[ 3 / biz / cgl / ck / diy / fa / ic / jp / lit / sci / vr / vt ] [ index / top / reports ] [ become a patron ] [ status ]
2023-11: Warosu is now out of extended maintenance.

/sci/ - Science & Math

View post   
File: 16 KB, 515x203, facebook-ancient-05.jpg [View same] [iqdb] [saucenao] [google]
1907128 No.1907128 [Reply] [Original]

What's the word for the lowest number of individuals needed to repopulate a species?

As in, if the population drops below this number, the population would go extinct?

>> No.1907150

Two

>> No.1907156

Nobody knows for sure, but with sexual species iirc it's around 100 breeding pairs, so ~200 people. Lower than this you can survive but you get significant inbreeding.

>> No.1907159

>>1907156
Basically this, you need a certain number to avoid too much inbreeding. But I heard the number was around 1000 or so, but I don't have a source or anything.

>> No.1907161

I think it would depend on the species

>> No.1907174

humans can survive with less than 15,000 individuals,
see http://en.wikipedia.org/wiki/Population_bottleneck
it already happened before

>> No.1907181

European bison recovered from only 12 individuals, 12!! I mean, that only 1 dozen!

>> No.1907183

Maybe the word you're looking for is "minimum viable population"?

http://en.wikipedia.org/wiki/Minimum_viable_population

>> No.1907186

>>1907183

Yes, thank you. This was it.

>>1907150
Bitches don't know about my genetic diversity.

>> No.1907201

>>1907186
whell, everyone today came from only 1 male and 1 female (no, not adem and eve)

>> No.1907203

>>1907150
http://en.wikipedia.org/wiki/Allee_effect

>> No.1907209

>>1907174
>>1907128
>People can survive with less than 15,000 individuals, this has happened before.

http://en.wikipedia.org/wiki/Genesis_creation_narrative

>> No.1907212

>>1907183
That's a phrase, not a word.

>> No.1907214

>>1907201
:@ the idea that we actually have just 1 ancestor.. its told to high schoolers, because they cant grasp hard concepts. First of all we might have 1 ancestor in common in terms of population not a single organism.
2nd life emerge from a soap of molecules. the first population of organisms could be considered those capable of replication. some molecules are capable of doing this.

>> No.1907216
File: 1.26 MB, 1000x800, 1285040410460.png [View same] [iqdb] [saucenao] [google]
1907216

Bitches dont know bout my G.E.C.K.

>> No.1907219

OP here. I was just reading this:

http://en.wikipedia.org/wiki/Popular_sire_effect

Would "strict" eugenics then actually result in the opposite of what it was meant for? Say, for humans hypothetically?

>> No.1907224

>>1907214
all living humans' female line ancestry trace back to a single female (Mitochondrial Eve) at around 140,000 years ago. Via the male line, all humans can trace their ancestry back to a single male (Y-chromosomal Adam) at around 60,000 to 90,000 years ago.

Dawkins, Richard (2004). The Ancestor's Tale, A Pilgrimage to the Dawn of Life. Boston: Houghton Mifflin Company. ISBN. ISBN 0297825038.

>> No.1907231

>>1907214
>the first population of organisms could be considered those capable of replication

We're talking about humans here. A single celled organism is not a homo sapien. Ancestry can be traced back to one male and one female.

Don't tell the christfags or they'll be all "I TOLD YOU SO LOLOL"

>> No.1907246

>>1907231
Id like to hear them explain how they matted if adem lived 50 000 years after ave.

>> No.1907250

>>1907201
Yes, in addition to EVERY SINGLE ONE OF THEIR ANCESTORS. Everyone came from other people who lived at that time ALSO, but there are individuals who we ALL descended from.

>> No.1907265

>>1907224
>>1907224

Mitochondrial Eve is the most recent common matrilineal ancestor, not the most recent common ancestor (MRCA). Since the mtDNA is inherited maternally and recombination is either rare or absent, it is relatively easy to track the ancestry of the lineages back to a MRCA; however this MRCA is valid only when discussing mitochondrial DNA

fuck you and dawkins misinformation

>> No.1907272

>>1907231
>>1907224
lol got pwned right here

>>1907265

>> No.1907281

one. bacteria.

