Tag Archives: Nature

31 Days – Unconscious Life

Take a look at these moon jellies swimming around in the San Francisco Aquarium. Do you find them as fascinating as I do?

The video is not mine, but I did have a chance to see the display when I visited San Francisco earlier this year. Some of the jellies had decided to swim from here to there with well-coordinated pulses of their bells; others had decided to just hang out. What was fascinating for me to contemplate was that their decision-making was an illusion. Jellies have no brains, and thus cannot “decide” anything.

On Day 4 (OK, I’m a day late) of 31 Days of Wonder, I’d like to consider jellies and other unconscious life.

I’ve written before about how consciousness is a matter of degree. As Douglas Hofstadter delightfully points out in his book, I Am a Strange Loop, even a thermostat has some degree (sorry) of consciousness: It “observes” the temperature and “decides” to open or close a circuit when certain thresholds are crossed.

But that’s not what we mean by “conscious life,” is it? We mean something like self-awareness. We might grudgingly concede that the thermostat is “aware” of temperature, but there is no sense in which it is aware of itself.

Is a jelly aware of itself? It’s hard to imagine an animal that’s not, but let’s consider all that happens in our own bodies without our awareness. Here’s a drama that is playing out in your body right now. Although less than a minute long, it would make a worthy sequel to Star Wars, complete with a Death Star.  Pathogens attack a cell, and then antibodies arrive and foil the attack. Finally, a macrophage engulfs a pathogen. (Full explanation here.)

Although fighting off invading cells is high drama, you could not be aware of it even if you tried, because it is disconnected from your brain. What if every process in your body were like that? What if you didn’t even have a brain?

Here’s the wonder: It’s impossible to imagine what such life would be like because if you were such a life-form, you couldn’t imagine anything.

31 Days – Color

Color – one of our most basic perceptions – is a fiction.

I’m not suggesting that “it’s all a dream” but color is only the interpretation we give to different wavelengths of light. Is there a reason that a photon whose squiggles are 400 nanometers long should look violet, while the same photon slowed down to a wavelength of 570 nanometers should have the “opposite” color, yellow? If there is a connection, it is so remote as to appear arbitrary, and philosophers are still arguing about it.

However that debate plays out, we have the raw data (wavelength) and a very different interpretation (color).

Astonishingly, we are unconscious of the raw data. A child could stare all day at a cherry and a lime and have no way to tell you whether the red or the green had the shorter wavelength. In fact, if you were to ask him the question, he wouldn’t even know what you’re talking about. How amazing is that?

We invent (?) color to interpret the very different phenomenon of wavelength, and then we take the further step of assigning emotional states to colors. In some cases, the reason is clear: Black conveys doom because scary things do happen in the dark. In others, the assignment is arbitrary: Red means “danger” to an American, but “good luck” to the Chinese.

So the next time you’re bored and restless at a stoplight, maybe you’ll use the moment to marvel with me at how a wavelength of 650 nanometers came to mean “stop.”

31 Days – Ribosomes

I hope you enjoyed yesterday’s videos of Charlotte and Jonathan. And now for something completely different: an excursion to geekdom.

This year, I was home-schooling one of my daughters in biology and totally fell in love with the subject. We’ll probably go there more than once during August’s 31 Days of Wonder. One of the most fascinating biological processes is the assembly of proteins by ribosomes.

Ribosomes are ugly, gnarly molecules that float around in in your cells. As you’ll see in the video, other molecules called mRNA (messenger RNA) emerge from the nucleus bearing your genetic code, which is in the form of nucleotide triplets called codons. The ribosome latches itself onto the mRNA, recruits amino acids that match the codons, and sticks the amino acids together to form the proteins that form everything from bones to brain. The proteins come out of the ribosome looking very much like poop coming out of a guppy.

The process would be amazing enough if a thinking human were doing it, but the fact that lumpy, unconscious molecules pull it off is truly a wonder.

And that’s only the general idea. The ribosome also proofreads what it does and discards the protein if there was a mistake. Amazing.

The Selfish Gene – Part 5

<< Previous in this Series: The Selfish Gene – Part 4 (Chapter 10)

Chapter 11 – Memes: The New Replicators

The ideas in this final chapter have penetrated popular culture more thoroughly than everything in the previous ten chapters combined. That’s fitting, because it’s is all about how ideas penetrate popular culture!

