Happy Birthday to Charles Darwin’s Seminal Work

On this day 1859, “On the Origin of Species” by British naturalist Charles Darwin was first published, selling out by the end of the day. It introduced the scientific theory that populations evolve over generations through a process of natural selection. It presented a body of evidence — gathered from Darwin’s nearly five-year journey around the world on the HMS Beagle — that the diversity of life arose by common descent through a branching pattern of evolution.

While various evolutionary ideas had been proposed since ancient times, there was renewed interest into the 19th century as scientific knowledge increased. (In fact, fellow British naturalist Alfred Russell Wallace had independently conceived the theory of evolution through natural selection, publishing his paper on the subject jointly with Darwin in 1858.)

However, Darwin’s book was brilliant in that it was written for lay readers who were not specialists in the subject. Moreover, because he was already a famed scientist, his findings were taken seriously, with the evidence he presented generating intense scientific, philosophical, and religious discussion. Within two decades, there was widespread scientific belief in evolution with a branching pattern of common descent, although people were slow to give much credit to Darwin’s specific finding of natural selection as the primary mechanism.

Indeed, from the 1880s to the 1930s there occurred an “eclipse of Darwinism” , wherein various other mechanisms of evolution were given more credit and Darwin’s fell to the wayside. Only in the 1940s, with the development of the modern evolutionary synthesis — a set of theoretical concepts that tried to harmonize and integrate different factors in evolution — did Darwin’s concept of evolutionary adaptation through natural selection become central to modern evolutionary theory, now becoming the unifying concept of the life sciences (botany, zoology, biology, etc.)

A word about the term theory as used in science: Contrary to popular belief, a theory in science is not the same as how theory is used in everyday language. 

A scientific theory is an explanation of some aspect of the natural world that can be repeatedly tested and verified in accordance with the scientific method (rigorous observation, measurement, evaluation of results, etc.) Theories are tested under controlled conditions and/or through abductive reasoning (logical inference from a set of observations). Scientific theories are established following repeated tests and scrutiny. 

By contrast, outside the scientific context, a theory usually defines explanation that is unsubstantiated or speculative–hence why so many people wrongfully believe that evolutionary is “just a theory” in the vernacular sense, rather than the more rigorously proven scientific kind of theory.

How Altruism and Cooperation Help Us Survive

Evolution by natural selection is blamed for promoting ruthless competition as a way to succeed in life — hence concepts such as “survival of the fittest” and “Social Darwinism”, which are seen as rooted in evolutionary theory but, are in fact perversions and misunderstandings of it. Take it from the man who formulated the theory of evolution:

The conclusion that cooperative groups will flourish at the expense of more selfish ones, and that as a result moral instincts will gradually evolve, was at the heart of [Charles Darwin’s] evolutionary writings. In The Descent of Man (1871) Darwin wrote about loving and cooperative behaviours in dogs, elephants, baboons, pelicans, and other species. He thought that sympathetic and cooperative tribes and groups would flourish in comparison with communities made up of more selfish individuals, and that natural selection would thus favour cooperation.

Another tendency that Darwin shares with more recent scientists is his willingness to leap from the world of natural selection to the language of morality. Writing of the evolution of human cooperation, Darwin predicted that “looking to future generations, there is no cause to fear that the social instincts will grow weaker, and we may expect that virtuous habits will grow stronger, becoming perhaps fixed by inheritance. In this case the struggle between our higher and lower impulses will be less severe, and virtue will be triumphant.”

The idea that evolution makes selfishness and immorality pivotal to survival is not only factually wrong, but a key reason why so many people — particularly the religious — are so reluctant to accept it as true. But mounting scientific evidence has verified Darwin’s early observations that prosocial behaviors are vital to our species’ flourishing: Continue reading

New Human Ancestor Discovered

From the New York Times.

