Men Are From Mars Women Are.....

Maybe, but I like this description of sex differences too:

Some would deny there is a deep difference. Some would psychobabble about a nurturant sex and a competitive sex. Geneticists would point to the XX and XY chromosomes, economists to the relative parental investments in offspring, veterinary students (and others who go around peering between animal legs) to the shape of the creatures genitals. Freudians, fundamentalists and sexual politicians could add their own ideas.

But from the perspective of organelle conflict, all these criteria (in so far as they are valid) are superficial. They specify things that derive from the deepest of the sex differences. Sex chromosomes, genital shape, reproductive investment and perhaps even personality all arguably follow from the resolved conflict of the organelles. The deep nature of maleness is to eject organelles from reproductive cells; the deep nature of females is to keep them.

Great! Males throw stuff out, females like to collect things. Didn't we all know that! These days I am in a mood for reaching out for a book from my shelf and rereading a passage or two. This one is from Mark Ridley's The Cooperative Gene. I highly recommend the book. It makes you think about the deep general features that all multicellular life share.

One of these features is anisogamy which is sexual reproduction involving reproductive cells or gametes of unequal size. The evolution of the eukaryotic cell initiated through a merger of two bacterial cells over a billion years ago made complex life possible, but the merger came with its own baggage, literally. The merged cell had two independent genomes. This was a situation with a potential for conflict between the two genomes. One analogy that helps is to think of a corporate merger which creates two independent management teams. It won't work. They will start undermining each other. One team has to go or turn submissive.

Evolution changed the eukaryotic cell through such mechanisms. Over time one genome ceded control by transferring most of its genes over to the other genome. This cell with the smaller genome evolved into the organelles; mitochondria (and chloroplasts). Human mitochondria have 37 genes. Ancestral mitochondria probably had 2500 genes a figure typical of bacteria. So over 98 percent of mitochondrial genes have been transferred or lost during evolution. Transfer of genes was one solution to genomic conflict. But sexual reproduction created another problem. It brought together two sets of the remaining organelle genes in one cell after fertilization. So the problem of organelle genomic conflict remained.

The evolutionary solution was for one type of reproductive cell to eject its organelles before fusing with the other type. The ejector gamete became the smaller sized sperm and the gametes which kept its organelles became the eggs. Ridley argues that sex differences follow from this great fundamental divergence.

Evolution is a quirky process. The specific evolutionary pathway taken by lineages is contingent upon historical and developmental constraints. Evolution develops one on one solutions to changing ecological pressures. But early in the history of multicellularity, the biggest limiting factor was within.

Sexual reproduction, gender and meiosis were evolution's across the board general solutions that enabled life to cross a threshold of complexity. You can think of this as the evolution of evolvability. I like big themes like the one presented in the book. This is a very readable account of various types of genomic conflicts and the ingenious devices that evolved through natural selection that minimized conflict.

I mean who would have thought that the evolution of gender helped resolve a conflict :-)

Is there a lesson here for humanity? Sure, and here is my prescription for harmonious relations between men and women. Let women keep all the stuff they want. Men, don't to try to argue, cajole, plead, sulk or throw a tantrum. It won't help. Females are good at keeping things. They have had a lot of practice. They have been doing it for more than a billion years.

The Geology Haiku Meme

Announcing the Geology Haiku Meme

deep in a bioreef
a Permian story
calcite dripstones tell

Respond Geobloggers!

Rules: Three lines and a max of seventeen syllables. Use of kigo, which is the traditional reference to a season, may be substituted by a reference to a geological period. The use of kireji, which is a word that serves to give structural support to the verse is not widely practiced in English haiku, so you may give that a pass.

Leave a link in my comments section and I'll post a collection of Geology Haiku links soon :-)

See: A Collection of Geological Haiku

That's Why North Indians Cough More

A stunning image of north India taken by the the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Image was taken on October 30 2008.



