Archive for the ‘life sciences’ Category

Happy birthday, Charles Robert Darwin

Charles Darwin, shortly after his return from the voyage of the Beagle. If he were still alive, he'd be 200 years old today

Charles Darwin, about age 30, shortly after his return from the voyage of the Beagle. If he were still alive, he'd be 200 years old today.

Today is the 200th birthday of Charles Darwin (and of Abraham Lincoln too; they were born within hours of each other).  Darwin, who I have previously blogged about here, ranks with Newton and Einstein as one of the most important scientists of all time.  So take a bit of time today to learn more about this extraordinary individual.

To humanize him and add some context and framework for his accomplishments, here is a brief time line of some notable events in Darwin’s life, which may contain some facts that you don’t yet know about the great naturalist:

12 February 1809: Charles Robert Darwin was born in Shrewsbury, Shropshire, England, the fifth of six children to physician Robert Darwin and Susannah (née Wedgwood) Darwin, the daughter of industrialist Josiah Wedgwood (1730- 1795).

1825–1828: Studies medicine at the University of Edinburgh. He joins the Plinian Society, a group for students interested in natural history. He gives up medicine because he can’t stand the sight of blood and 19th century surgery.

1828–1831: At his father’s urging, he begins preparing for a career in the clergy; he studies theology at Christ’s College, University of Cambridge, in preparation for a career as a parish priest. He collects beetles and enrolls in a course run by Rev. John Stevens Henslow, professor of botany.

HMS Beagle surveying the coast of South America

HMS Beagle surveying the coast of South America

1831–1836: At the suggestion of Rev. Henslow, he accompanies Captain Robert FitzRoy (1805–1865), future admiral and Governor of New Zealand, on the second survey expedition of HMS Beagle as an unpaid naturalist. Originally planned to take two years, the five-year voyage takes him across the Atlantic to the southern part of South America, returning via Tahiti and Australia; the Falkland Islands, Argentina, Chile, Peru, Australia, New Zealand, Mauritius and South Africa featuring on his extensive itinerary. He observed the behavior of different plant and animal species, and analyzed his large collection of specimens for three months on his return.

1838: Moves to London and, once compiled, he begins publishing his findings in various papers and volumes.

1839: Journal and Remarks (later known as The Voyage of the Beagle) appears in print and he is elected a Fellow of the Royal Society on 24 January. Five days later he marries his cousin Emma Wedgwood (1808–1896), the youngest of seven children to potter Josiah Wedgwood II (1769–1843), and his wife Bessy. They would have 10 children, two sadly dying in infancy. George, Francis and Horace became, respectively, an astronomer, botanist and civil engineer of repute. Charles and Emma were avid backgammon players; he faithfully records the results of their nightly games for many years.

1842: The Darwins move to Downe House in the village of Downe, Kent.  He does his theorizing in his home study, in part so he can be close to his children.  He publishes his first book on a specific subject, The Structure and Distribution of Coral Reefs.

1853: He is awarded the Royal Society’s Gold Medal for his four volumes on barnacles.

1856: Darwin becomes aware of Alfred Russell Wallace’s theories on evolution and is persuaded to finally publish his work to establish priority.

1858: The outlines of his natural selection theories are jointly published alongside the similar theory proposed by Alfred Russell Wallace (1823-1913) in the Journal of the Proceedings of the Linnean Society. His grandfather, scientist Erasmus Darwin (1731-1802), was one of those who had already argued in favour of evolutionary ideas.

1859: His epic On the Origin of Species, a collection of evidence collected from the study of fossils, comparisons of anatomy and embryology, appears after more than 20 years in the making. It presents a theory in which living beings are related by common genealogical descent; discourses that life on earth adapts according to its environment; and offers views on such concepts as natural selection, adaptation and survival of the fittest.

1871: The Descent of Man, and Selection in Relation to Sex is published; it links, in Part I, some of the ideas detailed in On the Origin of Species to the concept of human evolution, a topic already being discussed in detail by peers, and looks at the relationship between human sexes and races, responding to the thoughts and works of other writers in the process. In Part II and Part III, the book focuses on what he calls “sexual selection.”

1872: The Expression of the Emotions in Man and Animals is published; it looks at how humans and animals communicate their emotions.

1877: He is awarded an honorary degree from the University of Cambridge.

19 April 1882: He dies in Downe and is subsequently buried near Isaac Newton in Westminster Abbey following one of only five state funerals given to a non-royal in the 19th century.

Darwin continued his research throughout his life and his work was not merely confined to the biological sciences.

