Tiny Sperm

Mice have sperm that is twice as long as elephants’. The world’s longest sperm belongs to a fruit fly. And across the animal kingdom, sperm take on extremely odd and varied shapes and sizes. The tadpole shape we most associate with sperm is not at all common outside of mammals. Rat and mice sperm can have hook-like attachments on their heads.

Some species seem to allow sperm to connect by their heads and form so-called sperm trains, these groups of sperm seem to swim faster than individual sperm.

From an evolutionary perspective this raises an intriguing question: Why are sperm so varied among different species when they all have the exact same purpose — fertilizing eggs? It turns out, the larger the species, the smaller the sperm.

Why would evolution favour such a pattern? When in comes to sperm, size matters. Longer sperm has some advantages — they are better at elbowing aside the competition. But it also takes a lot of energy to make long sperm, which larger animals can’t afford. So it’s a trade-off:

If there were no constraints on sperm production and assuming that longer sperm are advantageous, each male would probably produce lots of impressively big sperm. But in nature there are always constraints because resources and energy are not unlimited. For a testis of a given size, producing bigger sperm thus means it cannot produce as many of them (producing big sperm takes more resources, energy and time).

So, whether investing more in sperm size or in sperm number to maximize sperm competitiveness really depends on the circumstances, for example the size of the female reproductive tract. In large species, the female reproductive tract is massive compared to the tiny sperm, so sperm can easily be lost or diluted in it. Males have to compensate by transferring more sperm. Simply making longer sperm really would not make a difference in an elephant. They would have to be incredibly large. So males are better off making lots of tiny sperm.

This inverse correlation between animal size and sperm size might be a consistent pattern across the animal kingdom. Almost all animals with sperm longer than a 10th of a millimetre, he explains, weigh less than one or two pounds.

The mammal with the longest sperm? It’s not the human. That distinction belongs to the honey possum, a very small (they grow to 3.5 inches long ) marsupial that lives in western Australia. They are adorable. Their sperm is 350 micrometers (.014 inches) long.

The Emotional Factor

‘As I said before, I do not think that the real reason why people accept religion has anything to do with argumentation. They accept religion on emotional grounds. One is often told that it is a very wrong thing to attack religion, because religion makes men virtuous. So I am told; I have not noticed it. You know, of course, the parody of that argument in Samuel Butler’s book, Erewhon Revisited. You will remember that in Erewhon there is a certain Higgs who arrives in a remote country, and after spending some time there he escapes from that country in a balloon. Twenty years later he comes back to that country and finds a new religion in which he is worshiped under the name of the “Sun Child,” and it is said that he ascended into heaven. He finds that the Feast of the Ascension is about to be celebrated, and he hears Professors Hanky and Panky say to each other that they never set eyes on the man Higgs, and they hope they never will; but they are the high priests of the religion of the Sun Child. He is very indignant, and he comes up to them, and he says, “I am going to expose all this humbug and tell the people of Erewhon that it was only I, the man Higgs, and I went up in a balloon.” He was told, “You must not do that, because all the morals of this country are bound round this myth, and if they once know that you did not ascend into Heaven they will all become wicked”; and so he is persuaded of that and he goes quietly away.

That is the idea — that we should all be wicked if we did not hold to the Christian religion. It seems to me that the people who have held to it have been for the most part extremely wicked. You find this curious fact, that the more intense has been the religion of any period and the more profound has been the dogmatic belief, the greater has been the cruelty and the worse has been the state of affairs. In the so-called ages of faith, when men really did believe the Christian religion in all its completeness, there was the Inquisition, with all its tortures; there were millions of unfortunate women burned as witches; and there was every kind of cruelty practiced upon all sorts of people in the name of religion.

You find as you look around the world that every single bit of progress in humane feeling, every improvement in the criminal law, every step toward the diminution of war, every step toward better treatment of the colored races, or every mitigation of slavery, every moral progress that there has been in the world, has been consistently opposed by the organized churches of the world. I say quite deliberately that the Christian religion, as organized in its churches, has been and still is the principal enemy of moral progress in the world.’

– Denonn. L.E., Egner. R.E. Ed. 1961. The Basic Writings of Bertrand Russell London, United Kingdom: George Allen & Unwin (1962) p. 595

Bertrand Russell delivered the lecture Why I am not a Christian (of which this is an excerpt) on March 6, 1927 to the National Secular Society, South London Branch, at Battersea Town Hall.

The Little Red Book is Non-secular

In order for institutions based on Lyotardian grand narratives to flourish, such as totalitarian regimes and organised religions, a certain amount of unquestioned belief is needed. Consider the following excerpts out of the preface to Mao Zedong’s Little Red Book, published in China as the Red Treasure Book in 1964:[1]

‘Study the writings of chairman Mao, obey the words of chairman Mao and act according to the words of chairman Mao.’
– Lin Biao, Vice Chairman of the Communist Party of China 1958-1971 and Marshal of the People’s Republic of China (p. 5)

‘Over the past few years, the ‘Thinking of Mao Zedong’ has been dressed in the aura of the one and only universal truth. More so than the explicitly confessed Marxist-Leninism are the sayings and writings of Mao Zedong that are revered and studied, and are used by everyone from the professor to the melon salesman, and the marine engineer to the table tennis champion to achieve greater accomplishments.’
– Cornelis Schepel, Institute of Sinology, Leiden (p. 7)

[1] These citations were not featured in the original Chinese publication of Mao Zedong’s Little Red Book, but have been translated to English from a Dutch translation of Zedong’s most famous work, first published as Het Rode Boekje in 1967 by A.W. Bruna & Zonen and reprinted in 2005 by Forum.

Death is #2

‘I saw a thing, actually a study that said: speaking in front of a crowd is considered the number one fear of the average person. I found that amazing. Number two, was death. Death is number two? This means, to the average person, if you have to be at a funeral, you would rather be in the casket than doing the eulogy.’

Seinfeld, J. (1998). I’m Telling You For The Last Time. Broadhurst Theatre, New York: Universal Records.

The Split From Apes

Our genes start changing
13-7 million years ago

Our ancestors split from their chimp-like relatives over 7 million years ago. At first, they would have looked similar. But within their cells, change was afoot. After the split, the ASPM and ARHGAP11B genes began changing, as did a region called HAR1. It’s not clear what this did, but HAR1 and ARHGAP11B are involved in the growth of the cerebral cortex.

See other: What Makes Humans Human?

On Evidence-free Ideologies

“Today, Nazism is considered to be a political ideology; it was, however, as opposed to Fascism, a worldview, a faith.”

– Lina Heydrich