Some scientific vocabulary

A comment left to a previous post runs,

People who bewail the assault on teaching evolution yet enthuse the teaching of Gaia amuse me.

As stated, it's certainly an inconsistent approach. However, another reader mentioned another possible interpretation. This might be the result of ongoing confusion between the gaia hypothesis and the Greek goddess Gaia.

Science has a habit of co-opting word and phrases for its own technical meanings. Take, for example, "mitochondrial Eve".

The mitochondria in our cells have their own DNA, which is independent of the DNA in our cell nuclei. Furthermore, mitochondria are inherited only from the female parent. There's just no room for any in the sperm cells.

Using statistical methods, we can work out how far in the past the common ancestor of all the human mitochondria on this planet must have lived. I won't go in to these methods, but they exist, and are pretty well accepted.

Calling this hypothetical ancestor "Eve" proved an irresistable temptation. This does not mean she was actually named "Eve" (Or "Havah"), or that she had children from someone named Adam, or that one of her sons killed the other and was banished to wander in lands to the east, or...

It doesn't even mean she was the first human, or the only human female living at the time. The world's human population could have been as large then as it is now, and there would still have been only one woman whose line survived to this day. And if you did this test again a thousand years from now, one of her descendents would be the mitochonrial Eve, as the lines descended from the other descendents would have died out in the mean time.

This is a sort of "poker hand" result. If I deal you a poker hand, you will get only one of 2,598,960 possible hands. But that's the case which ever hand you actually got. Of whatever number of women that were living at the time of our mitochonrdrial Eve, one of them was going to be the winner of the lottery, and be our mitochondrial Eve. There's no reason to believe that one is in any special.

And there's no reason to believe there's any relation between the mitochondrial Eve and the biblical one.

The casual use of the term "design" has been decried in discussions of biology and evolution. The problem is, it's far less awkward than more precise descriptions of what biologists mean when they use the term. The fact that the fallacy of amphiboly can be applied to it is not necessarily a reason to stop using the word.

And when Lovelock came up with the Gaia hypothesis, I don't think he was seriously advocating there was an intelligence looking over the planet and keeping it in balance. He was proposing that living systems react to changes in such a way as to mitigate their effects.

It's not too far-fetched to suppose this is one more trait that would be selected for in evolution. Just as symbiotes will co-evolve, developing traits that make themselves better suited for life with each other, so whole systems might evolve traits that allow them to resist the impact of change in the environment.

Gaia need not be a Greek Goddess, mitochondrial Eve did not necessarily give birth to a mitochondrial Cain and Abel, calling something a design doesn't mean there had to be a designer, and calling something a scientific law doesn't mean there had to be a scientific legislature.