given the new results, deep-sea animals can finally measure up to the longevity of the “Methuselah tree”, the Bristlecone Pine, estimated to be near 5000 years old.
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perhaps the most important thing to mention is that gold and black corals are colonial zoantharians. No single polyp is thought to be this old, just the skeletal axis.

How is Coral an animal?

Coral is an animal that belongs to the phylum cnidaria…
During the mating season coral polyp release eggs and sperm into the water (picture below) and when an egg and a sperm meet they form a larva known as a planula…
The baby coral looks like a little tiny jellyfish and it floats around in the water until it finds a hard place to attach to, usually a coral reef. Then it lands and starts to build itself a shell. It builds it by combining carbon dioxide (CO2) and calcium (Ca) in the water to make calcium carbonate (CaCO3) also known as limestone. This shell is shaped like a round vase and the coral polyp lives inside…

Related: South Pacific to Stop Bottom-trawling – Batfish Key to Keeping Reefs Clean – Bdelloid Rotifers Abandoned Sex 100 Million Years Ago

The Science of Kissing

Posted on February 11, 2008  Comments (1)

The Differences in Gender — Sealed With a Kiss

In people, kissing to express affection is almost universal. About 90 percent of human cultures do it. One traditional view is that kissing, known scientifically as osculation, evolved from women chewing food for their children and giving it to them mouth-to-mouth, Fisher said.

But, she said, “I’ve never believed that,” adding that similar behavior is found in many species. Birds tap beaks. Elephants shove their trunks in each other’s mouths. Primates called bonobos practice their own version of French kissing. Fisher believes kissing is all about choosing the right mate.

“There’s so much information exchanged when you kiss someone that I just thought it must play a vital role in mate choice, and this paper is elegantly showing that,” Fisher said. A disproportionate amount of the brain, she noted, is geared toward interpreting signals from the mouth.

The research paper – Sex Differences in Romantic Kissing Among College Students: An Evolutionary Perspective

Related: The Psychobiology of Romantic Kissing – Sexy Math – Summer Camp Psychology Experiment

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