STREAMING NOW: Watch Now

Inbreeding may have helped cause Neanderthals to go extinct, study says

Neanderthals went extinct around 40,000 years ago -- about the same time that modern humans migrated out of Africa. This has led researchers to believe that...

Posted: Nov 27, 2019 11:32 AM
Updated: Nov 27, 2019 1:45 PM

Neanderthals went extinct around 40,000 years ago -- about the same time that modern humans migrated out of Africa. This has led researchers to believe that modern humans won the competition for resources, leading to the demise of Neanderthals.

Other theories around the environmental pressure of climate change or even epidemics maintain those reasons could have helped Neanderthals to go extinct.

But a new study proposes that modern humans had nothing to do with it. Instead, the researchers suggest that inbreeding, small populations and fluctuations in birth, death and sex ratio would have been enough to lead the Neanderthals to their permanent end. The study published Wednesday in the journal PLOS.

Previous research suggested that Neanderthals had small populations before modern humans made their appearance. Neanderthals were also spread out in isolated, local areas.

The researchers for this study created population models, based on data from hunter-gatherer groups, with a range of population sizes as small as 50 to a maximum of 5,000.

They simulated the population change in response to changes in birth and death rates, inbreeding and a factor known as Allee effects. Allee effects are when small population size has a negative impact on the reproductive fitness of individuals.

Inbreeding, a practice of mating between relatives, was common among Neanderthals according to previous research. Inbreeding also leads to a reduction of reproductive fitness.

Neanderthals had 40% lower reproductive fitness than modern humans, according to previous research cited in the new study.

The simulations took place on a 10,000-year timescale. The researchers found that it was unlikely that inbreeding could be solely responsible for extinction because it only occurred in the model with the smallest population.

But Allee effects, like 25% or less females giving birth in one year, could have caused extinction in populations with 1,000 Neanderthals. Combined with inbreeding and fluctuations in birth and death rates, extinction would have been likely on their timescale over 10,000 years.

The researchers allowed that if modern humans had any effect on Neanderthal extinction, it's possible that the Neanderthal populations may have shifted -- which could lead to inbreeding, a low birth rate and other factors accounted for in the study.

'Did Neanderthals disappear because of us? No, this study suggests,' the authors wrote. 'The species' demise might have been due merely to a stroke of bad, demographic luck.'

Oregon Coronavirus Cases

Data is updated nightly.

Confirmed Cases: 9636

Reported Deaths: 209
CountyConfirmedDeaths
Multnomah236169
Marion159547
Washington149120
Clackamas79524
Umatilla6674
Union3551
Lincoln3452
Deschutes2010
Lane1963
Malheur1601
Linn1569
Polk15412
Jackson1400
Yamhill1328
Jefferson1310
Klamath1251
Benton915
Hood River880
Wasco851
Morrow821
Clatsop490
Douglas450
Josephine441
Coos420
Columbia350
Lake200
Tillamook130
Crook120
Wallowa100
Curry80
Baker40
Sherman20
Grant10
Harney10
Gilliam00
Unassigned00
Wheeler00

California Coronavirus Cases

Data is updated nightly.

Confirmed Cases: 250514

Reported Deaths: 6315
CountyConfirmedDeaths
Los Angeles1078063457
Riverside19450479
Orange15778360
San Diego15696387
San Bernardino13676269
Imperial6979105
Alameda6472140
Fresno562677
Kern510080
Santa Clara4849160
Tulare4627136
San Joaquin447455
San Francisco377650
Sacramento355969
San Mateo3441108
Contra Costa343279
Santa Barbara326129
Ventura324047
Marin271019
Kings258332
Stanislaus239144
Monterey179115
Solano147625
Merced127211
Sonoma126710
Placer78611
San Luis Obispo7012
Yolo58324
Madera5665
Santa Cruz4173
Napa3444
San Benito2572
Lassen2340
Butte2063
El Dorado2060
Sutter2063
Humboldt1444
Shasta1354
Nevada1231
Glenn1220
Yuba1031
Tehama881
Lake850
Mendocino850
Colusa700
Calaveras530
Del Norte511
Tuolumne430
Mono411
Inyo331
Siskiyou310
Mariposa271
Amador260
Plumas110
Alpine20
Trinity20
Sierra10
Unassigned00
Medford
Clear
55° wxIcon
Hi: 86° Lo: 53°
Feels Like: 55°
Brookings
Clear
49° wxIcon
Hi: 64° Lo: 47°
Feels Like: 49°
Crater Lake
Clear
43° wxIcon
Hi: 75° Lo: 44°
Feels Like: 43°
Grants Pass
Clear
52° wxIcon
Hi: 85° Lo: 52°
Feels Like: 52°
Klamath Falls
Clear
43° wxIcon
Hi: 80° Lo: 42°
Feels Like: 43°
Beautiful 4th of July Weekend
KDRV Radar
KDRV Fire Danger
KDRV Weather Cam

Community Events