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Author | Topic: How is Natural selection a mechanism? | ||||||||||||||||||||||||||||||||||
Taq Member Posts: 8469 Joined: Member Rating: 6.0 |
It is also possible that homosexuality is a somewhat rare side effect of another attribute that is being selected for, such as group empathy, heterosexual sex drive, or intelligence. As long as the side effect remains low then the much more common effect that is being selected for will continue to maintain the attribute in the population.
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Taq Member Posts: 8469 Joined: Member Rating: 6.0 |
That has more to do with quantum mechanics than thermodynamics. As far as thermodynamics goes, if you dropped the egg into a bowl, and then lifted the bowl back to the height the egg was previously at you will have moved the system back to the entropy it had before. The energy used up in the system was the gravitational energy released during the fall.
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NoNukes Inactive Member |
Not restricted to humans. Birds can arrange fallen twigs, leaves, etc into a nest. Beavers can dam up streams. Both are examples of entropy decreases in a part of a system. Edited by NoNukes, : No reason given. Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846) I was thinking as long as I have my hands up … they’re not going to shoot me. This is what I’m thinking — they’re not going to shoot me. Wow, was I wrong. -- Charles Kinsey I never considered a difference of opinion in politics, in religion, in philosophy, as cause for withdrawing from a friend. Thomas Jefferson Worrying about the "browning of America" is not racism. -- Faith I hate you all, you hate me -- Faith
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New Cat's Eye Inactive Member
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What about a salt solution precipitating a crystalline structure? If that's not, according to your meaning, a "decrease" then dissolving the same crystalline salt structure must be... So which way is it, according to your understanding? Honestly, you haven't completely grasped the concept of entropy yet.
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CRR Member (Idle past 1030 days) Posts: 579 From: Australia Joined: |
Natural selection happens when there is differential reproductive success over multiple generations. Those that have more offspring are favoured and those with less are disfavoured. It's not necessarily the fastest or the strongest that succeed. Over 1 generation chance can play a big factor but over multiple generations it tends to even out.
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CRR Member (Idle past 1030 days) Posts: 579 From: Australia Joined: |
All of that is quite true. It's somewhat like how sickle cell trait provides some immunity to malaria. In that case sickle cell trait is a harmful mutation affecting red blood cells and malaria resistance is a side effect. In malaria prone areas at low allele frequencies the beneficial side effect is stronger than the harmful ones, but by the time it reaches 20% the harmful effects dominate. (If it's not a malaria prone area the trait provides no benefit.)
And if homosexuality is not heritable then natural selection won't work at all. AFAIK it's not heritable so no natural selection.
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Taq Member Posts: 8469 Joined: Member Rating: 6.0 |
I don't think there are specific mutations that are directly linked to homosexuality, but there rarely are for complex characteristics or behaviors. I would view sexuality as more of a spectrum and the result of many, many genes interacting, along with social interaction. What we may also be ignoring is the nurture side of the equation. Higher population density may trigger different types of social and emotional development. A good example can be found in some insect species, such as high population density turning grasshoppers into swarming locusts that includes obvious morphological changes. Homosexuality may actually serve a positive role when population densities get high by reducing competition for mates while maintaining kin selection. Of course, what we ought to do is not determined by what is being selected for or against, otherwise known as the Is/Ought problem.
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Pressie Member Posts: 2087 From: Pretoria, SA Joined: |
You forgot about those organisms who don't have a lot of offspring; yet their genes spread amongst the population in the environment which they live in. Any good summary of natural selection will include mentioning the environment... Edited by Pressie, : No reason given. Edited by Pressie, : No reason given.
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Pressie Member Posts: 2087 From: Pretoria, SA Joined: |
Let's start with genetics. Some people are born with both male and female genitalia. No choice involved. Edited by Pressie, : No reason given.
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CRR Member (Idle past 1030 days) Posts: 579 From: Australia Joined: |
[deleted duplicate message]
Edited by CRR, : No reason given.
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CRR Member (Idle past 1030 days) Posts: 579 From: Australia Joined: |
AndrewPD, has your original question been answered yet?
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