The new hominin species was announced on Thursday by an international team of more than 60 scientists led by Lee R. Berger, an American paleoanthropologist who is a professor of human evolution studies at the University of the Witwatersrand in Johannesburg. The species name, H. naledi, refers to the cave where the bones lay undisturbed for so long; “naledi” means “star” in the local Sesotho language.

In two papers published this week in the open-access journal eLife, the researchers said that the more than 1,550 fossil elements documenting the discovery constituted the largest sample for any hominin species in a single African site, and one of the largest anywhere in the world. Further, the scientists said, that sample is probably a small fraction of the fossils yet to be recovered from the chamber. So far the team has recovered parts of at least 15 individuals.

“With almost every bone in the body represented multiple times, Homo naledi is already practically the best-known fossil member of our lineage”, Dr. Berger said.

Besides introducing a new member of the prehuman family, the discovery suggests that some early hominins intentionally deposited bodies of their dead in a remote and largely inaccessible cave chamber, a behavior previously considered limited to modern humans. Some of the scientists referred to the practice as a ritualized treatment of their dead, but by “ritual” they said they meant a deliberate and repeated practice, not necessarily a kind of religious rite.

“It’s very, very fascinating”, said Ian Tattersall, an authority on human evolution at the American Museum of Natural History in New York, who was not involved in the research. “No question there’s at least one new species here”, he added, “but there may be debate over the Homo designation, though the species is quite different from anything else we have seen”.

Learn more about this seminal finding from National Geographicwith which Berger is associated (apparently, he is quite a prominent and accomplished figure in his field).

Happy Belated Darwin Day!

I had almost forgotten that yesterday was the 206th birthday of the great naturalist Charles Darwin, whose contributions to evolutionary theory represent a watershed in humanity’s understanding of itself and nature as a whole. International Darwin Day is recognized worldwide to honor his achievements as well as to celebrate the science and reason he helped further.

I do not have much time to get into the seminal importance of Darwin’s work — which I could only do so much justice to in a single blog post — but here is a cute image to commemorate the anniversary of his birth (courtesy of IFL Science and Ainsley Seago).

IFLS reminds us that all of Darwin’s work, including the decisive On the Origin of Species, can be read completely free of charge here. Enjoy!

Link

Evolution Doesn’t Favor Selfishness

When most people think of evolution, they imagine a coldly efficient process whereby only the strongest and most ruthless survive, e.g. “survival of the fittest” and social Darwinism. People often use this mischaracterization to paint naturalists — namely atheists — as immoral, or to justify a cynical and misanthropic attitude towards human nature.

But setting aside the folly of deriving so many vast implications from a natural mechanistic process, new research suggests that evolution isn’t as selfish as widely assumed. It’s a somewhat long but interesting read.

A team from Michigan State University, US, used a model of the prisoner’s dilemma game, where two suspects who are interrogated in separate prison cells must decide whether or not to inform on each other.

In the model, each person is offered a deal for freedom if they inform on the other, putting their opponent in jail for six months. However, this scenario will only be played out if the opponent chooses not to inform.

If both “prisoners” choose to inform (defection) they will both get three months in prison, but if they both stay silent (cooperation) they will both only get a jail term of one month.

The eminent mathematician John Nash showed that the optimum strategy was not to cooperate in the prisoner’s dilemma game.

Co-operating is key for evolution

“For many years, people have asked that if he [Nash] is right, then why do we see cooperation in the animal kingdom, in the microbial world and in humans,” said lead author Christoph Adami of Michigan State University.

The answer, he explained, was that communication was not previously taken into account.

In 1974, Richard Dawkins published a gene-centred view of Charles Darwin’s theory of natural selection.

He argued that it was not groups or organisms that adapt and evolve, but individual genes and each living organism’s body was a survival machine for its genes.

Prof Andrew Coleman from Leicester University explains that this new work suggests that co-operation helps a group evolve, but does not argue against the selfish gene theory of evolution.

Rather, he adds, it helps selfish genes survive as they reap the awards of inhabiting co-operative groups.

