|
Register | Sign In |
|
QuickSearch
EvC Forum active members: 65 (9164 total) |
| |
ChatGPT | |
Total: 916,913 Year: 4,170/9,624 Month: 1,041/974 Week: 368/286 Day: 11/13 Hour: 0/0 |
Thread ▼ Details |
|
Thread Info
|
|
|
Author | Topic: Question about evolution, genetic bottlenecks, and inbreeding | |||||||||||||||||||||||||||
harry Member (Idle past 5498 days) Posts: 59 Joined: |
Hi
I am a evolution enthusiast but I am struggling with one of the concepts. When a species is isolated, goes through a bottle neck, or a small amount of one species is divided from the rest and branches into a new species, what prevents inbreeding having to much of a negative impact to the species survival? Surely the time it takes variety in the smaller gene pool takes longer than it would for inbreeding to have an effect. Educated researched answers please! No nonsense about this is a disproof of evolution, or half baked answers please!! Edited by Adminnemooseus, : Added the ", genetic bottlenecks, " to topic title
|
|||||||||||||||||||||||||||
Adminnemooseus Administrator Posts: 3976 Joined: |
Thread moved here from the Proposed New Topics forum.
|
|||||||||||||||||||||||||||
lyx2no Member (Idle past 4746 days) Posts: 1277 From: A vast, undifferentiated plane. Joined: |
When a species is isolated, goes through a bottle neck, or a small amount of one species is divided from the rest and branches into a new species, what prevents inbreeding having to much of a negative impact to the species survival? Nothing. The subgroups risk of extinction is inversely proportional to it size, though this is mitigated to some degree by an increase in genetic drift. The total research involved in this statement is a memory from something I read rar, rar, rar somewhere, rar, rar dealing with cheetahs, rar, rar Welcome, Harry. Edited by lyx2no, : Add some rars. Genesis 2 17 But of the ponderosa pine, thou shalt not eat of it; for in the day that thou shinniest thereof thou shalt sorely learn of thy nakedness. 18 And we all live happily ever after.
|
|||||||||||||||||||||||||||
harry Member (Idle past 5498 days) Posts: 59 Joined: |
Ok, so I kinda knew that.
So, I am struggling to wrap my head fully around common ancestor and how that ties in with inbreeding. So one little monkey, has fun time with another monkey, and they have 2 baby monkies, monkey one goes on to become humans, the other goes onto become chimpanzees. So monkey 1 is our concestor with chimps. however, even if monkey 1, were to mate with 5 females, the grandchildren would all be very inbred. Can somebody draw me a tree of how 1 ancestor gets enough genetic material to mix it up? Because surely it can't get that many from the species it split with, or it would not be the common ancestor, and the whole process would start again. Thanks for the welcome!
|
|||||||||||||||||||||||||||
Rahvin Member Posts: 4046 Joined: Member Rating: 8.3 |
Ok, so I kinda knew that. So, I am struggling to wrap my head fully around common ancestor and how that ties in with inbreeding. So one little monkey, has fun time with another monkey, and they have 2 baby monkies, monkey one goes on to become humans, the other goes onto become chimpanzees. So monkey 1 is our concestor with chimps. however, even if monkey 1, were to mate with 5 females, the grandchildren would all be very inbred. Can somebody draw me a tree of how 1 ancestor gets enough genetic material to mix it up? Because surely it can't get that many from the species it split with, or it would not be the common ancestor, and the whole process would start again. You're confused because that's not the way evolution works. You're close, but "common ancestor" does not imply individual. Evolution occurs over populations. So, Population A is comprised of 20,000 individuals. Something happens, and that population splits into two daughter populations - Pop. B and C, each with around 10,000 individuals. These two populations, if they do not interbreed, will continue to evolve in divergent pathways. Population B could be the ancestors of humanity, while Population C could be the ancestors of chimpanzees. No inbreeding required. The separation of populations can happen for any number of reasons - natural disasters, migration due to overpopulation, what have you. Edited by Rahvin, : No reason given.
|
|||||||||||||||||||||||||||
harry Member (Idle past 5498 days) Posts: 59 Joined: |
I got the impression from the text books that a common ancestor was an individual.
|
|||||||||||||||||||||||||||
harry Member (Idle past 5498 days) Posts: 59 Joined: |
I see, I have been getting common ancestor confused with Most recent common ancestor.
