Marmosets are primates that typically give birth to twins. (Image credit: Tambako The Jaguar/flickr, CC BY-ND)
Posted on 01/06/2025 11:28:11 AM PST by BenLurkin
The number of offspring a species has in a litter is phylogenetically conserved, meaning more similar in more closely related species. Deer tend to have one or two offspring, while canids and felids tend to have many more babies in each litter.
Almost all primate species give birth to just one baby, although there are exceptions. Several of the wet-nosed primates — including lemurs, lorises and galagos — and almost all of the marmosets and tamarins from South America give birth to twins.
Marmosets are primates that typically give birth to twins.
(Image credit: Tambako The Jaguar/flickr, CC BY-ND)
Prior to our work, researchers thought these distinctive twin-bearing primates must be what evolutionary biologists call derived, or different, from the more common, ancestral trait. But our research flips that narrative on its head: It's actually the singleton-bearing primates that are derived and distinctive. Further back in evolution, two babies at once was the norm. Our ancient primate ancestors gave birth to twins.
So, when did this evolutionary change in primate litter size occur?
Family tree of mammals surveyed for the study, also known as a phylogeny. The branches of the tree are labeled with colors that correspond to litter size. Darker colors indicate larger litter sizes, while lighter colors (oranges) indicate smaller litter sizes. The animal outlines are, from top to bottom, rodents, rabbits, primates, cetartiodactyls (whales and most hooved animals), carnivores, bats and shrews. (Image credit: Image modified from McBride and Monson, 2024)
(Excerpt) Read more at livescience.com ...
Moral of the story: Big animals have smaller litters?
How nice.
But what about those of us who don’t have “ancient primate ancestors”?
What is the primate that is between the silhouettes of the bear and the shrew?
Darwinist: You've got that backwards.
Democrats: This is how we know eugenics is the way to go.
Me: If natural selection works, then why do you have to play God on who makes babies and who doesn't?
“ontogeny recapitulates phylogeny”?...................
Good news. Have all the twins you want!
Enhances the transformamogration of exious fentalbenomes.
What is the primate that is between the silhouettes of the bear and the shrew?
-
An ancient space alien. They died out long ago. The left us with mysterious megalithic stone structures that modern humans cannot build. Ancient Alien theorists say, “Yes”.
Looks like a bat
‘ But what about those of us who don’t have “ancient primate ancestors”?’
You a lizard?
I hate it when that happens.................
Nope.
Just someone who hasn’t rejected God for some fanciful human train of thought.
The science is in tension.
Very interesting.
Women who are in their 30s are more likely to have twins
Women who take fertility drugs are more likely to have twins
Twin rates are about 3%
Many twins are premature and have to spend time in neonatal care.
Bat.
If only I had a nickel for every time I have said this very thing to my husband...
Bears have bumps in litter count after population declines from weather etc too
Yeah... Sure...
Also, the 2020 election was squeaky clean and honest...
I had a first cousin once removed who was a twin--her twin sister died at birth but she lived to 96. Their mother was 30 when they were born.
My grandmother and her brother were twins--their mother was 26 when they were born. I have a second cousin who had twins when she was 26. One of them is the father of twins who were born when their mother was 30. My other grandmother had younger sisters who were twins, born when their mother was 34.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.