>> No.1907282

>>1907281
sure the bacteria just spontaneously appear in the planet right?

>> No.1907283

>>1907272

How is that pwned? It doesn't change anything that was said earlier.

>Mitochondrial Eve is the most recent common matrilineal ancestor
No fucking shit, since we were talking about mtDNA

>> No.1907286

>>1907128

But seriously, the second answer is right. Lot of inbreeding and not a guarantee that the species will make it, but all you need is a male and a female.

There is no minimum or maximum number that a species will not go extinct. Any astronomical event, as in an asteroid striking the earth, could wipe out a species with a population in the billions (humans and all of the sundry species dependent on us).

>> No.1907297

>>1907283 pathetic attempt to derail the issue


>>1907214 He never used the word mitochondria

>>1907224 This guy then brought it up as a counter argument.

>>1907265 then he got destroyed and also showed how misinformed/retard he is.

QUESTIONS??

>> No.1907303

>>1907297
Are you a wizard?

>> No.1907304

>>1907286
dude shut up.. we are not talking about a single number for all species.. it obviosly depends on the species.. but every population has its own # or at least range around that value. that if it drops down.. the species will go extinct.

>> No.1907307
File: 22 KB, 400x417, 1285690621546.jpg [View same] [iqdb] [saucenao] [google]
1907307

>>1907303

>> No.1907312

>>1907304
yes,..
like European bison,...
its number is 12,...
seriously, is no one else amazed by that?

>> No.1907315

<span class="math"> N_e = (4N_m * N_f)/(N_m + N_f) [/spoiler]

calculating effective population size with skewed sex ratios.

>> No.1907318
File: 16 KB, 320x240, _0001_0004.jpg [View same] [iqdb] [saucenao] [google]
1907318

>>1907307
I... don't even know what this thread is about. So no.

>> No.1907333

>>1907286

Once again, bitches don't know about genetic diversity. Did you not read any of the posts in the thread?

MINIMUM VIABLE POPULATION: is a lower bound on the population of a species, such that it can survive in the wild.

PROTIP: It isn't 2.

>> No.1907358

<span class="math"> {1 \over N_e} = {1\over t}* \sum_{i=1}^t {1\over N_i} [/spoiler]

calculating effective popn size with bottleneck

>> No.1907368

>>1907333
Adam + Eve = 2 People.

Check and mate.

>> No.1907396 [DELETED] 

>>1907358

so say we have <span class="math">N_e[/spoiler] of 500 for 5 years and a 3 year bottleneck of 100 individuals, followed by a recovery of 500 individuals for 2 years.

<span class="math"> N_e = 1\over{({1 \over 500} + {1 \over 500} + {1 \over 500} +{1 \over 500} + {1 \over 500} + {1 \over 20} + {1 \over 100} + {1 \over 100} + {1 \over 500} + {1 \over 500})} * 10 [/spoiler]

<span class="math"> N_e = 227 [/spoiler]

So a population of 500 effective individuals suffering from a three year bottle neck of 100 individuals upon recovery only has an effective size of 227.

>> No.1907400

>>1907368

Stop calling them adam and eve. This thread is about the number of individuals needed to REpopulate a species

RE-populate.

>> No.1907406 [DELETED] 

>>1907358

So say a population is at 500 ind for 5 years, followed by a three year bottle neck of 100 ind, followed by recovery of 500 ind for two years.

N_e = [1\over({1 \over 500} + {1 \over 500} + {1 \over 500} +{1 \over 500} + {1 \over 500} + {1 \over 20} + {1 \over 100} + {1 \over 100} + {1 \over 500} + {1 \over 500})} * 10

<span class="math"> N_e = 227[/spoiler]

So an effective popn of 500 suffering from a three year bottleneck of 100 ind now has an effective popn of 227.

>> No.1907411

>>1907358

So say a population is at 500 ind for 5 years, followed by a three year bottle neck of 100 ind, followed by recovery of 500 ind for two years.

<span class="math">N_e = {1\over({1 \over 500} + {1 \over 500} + {1 \over 500} +{1 \over 500} + {1 \over 500} + {1 \over 20} + {1 \over 100} + {1 \over 100} + {1 \over 500} + {1 \over 500})} * 10[/spoiler]

<span class="math">N_e=227 [/spoiler]

So an effective popn of 500 suffering from a three year bottleneck of 100 ind now has an effective popn of 227.