Thanks for the help guys!
|
|||||||||||||||||||||||||||
Rahvin Member Posts: 4046 Joined: Member Rating: 8.3 |
I got the impression from the text books that a common ancestor was an individual. That's a mistaken impression. As I said, evolution happens over populations, not individuals. It's an incredibly slow process that happens by increments of mutations - Species X does not give birth to Species Y. Species Y is a descendant of Species X only after many generations of mutations sufficient to disallow interbreeding between the two. In each generation, the given population is able to interbreed with itself. No familial inbreeding, and no "single individual" common ancestors (Not to say that single individual common ancestors are impossible, simply that this is not typically what happens).
|
|||||||||||||||||||||||||||
harry Member (Idle past 5498 days) Posts: 59 Joined: |
quote: Yeah I am way beyond that level So there is a difference between most recent common ancestor, which is an individual, and a common ancestor?
|
|||||||||||||||||||||||||||
Rahvin Member Posts: 4046 Joined: Member Rating: 8.3 |
So there is a difference between most recent common ancestor, which is an individual, and a common ancestor? Incorrect. The most recent common ancestor is still the most recent common ancestor species, which is a population. Individuals don't even enter the picture. All of Species Y is not descended from an individual of Species X; Species Y is descended from a population from Species X.
|
|||||||||||||||||||||||||||
harry Member (Idle past 5498 days) Posts: 59 Joined: |
No that is wrong, the MRCA is not a species, I know that for sure.
Unless there is any confusion. All humans have a MRCA, we all related through one individual. So therefore there must be an individual from which all humans and chimpanzees are descended, regardless of whether that individual bred with with how ever many other monkeys. Edited by harry, : No reason given.
|
|||||||||||||||||||||||||||
bluescat48 Member (Idle past 4220 days) Posts: 2347 From: United States Joined: |
No that is wrong, the MRCA is not a species, I know that for sure. Unless there is any confusion. All humans have a MRCA, we all related through one individual. No you are confused. The MRCA is a term for the most recent common ancestor of 2 species no matter how far they are from each other. It is not a single individual but a population. The MRCA between a Homo sapiens & a Homo erectus is different that the MRCA between a homo sapiens and Pan troglodytes, and different than the MRCA between Homo sapiens and Gorilla gorilla. Similarly the MRCA of Pan & Homo has a MRCA with Gorilla. One can back and find a MRCA between Humans & Grasshoppers if one wants to go back that far. In all cases these MRCA's are a species not an individual There is no better love between 2 people than mutual respect for each other WT Young, 2002 Who gave anyone the authority to call me an authority on anything. WT Young, 1969 Since Evolution is only ~90% correct it should be thrown out and replaced by Creation which has even a lower % of correctness. W T Young, 2008
|
|||||||||||||||||||||||||||
lyx2no Member (Idle past 4746 days) Posts: 1277 From: A vast, undifferentiated plane. Joined: |
When harry introduced his second idea there was something uncomfortable in the back of my mind, as if something I intuited was questionable but I couldn't quite put my finger on it. Still you cleared it up; I held harry's idea in my head without even knowing it. Thank you both for shaking it out. It's nice to be rid of a misconception even when you didn't know it was there.
AbE: harry, are you referring to Y-Adam and Mitochondrial Eve? Edited by lyx2no, : No reason given. Edited by lyx2no, : Typo in first edit. Genesis 2 17 But of the ponderosa pine, thou shalt not eat of it; for in the day that thou shinniest thereof thou shalt sorely learn of thy nakedness. 18 And we all live happily ever after.
|
|||||||||||||||||||||||||||
Stagamancer Member (Idle past 4946 days) Posts: 174 From: Oregon Joined: |
No that is wrong, the MRCA is not a species, I know that for sure. This is true. Here's an explanation from Wikipedia:
quote: What this is saying is that if you trace a family tree back far enough, you can find an individual who everybody is related to in some way. This does NOT mean that this individual is responsible for "creating" the whole human species. So, yes, there is probably an individual to which all humans and chimpanzees can trace back to. However, this does not mean that this individual had offspring that were either human or chimpanzee. The evolution still occurred at the population level. Edited by Stagamancer, : No reason given. "There are three kinds of lies: lies, damned lies, and statistics."
|
|||||||||||||||||||||||||||
Taz Member (Idle past 3321 days) Posts: 5069 From: Zerus Joined: |
This thread reminds me of high school biology. Back then, I was a hardcore creationist who would argue for hours with the biology teacher. I remember one of the things I and many other students struggled with was this very thing you guys are talking about, that the common ancestor is a species and not an individual and that individuals don't evolve. I think part of the problem for me was I had this preconceived notion about evolution that stuff evolve by morphing. This preconceived notion of evolution is closer to what happens to Marcus Corvinus in Underworld Evolution than reality.
I think at this point I'm suppose to say god rules evolution sux.
|
|
|
Do Nothing Button
Copyright 2001-2023 by EvC Forum, All Rights Reserved
Version 4.2
Innovative software from Qwixotic © 2024