Thoughts on Sex, Gender and Evolution.

Marianne J. Legato, M.D.* *With A Lot of Help from

Charles Darwin et al.

So we’ve “Cracked the Genetic

Code”

and “Defined The Human

Genome”

So?

What’s a chromosome?

What’s a gene? How does it work?

What’s a “mutation?”

Who exactly wasCharles Darwin?

What did he say?

(And why should we care?)

1809-1882

What makes us

male or female?

XX

X Y

Do we need two sexes?

(The Y chromosome only arrived

on the scene about 300,000,000 years

ago.)

Does Sex Impact Gene Expression?

“Thousands of genes show sexual dimorphismin liver, adipose, muscle and the brain: theyexhibit highly tissue-specific patterns of expression.. “*

“We saw striking and measurable differencesin more than half of the genes’ expression patternbetween males and females. We didn’t expect that.no one has previously demonstrated this geneticgender gap at such high levels.”**

*Yang et al. Genome. 2006 **Thomas Drake, C0 investigator

Does every cell in our body have a sex? Or are some parts of us androgynous?

Does every gene work the same wayin men and women?

So do we have (and why do we need) sex-specific tissues and organs? (I think wedo, and if you believe Darwin, it equips us perfectly for the environment. )

What are genomic scientists

doingworrying

about saying

What Scientists are Doing

• Taking genes out and inserting others

• Making biologic specimens capable of reproduction

• Giving us a precise picture of who we are and the possibility of changing it.

Evolution is no longer “natural selection”.With the advent of

genetic engineering,we can- and are-

changing very natureof created life.

Imagine:

Human cloning

Engineering the characteristics of new(human?) beings prepared for specificfunctions (like war, for example)

Prolonging the life span indefinitely

Creating new biological systems capableof reproduction (and if this is so, alsoprobably capable themselves of evolution)

Genomic Science and Sex• Will it be an advantage

to retain two sexes?

• If we eliminate biological sex in new forms of life before we understand the nature and extent of its expression on genes, what will be the consequences to form and function?

• Does the study of the impact of sex on gene expression deserve more attention?

What are scientists worrying about?

Consider the Impact OfGenomic Science On

• The environment

• Economics

• The nature and number of living beings

• The redistribution of power (planned and unplanned)

"Ever since the discovery of nuclear fission, the possibility of powerful explosives based on it had been very much in my mind, as it had in that of many other physicists. We had some understanding of what this might do for us in the war, and how much it might change the course of history.”

“I chide Goldblatt* for the incredible naiveté he and the Defense Sciences Office displayedin not thinking its plans to enhancehumans would arouse controversy….didn’t it occur to anybody that youwere playing with fire?”

Joel Garreau(in Radical Evolution)

*Michael Goldblatt, former head of the Defense Science Office

What Scientists are Saying

• We are changing the rate and mechanisms of the evolution of living things profoundly.

• If there is a choice between preserving the earth in a viable state or continuing the human race, we will probably opt to continue the race.

“My guess is that if the question of human extinction isever posed clearly, people will say that it’s all very well to say we’ve been a part of nature up to now, but that at thisturning point in the human race’s history, it is surely essential that we do something about it; that we fix the genome to get of ridof the disease that’s causing the instability, if necessary, we clonepeople known to be free from the risk, because that’s the only wayin which we can keep the human race alive.

A still, small voice may at that stage ask, but right does thehuman race have to claim precedence for itself. To which my guess is the full-throated answer would be, sorry, the humanrace has taken a decision, and that decision is to survive. And,if you like, the hell with the rest of the ecosystem.”

Sir John Maddox, Former editor of Nature

Prometheus, who gave men fire.