>> No.1907413

These threads are /sci/ at its best.

>> No.1907422

>>1907411

disregard the <span class="math"> {1\over20}[/spoiler]. i meant it to be <span class="math"> {1\over100}[/spoiler] but forgot to change it from my previous example

>> No.1907449

>>1907358
>>1907315

Now a population with a skewed sex ratio undergoing a bottleneck is especially fucked.

Say <span class="math"> N = 200[/spoiler] but there are 40 females and 160 males.

<span class="math"> N_e = [4(160) * (50)/( 156 + 50)] [/spoiler]

<span class="math"> N_e = 128 [/spoiler]

Now this effective population will be bottlenecked to 20 individuals for five years, following recovery for two years.

<span class="math"> N_e = {1\over({1 \over 128} + {1 \over 20} + {1 \over 20} +{1 \over 20} + {1 \over 20} + {1 \over 20} + {1 \over 128} + {1 \over 128} + {1 \over 128})} * 7 [/spoiler]

<span class="math"> N_e = 37 [/spoiler]

So even though the population has 200 individuals, the sex ratio and bottleneck only allow 37 breeding individuals.

So in a population of 200 with a skewed sex ratio and bottleneck of 20 ind for five years, the breeding population is reduced to 37 ind, even though 200 individuals exist in the population.

Oh, and ITT: faggots who don't know population genetics.

>> No.1907455

>>1907411
dude what are you doing..

follow any cubic equation that has 0 and 2 positive values as roots -- the 1st the MVP lets say (a), and the 2nd the carrying capacity K-- and you have your fucking model.

<div class="math"> N= x(x-a)(x-k) </div>

there you go fag

>> No.1907460

>>1907455

Trolling fag is easily spotted.

>> No.1907463

>>1907460
shut up dumbass. you are not impressing anyone with your unrelated bullshit.. you just look like a fucking douche.

>> No.1907472

>>1907463

Troll harder. Those equations are for bottlenecks and even take into consideration non-equal sex survivorship.

Bottlenecks don't even take carry cap into consideration... because a bottlenecked popn is nowhere near K, you faggot troll.

Go to bed.

>> No.1907476

I remember reading once that for humans it was like 140-ish with two or three women to every man.

>> No.1907517

>>1907472
thats exactly the point..

WHO THE FUCK IS TALKING ABOUT population bottlenecks.. your are the faggot that brought that up

>> No.1907526
File: 58 KB, 750x600, 1251347286155.jpg [View same] [iqdb] [saucenao] [google]
1907526

>>1907517

1) *you're

2) read op's shit

>What's the word for the lowest number of individuals needed to repopulate a species?

>lowest number of individuals needed to repopulate a species

i.e. who tight can the bottleneck get without causing extinction.

Just go to bed, please.

>> No.1907554

ITT: Trolls Trolling Trolls Trolling Trolls

>> No.1907560

>>1907128
everyone knows you only need 2.

adam and eve were living proof of this
/MAJOR SARCASM
poe's law applies

>> No.1907575

>>1907526

pointing grammatical mistakes
>who tight

>i.e. who tight can the bottleneck get without causing extinction.

LOL? that's a fucking vague example, but you are 10% right 90% wrong.

Bottlenecks are just 1 biological cause to explain why populations go extinct when they drop a certain range.. Sure is related, but you are forgetting R-strategy, Mating Frequency, Predators, and Exogenous Variables.

the equation that i wrote down contemplate that you are aware of this factors.. so you can pic an adequate variable for "a"..

So please dont try to shove the fact that you took some intro level population genetics course.. and you feel all big shot and know-it-all when you dont.

If the question was about bottlenecks i would agree that is the right context for your statements.. but is not.

Stop being a retard.

>> No.1907613

>>1907575

>egregious grammatical error, point out typo

OP asked for "lowest number of individuals" be that by predators or a fucking earthquake, both cause a bottleneck.

Your math is bullshit, trying to boil down ecological factors to one variable, a.

And this is about bottlenecks as it is about "how low can you go and repopulate".

The answer isn't 2, for the trolls out there.

I wasn't even the first to invoke bottlenecks, fag.

>> No.1908771

>>1907201

not adam and steve