This is the chapter in which Dawkins coined the word meme to mean a replicating unit of cultural evolution. Examples include “tunes, ideas, catch-phrases, clothes, fashions, ways of making pots or building arches.” Amusingly, the word itself has evolved additional meanings, but this is where it all started.

The first 10 chapters of this book explained how genes, which can neither think nor decide, have managed to construct (wait…they can’t manage either, but you know what I mean) have managed to construct elaborate machines that execute strategies for their self-propagation. We call those machines bodies, and the strategies include surprising ones like altruism.

The limitless variety of bodies and strategies all started with one or a few self-replicating molecules, which soon spawned mutants, which then competed with each other, and here we are.

But why limit the discussion to self-replicating molecules? What if the replicating units were ideas?

Everything we have seen about genes would apply to the replication of ideas. Ideas would mutate as they were passed from one body to the next. The mutants would accrete strategies for increased replication. The survival of host-bodies would be of little consequence compared to the survival of copies of the ideas. Ideas might form alliances to reinforce each other.

And this is exactly what we see. Ideas are passed down in a culture just as genes are transmitted through a population. Some ideas are beneficial. Others can only be called infectious.

Sometimes we say that an idea “takes on a life of its own” and that’s a very apt description.

As Dawkins puts it, “Just as genes propagate themselves in the gene pool by leaping from body to body via sperms or eggs, so memes propagate themselves in the meme pool by leaping from brain to brain in a process which, in the broad sense, can be called imitation. …memes should be regarded as living structures, not just metaphorically but technically. When you plant a fertile meme in my mind you literally parasitize my brain, turning it into a vehicle for the meme’s propagation in just the same way that a virus may parasitize the genetic mechanism of a host cell.”

I’ll illustrate using the Christian religion, since I’m familiar with it.

Like any religion or philosophy, Christianity is not just one meme, but a constellation of them. Each of the 10 Commandments is a meme, the virgin birth is a meme, the resurrection is a meme, and so on. These memes ride together on the chromosome we call the Christian faith, in symbiosis.

Each of these memes spawns diverse mutations over time, and thus diverse strains of Christianity arise. The faith now occupies many niches in the ecosystem of ideas, very much like species have evolved to occupy physical niches. Just as strains of animals diverge through evolution so much that they can no longer mate with each other, different branches of Christianity have split so completely that some do not recognize others as Christian.

Sometimes, the Christian chromosome has been crossed with other world-views, resulting in syncretic religions like Santeria.

Let’s look at one of the Judeo-Christian memes: life after death. This one has mutated considerably. It all started with the concept of Sheol — a sleepy, dreary sort of place to which we  all descend at death. Even the patriarch, Jacob, expected to go there (Genesis 37:35), and so could the wicked (Numbers 16:33). God was there (Psalm 139:8) but its denizens were unaware of him (Psalm 6:5). It was a place of “no activity or planning or knowledge or wisdom” (Ecclesiastes 9:10). Basically, you were asleep.

Asleep? So who cares?

Everybody goes there? So why should I worry about it?

Obviously, the Sheol meme does not have much replicating power. We should not be surprised that the Jews who believed it were not proselytizers. But the meme mutated and over the next few hundred years the mutations overwhelmed the original in the meme pool.

The idea of godly people being rewarded by an eternity of bliss, but the ungodly suffering eternal separation from God, was one of those mutations. The reason this meme was more powerful was that it contains the motivation for its own replication. You want to tell your loved ones how to avoid hell and go to heaven.

Further mutations arose. Eventually the Catholic church enumerated 7 deadly sins and specific punishments for them. Pride was the most serious, and punishable by breaking on the wheel in hell (warning: very disturbing content). Lesser sins got you boiled in oil, thrown in snake pits, smothered in fire and brimstone, etc.. How far we have wandered from the sleepy meme of Sheol!

Some liberal branches of Christianity carry another mutation, which sees heaven and hell as conditions we create for ourselves here on Earth.

The spread of these memes is only tangentially related to their truth or falsehood. As Dawkins establishes earlier in the book, any self-replicator will be successful to the extent that it possesses three characteristics: longevity, fecundity, and copying-fidelity. By all three measures, fundamentalist faiths have the upper hand.

A meme that emphasizes a life-long “relationship with God” and severely penalizes apostasy will have a longevity advantage over memes that encourage a live-in-the-moment approach. We have already seen that the hell meme is more fecund than the less fearsome ideas about the afterlife. A faith based on a foundational text has an inherent copying-fidelity advantage over a faith that extols free inquiry.