“The two prisoners that are interrogated are not allowed to talk to each other. If they did they would make a pact and be free within a month. But if they were not talking to each other, the temptation would be to rat the other out.

“Being mean can give you an advantage on a short timescale but certainly not in the long run – you would go extinct.”

These latest findings contradict a 2012 studywhere it was found that selfish people could get ahead of more co-operative partners, which would create a world full of selfish beings.

This was dubbed a “mean and selfish” strategy and depended on a participant knowing their opponent’s previous decision and adapting their strategy accordingly.

Crucially, in an evolutionary environment, knowing your opponent’s decision would not be advantageous for long because your opponent would evolve the same recognition mechanism to also know you, Dr Adami explained.

This is exactly what his team found, that any advantage from defecting was short-lived. They used a powerful computer model to run hundreds of thousands of games, simulating a simple exchange of actions that took previous communication into account.

A previous study found that selfish strategies were favourable

“What we modelled in the computer were very general things, namely decisions between two different behaviours. We call them co-operation and defection. But in the animal world there are all kinds of behaviours that are binary, for example to flee or to fight,” Dr Adami told BBC News.

“It’s almost like what we had in the cold war, an arms race — but these arms races occur all the time in evolutionary biology.”

Social insects

Prof Andrew Coleman of Leicester University, UK, said this new work “put a brake on over-zealous interpretations” of the previous strategy, which proposed that manipulative, selfish strategies would evolve.

“Darwin himself was puzzled about the co-operation you observe in nature. He was particularly struck by social insects,” he explained.

“You might think that natural selection should favour individuals that are exploitative and selfish, but in fact we now know after decades of research that this is an oversimplified view of things, particularly if you take into account the selfish gene feature of evolution.

“It’s not individuals that have to survive, its genes, and genes just use individual organisms – animals or humans – as vehicles to propagate themselves.”

“Selfish genes” therefore benefit from having co-operative organisms.

Human nature needn’t be so ruthless or competitive. As a social species, it not only makes ethical sense to work together, but it’s simply more practical.

Human Evolution: Real-Life Hobbits

Why Evolution Is True

I’m spending most of the day writing now, and it’s difficult to find time to read scientific papers and report on them.  So do excuse me for a while if I summarize new findings from (reliable) journalistic results, even though I’ll scan and link to the original paper when possible.

There are two evolution-related findings of note this week.  I’ll highlight one today and one tomorrow.

First, Homo floresiensis, the three-foot “hobbit” human whose remains were discovered on the Indonesian island of Flores in 2003, has now been designated as a real species truly distinct from H. sapiens.  This species lived fairly recently—38,000-12,000 years ago, when modern humans were already colonizing the New World—but is very distinct from H. sapiens.  Because of its size and the resemblance of the skull to those seen in certain human diseases (hypothyroidism, microcephaly, etc.), some scientists speculated that this was not…

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Why we can’t clone a Neanderthal—or any ancient organism

Sorry to burst anyone’s bubble, but you never know what future technology may hold.

Why Evolution Is True

I’m not a huge fan of sci-fi, but one sci-fi movie I have seen is “Jurassic Park.” You’ll remember that the dinosaurs in that park were cloned from dinosaur blood (which contains DNA because reptiles, unlike mammals, have red blood cells with nuclei), and that blood was from the stomachs of mosquitoes that had bitten dinosaurs and then gotten preserved in amber.  Well, that reconstruction feat is impossible for scientists at our present stage of knowledge and technical abiliity—for the very same reasons it’s impossible to re-create any ancient organism from “fossil DNA.” This is relevant because of recent speculations, fueled by Harvard geneticist George Church and picked up and disseminated widely by the press, that we might be able to clone a human Neanderthal, since we now have a sequence of the Neanderthal genome.  (I’ve written before about George Church’s accommodationism; see here and here.)

First a…

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Did Cooking Make Us Human?