The first evolutionary tree ever drawn, with the words "I think" written above it, from one of Darwin's notebooks

One of the first evolutionary trees ever drawn, with the words "I think" written above it, from one of Darwin's notebooks.*

His first specific-subject book, The Structure and Distribution of Coral Reefs, published in 1842, set out his theory—controversial for decades but later proven correct—of how atolls form, overturning the prevailing theories of his day.  His last work, published the year before he died, The Formation of Vegetable Mould, Through the Actions of Worms, With Observations on Their Habits, analyzed the role that worms play in soil creation.  His conclusions, once again, would be proven correct with time.

Darwin was a skilled writer and very effective at conveying his thoughts and ideas—and not just scientific ideas; his other works include interesting travelogues and an autobiography. Almost all of his writings, including some of the most speculative, have aged very well.

I cannot help including an example, and if it is a long one it is, I hope, a good one.  Consider the concluding paragraph to his best-known work, On the Origin of Species, which sums up with some degree of poetry the whole work:

It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with Reproduction; Inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the external conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.

If you want to learn more about Charles Darwin’s early life and family life, along with the discoveries that led to his formation of the theory of evolution, I highly recommend the following hour-long video of a 2005 lecture by Sean Carroll, titled (not coincidentally) “Endless forms most beautiful.”

Carroll is a great lecturer and the video includes many slides and videos that I think will hold your attention if you have even the smallest bit of interest in the subject.

darwinbadgeFor more on the Charles Darwin, see the excellent series of articles that Wikipedia has covering his whole life.  For more on the theory of evolution, which is one of the most important and central in all of science, see their introduction to evolution and the somewhat more technical article on the theory itself.  Berkeley has a nice page with explanations of evolution, the importance of the theory, and the many forms of evidence on which it is based.


* This post originally identified Darwin’s sketch as “the first evolutionary tree ever drawn.”  However, as commenter Zen Faulkes points out (see comments below), Jean Baptiste Lamarck had previously drawn a similar sketch. This blog regrets the error.

Woman becomes mother at age 70, sets record

The Flag of India is a horizontal tricolor with the 24-spoke Ashoka Chakra wheel in the middle

The Flag of India is a horizontal tricolor with the 24-spoke Ashoka Chakra wheel in the middle

Rajo Devi of Alewa, India has become the oldest woman ever to give birth, as reported by Slate. She is 70 years old; the father, her husband, is 72.

Obviously, she is two decades past menopause and incapable of having children normally.  However, there are fertility treatments now by which a woman can have a child at virtually any age.  But just because we can do a thing does not mean that we must do that thing.  Or even that we should.  Rajo Devi and her husban will be octogenarians by the time the kid is 10.  I’m not sure what the age of majority is in India, but the mom will be 88 when the kid is 18.  How is this a good idea?

The desire to be parents is natural and understandable.  But if you can’t have children naturally, as Rajo Devi and her husband couldn’t, why not adopt?  There are surely enough orphans in the world (a lack of them would be a problem worth having). Why create a new child who will be deprived of parents while still young?  I think that maybe we should think a little bit more about this whole old people having babies after drastic medical intervention thing.

Burlington, VT is healthiest city & Huntington, WV is unhealthiest city in America

Burlington, Vermont may have healthy residents, but they have a terrible flag

Burlington, Vermont may have healthy residents, but they have a terrible flag

The Centers for Disease Control has completed a survey of the United States and found that Burlington, Vermont (pop. 39,000) is the healthiest city in the United States.  The city is among the best in exercise and among the lowest in obesity, diabetes, and other measures of ill health; and 92% of residents report being in good or great health.

At the other end of the health spectrum is Huntington, West Virginia (pop. 49,000).  Many of their health challenges there are related to obesity.

Huntington is essentially tied with a few other metropolitan areas for proportion of people who don’t exercise (31 percent), have heart disease (22 percent) and diabetes (13 percent). The smoking rate is pretty high, too, although not the worst.

However, the Huntington area is a clear-cut leader in dental problems, with nearly half the people age 65 and older saying they have lost all their natural teeth. And no other city comes close to Huntington’s adult obesity rate, according to the report by the U.S. Centers for Disease Control and Prevention, based on data from 2006.

The dental statistic jumps out at me: 48.1% of people over 65 in Huntington have none of their original teeth left.

Some of the differences between the healthiest and unhealthiest cities are interesting:

  • Burlington is younger, with an average age of 37, compared to 40 in Huntington, according to the Census Bureau.
  • Burlington is better off financially, with 8 percent living at the federal poverty level, compared to 19 percent in Huntington.
  • It’s much more educated, with nearly 40 percent of area residents having at least a college bachelor’s degree. Only 15 percent in the Huntington area do.