Source: NASA Earth Observatory

The haze seen has many causes. Urban pollution, big fires (red dots) and small fires lit for cooking and maybe a sandstorm. Is this worse than Los Angeles at its worst? With winter setting in the northern parts of the country the air quality will deteriorate even further as millions of charcoal and wood fires are lit for warmth. Respiratory problems increase dramatically in the winter in north India.

India faces a frightening challenge of improving air quality both in urban and in rural settings where indoor pollution is a major health hazard. The government has launched the National Action Plan for Climate Change (15 Mb) with separate missions aimed at providing clean energy. Even with a sense of urgency it will likely take a couple of decades to unfold. In the meantime how do you provide alternatives to ten's of millions of people who light up coal and wood fires inside their houses? The National Action Plan besides its focus on large scale clean power generation, urban pollution, sea-level rise and so on, must also provide strong incentives to companies involved in producing low-cost clean energy solutions for rural India.

More Jurassic and Cretaceous Reminiscences

Another passage about the Jurassic oolite from Simon Winchester's The Map That Changed The World.

Within the oolitic horizon there are countless variations-of color (gray, orange to ochre to pale scarlet) and fineness of texture, size of oolith, and width of banding and bedding plane.

I chanced during my journey upon a roadside quarry near the village of Northleach, and the ebullient owner happily showed me around, pointing out with delighted pride the different colors and thicknesses of his rocks, and the uses he could make of the various types.

That triggered a lot of memories for me. Not of the Jurassic but of the Cretaceous of south India. I had just started to take geology seriously and a bunch of us outdoor enthusiasts decided to go on a fossil hunting trip to the continental-marine Cretaceous sedimentary basin of southeast India.

These basins formed in the early Cretaceous as India which was part of the southern hemisphere super continent Gondwanaland broke away from Australia and Antarctica. The map below shows the paleo geography of early Cretaceous. Notice the southern hemisphere location of India at that time and that India has rifted away from Australia and Antarctica and now has a distinct eastern continental margin.



A number of NE-SW trending basins formed on this rifted continental margin of eastern India. The map below shows these eastern Mesozoic-Cenozoic basins. The Cauvery basin which I visited is the southern most of the basins.

Source: Geotimes

All these basins have offshore extensions in the Bay of Bengal. Today these Cretaceous eastern basins have acquired an economic importance with the potential of hydrocarbon deposits especially in the offshore portions of these basins. Reliance Energy recently discovered oil and natural gas from the deep water Cretaceous section of the Cauvery basin and more discoveries of oil and gas are likely.

But in those early college days my interest was palaeontology and fossils. We had discussed the trip with some palaeontologists from the graduate geology department in Pune and so had all the good fossil bearing localities on map. Every day we explored the terrain around the village of Ariyalur which was our base and is located in a rather remote rural portion of Tamil Nadu. One afternoon we got a bit frustrated trying to find a quarry. As we walked on a man on a bicycle approached. Seeing we were distant city dwellers he stopped and started chatting to us proudly in English, eager to show off his vocab. We asked him about fossils and he replied grandly:

Yes Yes, just two miles down this road, there is quarry which is notorious for fossils!

Now as far as I know these long dead Cretaceous beasts entombed in clays and marls have never harmed a human. I guess he meant famous, but maybe the man was indicating to us that the quarry owner is a psycho?

That made our day. With much merriment and anticipation we reached the quarry and found a not so notorious but like Simon Winchester's quarry owner a rather jovial and ebullient personality. He showed us around and gave us samples of claystones from the early Cretaceous littoral facies which contained plant fossils. These were in the form of delicate impressions pressed on clay and you could see clearly the structure of the leaf. A rare treasure which I promptly lost somewhere by the time I graduated.

Geology field trips often throw up these kind of special moments.

That Desperate For A Obama Victory

Overheard at Obama Victory Party:

"Yay, daddy! Now we don't have to move to Canada!"

Tip: Overheard Lines