If truth or falsehood have little to do with the success of a meme, what is to become of us? In a culture that has a strong dose of the rationalism meme, another meme that can be shown to be ridiculous may eventually be shamed into extinction, but one thing on which we can all agree is that people (other people) have a nearly unbounded ability to believe the ridiculous.

Some memes have done their human hosts much good. The meme of participatory democracy has unarguably improved human well-being where it has taken hold. The technique of mass production is also a meme, and has vastly improved our standard of living — while, some would say, nearly extinguishing other beneficial memes.

Will the good memes or the bad memes prevail? That is an open question, and I’ll speculate on it in an upcoming post. [Done, here.]

The Selfish Gene – Part 4

<< Previous in this series: The Selfish Gene – Part 3

Chatper 10: You Scratch My Back, I’ll Ride Yours

Continuing to blog my way through Richard Dawkins’ classic, The Selfish Gene, I’ve arrived at Chapter 10, which is about animals living in groups.

Most fascinating for me was how the Selfish Gene idea relates to altruism in the social insects classified as hymenoptera. What makes these bugs such oddballs is their asymmetric degrees of genetic relatedness. Quoting Dawkins:

“A hymenopteran nest typically has only one mature queen. She made one mating flight when young and stored up the sperms for the rest of her long life — ten years or even longer. She rations the sperms out to her eggs over the years, allowing the eggs to be fertilized as they pass out through her tubes. But not all the eggs are fertilized. The unfertilized ones develop into males. A male therefore has no father, and all the cells of his body contain just a single set of chromosomes (all obtained from his mother) instead of a double set (one from the father and one from the mother) as in ourselves. …

“A female hymentoperan, on the other hand, is normal in that she does have a father…”

A male gets 100% of his genes from his mother, so the Selfish Gene hypothesis neatly explains why males sacrifice all for their queen. From the standpoint of a male’s genes, saving the life of his queen is exactly equivalent to saving his own life. In fact, it’s better because she will continue to pump out more copies of those genes for the rest of her life.

Things get even more interesting with the sterile females (the “workers”). On average, a female shares 3/4 of her genes with her sisters. That’s because they have identical genes from their father (remember, he only had one set of genes to contribute), and an average 1/2 of their mother’s genes in common.

Although sisters share 3/4 of their genes, their mother passes only 1/2 of hers to her daughters (the father contributing the other half).

Thus, females are more closely related to their sisters than to their offspring!  Selfish gene theory correctly predicts that they would be willing to forego having babies, and devote their lives to caring for each other instead.

If you want to read more about this, you can google eusociality. Wikipedia’s article has a helpful section on its evolution. (They observe that Darwin was puzzled at how it could have evolved, but correctly anticipated that a rationale might be found someday. That day arrived with the synthesis of Mendel’s discoveries in genetics and Darwin’s ideas of natural selection.)

There’s much more in this chapter, including birds who are willing to call a predator’s attention to themselves by raising an alarm to their flock, ants and aphids in symbiosis, and animals that invest energy grooming each other.

The upshot is that many examples of altruism that seem to be contrary to evolution are anything but.

>> Next in this series: The Selfish Gene – Part 5

The Selfish Gene – Part 3

<< Previous in this Series: The Selfish Gene – Part 2

Sperm Meet Egg

Sperm Meet Egg

Continuing to blog my way through Richard Dawkins’ book, The Selfish Gene, I’ll summarize the 3 chapters that lead up to the stunning conclusion.

Chapter 7 – Family Planning

We might think that animals would have as many offspring as possible in order to maximize the propagation of their genes, but evolution is smarter than that. If an animal has more children than it can care for, it may end up with fewer surviving progeny than if it had had a more manageable number. So, it may make sense for it to limit its offspring, and that is exactly what we find in many species — particularly species that must time and energy caring for their young.

Chapter 8 – Battle of the Generations

Every parent wants all of her children to have what they need to thrive; every child wants more than his fair share. This chapter explores the strategies various species have evolved to resolve that conflict. Through it all, as usual, the real master of ceremonies is the gene, which apparently programs both parent and child to create as many copies of itself as possible.

I’ll quote an example. “Consider the question of when weaning should take place. A mother wants to stop suckling her present child so she can prepare for the next one. The present child, on the other hand, does not want to be weaned yet, because milk is a convenient, trouble-free source of food, and he does not want to have to go out and work for his living.”