This flag is an abomination.  In a 2004 flag survey conducted by the North American Vexillogical Association only one city had a worse flag than this

Huntington, WV's flag is an abomination. In a 2004 North American Vexillogical Association flag survey only one city in the country had a worse flag than this

Poverty is a significant factor in Huntington’s high obesity rate and other health problems; people there don’t have much leisure time to exercise and often can’t afford to eat healthy foods. The news story refers to “the KFC $10 Challenge” which the the fried-chicken chain is advertising.  They challenge a family to go to the grocery store and put together a dinner for $10 or less that was comparable to KFC’s seven-piece, $9.99 value meal. “This is what we’re up against,” said Keri Kennedy, manager of the West Virginia health department’s Office of Healthy Lifestyles.  She notes that it’s an extremely persuasive ad for a low-income family that is accustomed to fried foods. “I don’t know what you do to counter that.”

Cheetahs on a plane!

No, this blog entry doesn’t share a title with an upcoming Samuel L. Jackson movie; it’s about a real event!  There were cheetahs.  And they were on a plane.  And one of them was loose!  Well, okay, it was just in the cargo hold.  But still.

A cheetah in its natural, non-airplane environment

A cheetah in its natural environment. Curiously, this picture was uploaded to Wikipedia by user "Jacoplane."

Yahoo has the story.  Apparently, the pair of 1-year old female cheetahs were being transported in the cargo hold of a Delta Airlines flight from the Wildlife Safari Park in Winston, Oregon to the Memphis Zoo in Tennessee.  Somehow, one got out of her cage and was eventually discovered in Atlanta by a surprised baggage handler when she opened the cargo hold (and presumably closed it again very quickly).

Happily the situation was resolved favorably for all involved, human and feline.   Delta got help from the folks at the Atlanta Zoo, who tranquilized both animals and removed them from the aircraft.  There was, however, a delay in passengers getting their luggage, but fortunately none was damaged by the cats.  Note that cheetahs are the only cats that cannot retract their claws.

I’ve always liked cheetahs.  I think as a kid I just thought it was cool that they were the fastest land animal on the planet, able to run up to 77 mph according to one book I had (peregrin falcons and some other bird species can achieve much greater speeds when performing an aerial dive). Unfortunately, cheetahs suffer from very low genetic variability, the result of going through an extremely narrow population bottleneck during the last ice age about 10,000 years ago; genetic research indicates that as few as seven cheetahs that were alive at that time passed on their genes.  The animals are so genetically similar that skin grafts between unrelated cheetahs are rarely rejected.  Negative consequences of this paucity of genetic variation include trouble breeding, high mortality among cubs, and poor immune systems.  I wonder if their inability to retract their claws is also related?

In any event, to learn more about these fascinating and beautiful animals, see Wikipedia’s article thereon.  And, hopefully, more cheetahs won’t be getting loose on planes anytime soon.

Researchers learn about lovesickness from rodents

A group of reseachers led by Larry Young, a psychiatry professor at Emory University’s Center for Behavioral Neuroscience, in Atlanta, have some interesting findings on the causes of lovesickness.  They studied prairie voles, one of the few animals that generally practices lifelong monogamy, and discovered changes in brain chemistry when a prairie vole is separated from its mate.  (See “Brain Chemical Could Spur Lovesickness“)

Young and his group examined the brains of a variety of adult male voles. Some of the voles had lifelong female partners, while other hadn’t had time to form such bonds and were best acquainted with brother or sister voles.

All of the voles were subjected to brief stress tests, such as a swimming challenge, or being placed in a maze.

“The ones who were [still] with a partner, or had just been separated from a sibling so they never formed a romantic bond in the first place, actively avoided the aversive or stressful situation,” Young noted.

But what about male voles who had been recently separated from a longtime female partner?

These voles “basically were passive — they gave up,” Young said. “I would be hesitant to say that these animals were depressed, but their behavior is reminiscent of what you would see in a depressed person.”

These guys may be able to tell us about romantic love

These guys may be able to tell us about romantic love

The brains of the lovesick voles had heightened activity of a chemical messenger called corticotropin releasing factor (CRF) in an area of the hypothalamus, an area of the brain heavily involved in emotions.  When the researchers administered a drug that blocked CRF activity, the behavioral differences between the voles who’d been separated from their mates and those that were not disappeared.  CRF activity kicked in only when the vole was separated from a longtime female partner, not a sibling companion.

This all suggests a mechanism designed to push mating pairs back together if separated.  It also suggests, according to experts, the possibility of a pharmaceutical fix for lovesickness.

The findings were published on Oct. 15 in the journal Neuropsychopharmacology.

