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What makes us human?

Different animals and plants have different numbers of genes and chromosomes that together make up their genome.  Many are far more complex than humans.  The 32 thousand  human genes are organised into 23 pairs of chromosomes within each of our cells.  But the protein-coding genes, that differentiate us, form only a fraction (about 1.5%) of the instruction and memory data that is stored in DNA. The remainder, coding for other aspects of cell chemistry, seems to be administrative overhead.

When human girls are born, they have about a million eggs in each of their two ovaries, nestled in fluid-filled cavities called follicles. But this number declines quite rapidly so that it is depleted by the time of menopause (usually before 50 years of age). Unless fertility treatment is in use, just one or sometimes two of these (apparently randomly selected) ova descends from the ovaries each menstrual period - down the woman's fallopian tubes where it (or they) may become fertilised if the woman has recently engaged in coitus (had 'sex').

As in vitro fertilization (IVF) demonstrates every day; we now understand that a unique version of your father's genome was injected into your mother's egg by just one of his millions of spermatozoa. So that when the two genomes merged a doubly unique cell, that became you, was the result.

Our genes, that are encoded in their DNA, come in equal proportion from both parents.  Unless we have an identical twin, resulting from division of the zygote (see below) after fertilisation, each of us is genetically unique; our genetic identity determined by that successful fertilisation. 

 

 

human reproduction
Human Reproduction - Click here to Expand

 

Within our species we are said to be of Caucasian or Asian or African appearance, to have dark or fair complexion and so on, and possibly to bear a ‘family resemblance’.  These traits are due to the particular gene variants we have inherited from our parents.

These have been passed down to us, with regular variations, from parent to child, and through many ancestor species, since life began on the planet. And all plants and animals on Earth belong to a single family because we all inherit the same system of reproduction from one original replicating cell, our last universal common ancestor (LUCA) 3.5 to 3.8 billion years ago.

 

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Travel

Argentina & Uruguay

 

 

In October 2011 our little group: Sonia, Craig, Wendy and Richard visited Argentina. We spent two periods of time in Buenos Aires; at the start and at the end of our trip; and we two nights at the Iguassu Falls.

Read more: Argentina & Uruguay

Fiction, Recollections & News

Australia Day according to ChatGPT

 

I've long been interested in the advent of artificial intelligence (AI). It's a central theme in my fictional writing (The Cloud and The Craft) and is discussed in my essay to my children 'The Meaning of Life' (1997-2017). So, I've recently been exploring the capabilities of ChatGPT.

As today, 26 January 2024, is Australia Day, I asked ChatGPT to: 'write 1000 words about Australia Day date'.  In a few minutes (I read each as it arrived) I had four, quite different, versions. Each took around 18 seconds to generate. This is the result:

Read more: Australia Day according to ChatGPT

Opinions and Philosophy

Energy and a ‘good life’

 

 

 

Energy

With the invention of the first practical steam engines at the turn of the seventeenth century, and mechanical energy’s increasing utility to replace the physical labour of humans and animals, human civilisation took a new turn.  

Now when a contemporary human catches public transport to work; drives the car to socialise with friends or family; washes and dries their clothes or the dishes; cooks their food; mows their lawn; uses a power tool; phones a friend or associate; or makes almost anything;  they use power once provided by slaves, servants or animals.

Read more: Energy and a ‘good life’

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