That is a familiar example, but Nature has contrived a seemingly infinite number of arenas in which this type of battle takes place. Cuckoo birds outsource the conflict: the mother cuckoo lays her egg in the nest of another species. “As soon as it hatches, blindly and mechanically, but with devastating effectiveness, it throws the other eggs out of the nest” so that it has its foster parents’ attention all to himself. Cute!

Dawkins explains how all this behavior is in the service of the gene’s desire to maximally replicate.

Chapter 9 – Battle of the Sexes

I’ve always wondered how sexual reproduction could have gotten started. What good is a sperm if there is no egg?

The first step toward an answer is to observe some primitive species that are isogamous: each parent contributes half the chromosomes to the offspring, but those genes come packaged in cells that are alike. Now to quote Dawkins, who is quoting Parker:

“In the days when all sex cells were interchangeable and of roughly the same size, there would have been some which happened to be just slightly bigger than others. …[The large sex cell] would get its embryo off to a good start by giving it a large initial food supply. There might therefore have been an evolutionary trend toward larger gametes. But there was a catch. The evolution of isogametes which were larger than strictly necessary would have opened the door to selfish exploitation. Individuals who produced smaller than average gametes could cash in, provided that they could ensure that their gametes fused with extra-big ones. This could be achieved by making the small ones more mobile, and able to seek out large ones actively. The advantage to an individual of producing small, rapidly moving gametes would be that he could afford to make a larger number of gametes, and therefore could potentially have more children.”

Men and women have been negotiating the behavioral implications of this ever since. A woman can only bear one child every year or so, but a man can father hundreds of children in that time. A woman is motivated to ensure that all of her relatively rare children survive and for this she needs the help of her mate. The man, on the other hand, can afford a quantity-over-quality strategy. If the men were to have their way, there would be many babies, but they would be malnourished at best. In the most successful human societies, the women have managed to tame the men, refusing sex unless they are sure their men will be around for the long haul.

Other species that must care for their young have evolved similar solutions. For example, the female might require a long courtship ritual or a fresh-built nest as proof of her suitor’s devotion.

It’s fascinating to think that the devotion of the male is the long-term result of the sperm’s selfish exploitation of the extra resources in the egg.

>> Next in this series: The Selfish Gene – Part 4 (Chapter 10)

The Selfish Gene – Part 2

<< Previous in this Series: Part 1 (Chapters 1 through 3)

Continuing to blog an unfairly brief summary of each chapter in Richard Dawkins’ famous book, The Selfish Gene

Chapter 4 – The Gene Machine

To promote their survival, genes have engineered bodies. They control their bodies much like a computer programmer controls a chess game through his software: he builds in some behaviors that he hopes will lead to victory, but he cannot affect every move.

A chess program appears to behave purposefully, but it is not as conscious as it seems. Bodies are only purposeful in the same sense. Still, such behavior is indistinguishable from what some would call “real” purpose, so what’s the difference? (I have blogged about this before, in the series on artificial consciousness.)

Chapter 5 – Aggression: stability and the selfish machine

It is naive to think that “survival of the fittest” means survival of the most aggressive and ruthless. Game theory demonstrates that constant aggression can expend too much energy relative to the reward. Unvarying pacifism will also be punished. The strategies that we observe in nature, such as “cooperation unless provoked,” are smarter.

As genes mutate, the ones that stumble upon ways to program their hosts for smart behavior will flourish. Those that program either hyper-aggressive behavior that invites retaliation, or wimpy behavior that is taken advantage of, will be at an evolutionary disadvantage.

Chapter 6 – Genesmanship

When we say that the unit of evolution is the gene, we do not mean one particular copy of the gene, but all copies. If I have three children, and each one’s genes are half mine, it pays for me to sacrifice my life for their sake. I save one and a half copies of my genes while sacrificing only one copy. Even if I have only one child, it might still pay, for that child has a longer reproductive future than I do. It might even pay to save several more-distant relatives, who each carry a smaller fraction of my genes.

Of course, we usually have neither the time nor the training to perform such calculations. Compounding the difficulty, we don’t always know who has our genes and who doesn’t.

However, we have apparently evolved rules-of-thumb, for this calculated altruism is exactly what we observe. Even though we think we believe that “all men are brothers” the reality is that we are more altruistic toward our real brothers than toward people of different nations or races.

>> Next in this series: Part 3 (Chapters 7 through 9)