Monday Miscellany: oceans, stars, and Gordon Brown

Here are some of the news stories that have caught my attention in the past week. If you find any of them interesting, please comment!

After a century of study, we're still finding new creatures everywhere we look in the ocean

We barely know what lives here. And don't build your house to close to this thing if you live in Texas.

The ongoing Census of Marine Life, an international effort to catalog all life in the oceans, has announced the discovery of hundreds of previously unknown species. They were found on various coral reefs and join thousands of other new species that the Census has discovered. Literally every where they look in the oceans, no matter how well previously explored, scientists are finding new species. The survey is expected to be completed circa 2010.

Speaking of the oceans and seas, hundreds of people on the Texas coast may soon lose their homes on account of Hurricane Ike and a 1959 state law that makes all coastal land between the low tide mark and the high tide mark public property and illegal to build upon. The hurricane has eroded many beaches severely, so many homes that were previously back from the water are now within that zone. Owners whose property is condemned by the state would probably get nothing in return, and it may take up to a year in some areas for the state to determine if the homes are indeed on public property now (it’ll take a while to see how the tides will act throughout the year). The law was last widely used in 1983 after Hurricane Alicia. I don’t think we should feel too bad for these people. “Every one of them was warned of that in their earnest money contract, in the deed they received, in the title policy they bought. … And whether you like it or not, neither the Constitution of the United States nor the state of Texas nor any law permits you to have a structure on state-owned property that’s subject to the flow of the tide.” These folks knew the risks and decided to take their chances. Unfortunately, they’ve lost their gamble.

If you've bought a Harry Potter book, this guy's party may have some of your money!

If you've bought a Harry Potter book, this guy's party may have some of your money!

On the other side of the pond, Harry Potter author J. K. Rowling has donated £1milllion (about $1.8 million) to the Labour Party, saying “I believe that poor and vulnerable families will fare much better under the Labour Party than they would under a Cameron-led Conservative Party.” This is the first time she has donated to the party and some cynics speculate that she is angling for a spot on the British honours list. Dame Rowling, perhaps? The Labour Party can probably use the money; they trail the Conservative Party in polls by about 12 points, though this is down from a 21 point defecit last month. Perhaps Gordon Brown’s declaration that he “wants to do better” as Prime Minister has helped his party out some? He doesn’t need to call elections until five years after the last ones, in May 2005, but they’re typically held a year before the parliament’s term expires unless the party in power is doing very poorly.

In American election news, despite none of the presidential debates having been held yet, millions of people can already cast their ballots in this years contests. In all, 36 of the 50 states have some form of early voting, though details vary by jurisdiction. In Virginia, considered an important swing state in the contest between Barack Obama and John McCain, citizens can already vote right now. In all, up to one third of voters are expected to take advantage of early voting or absentee ballots. Hopefully few of those voters get buyers remorse between now and election day. Of course, half the electorate gets buyers remorse after the election, so they’re really just doing that ahead of us too. (Note that I’m not posting a picture of Virginia’s state flag on account of it sucks really bad.)

Dark matter probably helped form these galaxies, which probably contain some super-massive stars

Dark matter probably helped form these galaxies, which probably contain some super-massive stars

Somewhat farther away, astronomers have identified the most massive star ever found in our galaxy. The previous record holder was about 83 times the mass of the Sun; this beast is 115 times the mass of our favorite star, and it happens to be orbited by the next most massive star ever discovered, which weighs in at 89 solar masses. The astronomers’ calculations have a margin of error of +/- 30 and 15 solar masses, respectively, for the two newly studied stars. Theoretically, the maximum size a star could possibly be is 150 solar masses. The larger a star is, the more quickly it burns out.

Some other astronomers have discovered a new galaxy, Segue 1, which despite orbiting the Milky Way was not previously studied on account of being only 1/1,000,000,000th as bright as our own galaxy. However, Segue 1’s gravity is about 1000 times greater than would be predicted based on it’s luminosity alone, indicating that it is chock full of way more dark matter than would be expected. Very little is known about dark matter, and there are still a few scientists who are skeptical that it exists, but the evidence is very strong. Most cosmologists think that dark matter plays an important role in the formation of galaxies, meaning we wouldn’t be here if it wasn’t. It is thought that there is approximately six times as much dark matter as normal matter in the universe, but that it only makes up about 23% of the universe, with almost all the rest being even more mysterious dark energy, which drives the expansion of the universe. In other words, we don’t know what 96% of the universe is. We’ll not run out of things to learn any time soon!

I hope this helps get your week off to an interesting start. Have a good one.