According to Harvard anthropologist Richard Wrangham, in his book Catching Fire: How Cooking Made us Human, we owe our existence as Homo Sapiens Sapiens to the now-taken-for-granted habit of cooking our food. Fire allowed us to consume meat and access the high-energy proteins that contributed to the development of larger brains (since such brains require a lot of energy). It also made tough and fibrous vegetable matter more palatable, expanding our diet like never before. The unprecedented absorption of all these previously unattainable vitamins, minerals, and amino acids, over many generations, is what eventually made us the most cognitively advance life form we know.

Furthermore, according to Wrangham, not only did cooked food change our physiology, from teeth type and brain size, but it presumably influenced such things as our sexual relationships, division of labor, sociality, and numerous other behaviors. It may be a bit of strange, but it’s a fascinating point to consider.

If you’re curious, you can listen to an interesting interview with the author on Point of Inquiry, where he neatly summarizes his points. I must admit that it’s a pretty convincing hypothesis, though it’s certainly incomplete and simplistic: there are plenty of alternative and complementary factors that influenced human development beyond the consumption of digestible proteins. However, I don’t think Wrangham is claiming that cooking was the sole factor in our evolution, but rather an important catalyst. It’s very likely that all the other theories have some grain of truth to them.

Until recently, however, there was an important bit of evidence that casted doubt on Wrangham’s claims: the enlargement of human brains always appeared to have begun long before hominins started cooking, with Homo erectus, about 1.5 million years ago; in contrast, the first evidence for controlled use of fire was about 400,000 years ago. While there had been earlier reports of burned bones and vegetation associated with human presence from 1.5 million years ago, those might have been due to wildfires rather than fires controlled by humans.

Granted, Wrangham rightly noted that human molar teeth underwent a relative reduction in size around the time of Homo erectus, which would be expected if we were consuming more cooked and tenderized food. But there was still no smoking gun, as it were.
At least until very recently: a new paper in PNAS reveals evidence of controlled fire use dating back to about 1 million years ago. This was uncovered in “Wonderwerk Cave,” in northern South Africa, which yielded multiple samples of charred bone and burnt plant material. The bones, which appear to be non-human, have the same alterations we’d see in modern-day cooked bones.
The burnt plant material consisted of grasses, leaves, and brushes, since humans hadn’t yet perfected the use of cooking over logs (indeed, the highest temperature suggested by bone and plant scans is about 700 degrees C—not hot enough to be produced by wood). The bones appear to have been heated to a temperature between 400 and 500 degrees C, which, while not hot enough to cook a steak completely, can still make it edible.

The authors of the study reached this conclusion:

Thus, our data, although they do not show evidence of constructed combustion features, as listed by Roebroek and Villa as a criterion of controlled burning (3), demonstrate a very close association between hominin occupation and the presence of fire deep inside Wonderwerk Cave during the Early Acheulean. This association strongly suggests that hominins at this site had knowledge of fire 1.0 Ma. This is the most compelling evidence to date offering some support for the cooking hypothesis of Wrangham (1).

Note how cautious the report is – they’re not suggesting this is clear-cut evidence, but rather that it appears very likely that controlled fire was developed at this time and place. That’s a good sign of scientific integrity. Either way, it’s exciting to see just how much more advanced our species (and its ancestors) probably was.

Another Free Evolution DVD

A few weeks ago, I posted about free science DVDs being offered by the prestigious Howard Hughes Medical Institute (HHMI). Now the organization is providing an excellent lecture on evolution titled “Bones, Stones, and Genes: The Origin of Modern Humans,” which can be ordered at no cost here (once you register with them and fill out a form, which is quick and easy).

I haven’t received this one yet, but if it’s anything like the other one I ordered, “Evolution: Fossils, Genes, and Mousetraps,” it should be digestible and informative. It includes four presentations by three noted scientists in the field, so I’m confident of its quality. Please share your feedback if you get around to seeing this or any other DVD that’s offered.

