It is often assumed (see first post below) that human evolution relied on new mutations. Whilst not doubting that this process can occur, why is it necessary to assign it any major significance? When we migrated out of Africa, all the pre-existing genes for adaptation to warm climate would have become rarer, and those useful for cold climates would have become commoner. This can all be explained simply by genomic reorganisation without needing to assume any new mutations.
"Harmful genetic mutations may be less common than we thought
April 13, 2018 2.40pm [The Conversation]
Jess Buxton Senior Lecturer in Medical Genetics, Kingston University...
We are all mutants. Every characteristic that defines our species is the result of a genetic mutation somewhere in the history of evolution. And the same is true for every other organism on the planet. Yet more often than not we think about mutations as bad, leading to disability or disease. So how often are these changes to DNA harmful and how many of them are potentially helpful?"
From a population genetics point of view, both are likely to have occurred. Individuals with allelic variants that provided more fitness in colder climates would do better and produce mroe offspring, thus those allelic variants would become over represented. But given the time frame of 10s of thousands of years, new mutations would likely occur as well to create new variants upon which selection can act. PS, I would not call this genomic reorganisation, as this implies genome schuffling. Selection works by favoring specific allelic variants of genes in the population, not by reorganizing the genome.
Last Neanderthals went extinct 35 KYA. Most of us have 1-4% Neanderthals DNA. May be the mutation or other facts can create new variants in Human or lost. Be optimistic, "Harmful genetic mutations may be less common than we thought ".Thanks Dr. Anthony.
"I would not call this genomic reorganisation,"
I think by far the main motor and selective force in human evolution was the non-random purging of masses of deleterious genes during periods of high infant mortality. Only the healthiest, most competent and intelligent mothers were able to feed their infants properly and keep them alive. I would call this genomic reorganisation. Is there a better name? Gene dumping?
- Badges
- Science topic
- Similar topics
- Biological Science
- Genetics