Protecting fisheries

The Economist has an interesting story about privatising fisheries. Or, as we Americans would write, privatizing them. This is an important issue, since a 2006 study indicated that all of the world’s fisheries could collapse by 2048 if current trends continue. Preventing overfishing is extremely important, but without any regulation fishermen have an incentive to simply grab as much as they can as quickly as they can, leading to the tragedy of the commons.

The article in question describes a system currently in use in 121 of the worlds approximately 10,000 fisheries that allocates how much a company can catch through use of Individual Transferable Quotas, which, as the name implies, can be bought and sold. ITQs can be held long term, so companies have a strong incentive to maintain the fishery in which they have a large stake. Research into those areas where ITQs are used indicates that they can halt, and even reverse, the collapse of fisheries, on which much of humanity depends for food and livelihood. Promisingly, fishermen grasp the usefulness and value of this system to themselves and their own long-term prospects. Market forces and intelligent planning can lead to a situation that’s better for consumers, workers, business, and the environment without heavy-handed government regulation.

The Economist warns against government micromanaging the system, which would eliminate many of the free market benefits, leading to a less efficient system, and which would be prone to undue lobbying influences.

Church of England apologizes to Charles Darwin

The Rev. Malcolm Brown, the head of the Church of England’s public affairs department, has said that the Church owes Charles Darwin an apology, “for misunderstanding you and, by getting our first reaction wrong, encouraging others to misunderstand you still.” He said that in a larger essay, “Good religion needs good science,” which itself if part of an excellent series of articles and essays, found at here, on Darwin that the Church of England is releasing in advance of 2009, which is both the bicentennial of the scientist’s birth and the 150th anniversary of the first publication of On the Origin of Species.

Charles Darwin, shortly after his return from the voyage of the Beagle

Charles Darwin in the late 1830s, shortly after returning from the Beagle's historic voyage

They compare hostility to Darwin and evolution to the opposition that Galileo faced for saying the Earth moved around the Sun. Pope John Paul II officially apologized for the Catholic Church’s role in putting Galileo on trial and stifling his ideas. Some have criticized the apology, calling it “ludicrous” or “pointless,” the latter being the characterization of Darwin’s great-great-grandson.

I think it is appropriate to admit fault where it is real, but care should be taken to not distort the history of the church’s reaction to the theory of evolution which is certainly not the story of universal rejection. Indeed, the publication of The Origin of Species in North America was organized by Darwin’s confidante, Asa Gray, professor of natural history at Harvard and a committed Christian. (Gray later wrote a book titled Darwiniana.) The British historian James Moore writes that “with but few exceptions the leading Christian thinkers in Great Britain and America came to terms quite readily with Darwinism and evolution”, and the American sociologist George Marsden reports that “…with the exception of Harvard’s Louis Agassiz, virtually every American Protestant zoologist and botanist accepted some form of evolution by the early 1870s.” And it wasn’t just scientists among Christians who quickly embraced evolution. One Anglican clergyman wrote to Darwin suggesting that evolution was actually a “loftier” conception of God than the old-fashioned idea of God creating humans the easy way, by just molding them out of dust. In other words, there is grandeur in this view of life.

I do very highly recommend the articles published by the Church of England on Darwin and his life, though I have only begun to skim through them myself. They point out that Darwin was raised and always surrounded by Anglicans and even studied briefly for the priesthood as a young man (some Islamic Creationists take this to be proof that evolution is a Christian plot to undermine the morals of good Moslems). His journey away from Christian faith into what he later said was best characterized as agnosticism, not atheism, had nothing to do with his scientific discoveries; it was largely the result of his daughter’s death, which he found difficult to square with the existence of a loving, all-powerful God.

Darwin knew that his research and theories would prove controversial and expected the attacks that he received. However, his fears that his family and friends would reject him were happily unfounded. When he died in 1882, he became one of only five non-royals to be given a state funeral in the 19th century and was buried in Westminster Abbey, close to John Herschel and Isaac Newton.

Comments are welcome. And you can check out those aforementioned articles here:

McCain and Obama on science

Back during the primary season Science Debate 2008 originally wanted to get all the candidates from both parties on the same stage to debate their respective views, approaches, and policies towards science-related topics.  That didn’t happen.  But what is about as good as could be hoped for is that both Barack Obama and John McCain have now submitted answers to questions they were given in a range of categories that together cover the spectrum of issues that face us and that require a scientific approach.

The 14 categories are: innovation, climate change, energy, education, national security, pandemics and biosecurity, genetics research, stem cells, ocean health, water, space, science integrity, research, and health.

The candidates’ written responses can be seen and compared side-by-side here.  Highly recommended, even for those who have already made a decision about who to support.