Creationism in Schools

Even though the US Supreme Court ruled against the teaching of creationism in public schools in 1987 (as per church-state separation), efforts to re-introduce this religious belief have continued unabated to this day.

The most recent attempt was to re-package it as intelligent design, a pseudoscientific claim that certain biological developments bear the signs of an intelligent designer rather than a natural process (said designer is sometimes left vague, other times specified as the Christian God).

Because it lacked any sort of scientific merit – even by the admission of some of its proponents – this unfounded “theory” was rejected in a federal court case in 2003, along the same grounds as creationism (note that the presiding judge, John Jones III, was a regular churchgoer)

But neither the courts nor the weight of scientific evidence have done much to bury this movement. The National Center for Science Education(NCSE) has provided some recent updates, some good and others disquieting.

First, comes a patent nonstarter: a bill passed by the Indiana Senate last year that would have made it legal to teach creationism in science classes, until it was shelved by the Indiana House for its clear violation of court law. The bill can be read here, with its most damning provision being the following:

Sec. 18. The governing body of a school corporation may require the teaching of various theories concerning the origin of life, including creation science, within the school corporation.

A clear-cut case if there ever was one. Also note the term creation science, as if the story of Genesis, or some derivative thereof, was empirically and methodically established.

Moving on, there was the House Education Committee of the State of New Hampshire that had dismissed two absurd bills regarding the teaching of science in schools. As you’ll see, they were clearly doomed to fail from the start, but the fact that they were even proposed is still a bit troubling. As a local periodical reported:

The first bill, sponsored by Rep. Gary Hopper of Weare, told teachers to present all scientific theories as works-in-progress that students should challenge. The second, introduced by Rep. Jerry Bergevin of Manchester, required teachers to present evolutionary scientists’ political and religious affiliations along with their scientific theories.

Not only would the first bill attack evolution, but pretty much all the core scientific theories, such as gravity and relativity, which underpin the very workings of the universe. Imagine being taught that we pretty much shouldn’t come to a conclusion about anything we’ve learned through science. Yes, a scientific mindset requires a certain level of fallibilism – science itself is constantly progressing and reevaluating. But this bill would’ve pushed it to a ridiculous level. Meanwhile, the second bill would not only have highlighted personal details that are irrelevant to the subject matter in question, but imply that certain ideologies are to be distrusted – don’t believe the scientists who are liberal or secular, for example, regardless of the veracity of their theories.

Meanwhile, however, things aren’t looking good for science in Alabama, one of the country’s most religious states, and the only one that requires an evolution disclaimer to be stuck to every biology textbook used by public schools. The State House of Representatives has introduced a bill that allows public school students to receive academic credit for out-of-school religious instruction, provided that it’s not on school property, isn’t subsidized by the state in any way (including transportation) and is not required or sponsored by the public school that the student is attending.

The problem? Well for one thing, the idea that students can receive class credit for religious courses is clearly a way to circumvent the ban on religious instruction in public schools (note that this isn’t a study of religion, which is rightly acceptable, but actual theological teaching).

Secondly, the bill is almost certainly designed to allow for the teaching of creationism as an alternative to evolution, to the extent that even the bill’s original sponsor went on record to say that its point is “to balance the presentation of evolution in the public schools.” That clearly flies in the face of established legal precedent. How would schools regulate such courses? What if other religions or opposing denominations get involved? Suddenly, government may get tangled up in religious matters that it is forbidden from being involved in.

One silver lining to all this is that scientists in Alabama are trying to fight back. Faculty from several departments in the University of Alabama have created create an Evolution Working Group which promotes and provides the teaching of evolution (you can learn about its seminar series here. They’ve even managed to establish a Minor in Evolutionary Studies, which include relevant courses in philosophy, geology, and anthropology.

Still, it’s going to be a long and hard slog for science, especially on the evolution front, since the overwhelming majority of Americans reject the theory and see it as fundamentally opposed to their religious beliefs.