Ancestral homes - the long view

Tamakore

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Maori Irish French Scottish English
Y-DNA haplogroup
R1b-L21 DF5>BY154246
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J1c3b2
Where were my ancestral places of origin, my ancestral homelands? On a timescale of hundreds of years, I could name maybe five countries. On a timescale of thousands of years, I could name a few regions in different parts of the world. But what if I take a longer view, a timescale of millions of years? Before about 60,000 years ago the overwhelming majority of my ancestors (98%) lived in Africa. So, is Africa my ultimate place of origin? Well, the oldest stem simian fossil (Altiatlasius) was found in Africa, dated to around 57 million years ago. So, my stem simian, monkey and ape ancestors probably lived in Africa for about the last 60 million years. The mere 60,000 years they lived outside of Africa is just 0.1% of that time.

However, my ancestry goes back much further than 60 million years. The consensus seems to be that placental mammals evolved in the northern supercontinent of Laurasia. Combining plate tectonic and fossil evidence, my ancestors probably lived in Laurasia for around 115 million years (175-60 mya). Between about 335 and 175 mya Laurasia was joined to Gondwana in the supercontinent of Pangaea. It was during that 160-million-year time period that my reptile, stem mammal and true mammal ancestors evolved. At the beginning of that period my amphibian ancestors gradually became terrestrial. Before then my fish, worm, sponge and single-celled ancestors lived in the sea for about 3.5 billion years.

So, my ultimate place of origin, for over 90% of the history of my ancestors, is the global ocean. Over three billion years ago the world was almost all ocean, with no continents and just a few volcanic islands. So, it seems I'm basically a sea creature and latter-day landlubber. By the time my ancestors emerged from the water onto land they already had a bony endoskeleton, and complex nervous, reproductive, circulatory, digestive and respiratory systems. They had our sense organs and four limbs with five digits at the end of each limb. They haven't changed much since.
 

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