Is evolution blind?
- Thread starter AlexGTV
- 35 comments
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- BigYoSpeck
Certain evolutionary traits are selection based, such as our walking upright, the reduction in body hair from our ancestors or peacock feathers. But also within evolution any trait which would increase the odds of surviving to breading age, would over the course of generations find it self more prevalent than subjects without that trait which would lead to an exponential increase in the trait within the species population until the population was saturated with it.
Because the mutation increased their survival odds.
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- BigYoSpeck
No species has a zero infant mortality rate though. Especially not further back in time. Trace human evolution back a few thousand years and it wouldn't have been uncommon for several children in a family to not survive until mating age, giving an enormous evolutionary advantage to any born with survival increasing mutations.
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- Philippines
Death from diabetes or cancer in old age does nothing to prevent reproduction. Arthritis, tooth loss, obesity, heart attacks... none of it.
A human only has to survive for ten years or so to reproduce, given adequate nutrition, or around fourteen years without... and just twenty to thirty years to both reproduce and support their children till they can forage for themselves.
You're all thinking in terms of large populations. Humanity wasn't always a large population. There's evidence of an evolutionary turning point wherein the entire human race was down to a few thousand people. This is the turning point at which we probably became what we are now.
After that turning point, there have been other occassions in which mutations could be selected and spread, even when the human race exceeded a million heads.
Scattered tribes of humans, in groups of dozens and hundreds, or at most, thousands, have lived separated from each other for tens of thousands of years before the big civilizations arose. And in these scattered tribes, we see some of the more modern evolutionary adaptations... like the beneficial mutation of lactose-tolerance, which allowed certain tribes to drink animal-sourced milk. Which allowed them to travel further and conquer other territories. That beneficial mutation has affected much of human history, actually..
A human only has to survive for ten years or so to reproduce, given adequate nutrition, or around fourteen years without... and just twenty to thirty years to both reproduce and support their children till they can forage for themselves.
You're all thinking in terms of large populations. Humanity wasn't always a large population. There's evidence of an evolutionary turning point wherein the entire human race was down to a few thousand people. This is the turning point at which we probably became what we are now.
After that turning point, there have been other occassions in which mutations could be selected and spread, even when the human race exceeded a million heads.
Scattered tribes of humans, in groups of dozens and hundreds, or at most, thousands, have lived separated from each other for tens of thousands of years before the big civilizations arose. And in these scattered tribes, we see some of the more modern evolutionary adaptations... like the beneficial mutation of lactose-tolerance, which allowed certain tribes to drink animal-sourced milk. Which allowed them to travel further and conquer other territories. That beneficial mutation has affected much of human history, actually..
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There is a difference between evolution and adaption. Adaption is something that happens quickly to changing environment. Genes haven't much time to change through mutation let along becoming fixed in the population. Adaption is something already there in the genes of a creature ready to become active in a given situation. Adaption can often be repeated using the same environment. Ex: Lactase and Nylonase which can be repeated with the same bacteria in labs.
The problem with only a few thousand of any specie of mammals is it limits how much can be done though mutation. Bacteria benefits the most from mutations because of the rapid growth and large numbers. (even bacteria resist evolution (change) on the large scale) You still need a huge population to "find" the right mutations yet it's difficult for any beneficial mutation to become fixed in a large population. The only way for these mutation to become fixed if the rest of the population die out quickly. Yet most cases it's not as black and white as if you got this mutation you live and if not you die.
The problem with only a few thousand of any specie of mammals is it limits how much can be done though mutation. Bacteria benefits the most from mutations because of the rapid growth and large numbers. (even bacteria resist evolution (change) on the large scale) You still need a huge population to "find" the right mutations yet it's difficult for any beneficial mutation to become fixed in a large population. The only way for these mutation to become fixed if the rest of the population die out quickly. Yet most cases it's not as black and white as if you got this mutation you live and if not you die.
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