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Related: Editorials & Other Articles, Issue Forums, Alliance Forums, Region ForumsBill Nye explains the science behind skin color: 'We're all one species': The New York Post
"It turns out everybody on Earth is descended from people that live here, Africa, he says while pointing to a map. As groups of us moved around the world, the color of our skin had to change, and heres why.
snip
Skin is where we make Vitamin D. If you dont get enough ultraviolet, you dont get enough vitamin D, the bow-tie wearing scientist, 64, says. If you have too much ultraviolet, you break down your folates. You have to have it in perfect balance, he explains, showing a meter ranging from pale beige to dark brown.
Because the ultraviolet varies, the color of our skin varies, and thats it!
He ended the video with an important reminder: Were all one species! But were not treating each other fairly. Not everybody is getting an even shake, he says. Its time to change things.
link: https://nypost.com/2020/07/23/bill-nye-on-the-science-of-skin-color-were-all-one-species/
Here I've been thinking of writing an op on this very topic. But Bill Nye beat me to it and did it better!
Laelth
(32,017 posts)Nyes explanation of differences in skin color is also spot on, but its our ability to interbreed that defines us as a single species.
-Laelth
Loki Liesmith
(4,602 posts)Humans could interbreed with Neanderthals and Denisovans.
Polar bears and grizzlies also mate and produce viable offspring.
Skraxx
(2,964 posts)breeding.
Loki Liesmith
(4,602 posts)An occipital knot of bone at the rear of your skull those features are quite plausibly neanderthal in origin. There is still some debate and red hair and freckles I think.
Laelth
(32,017 posts)I was of the belief that the ability to interbreed (and create fertile offspring, unlike the infertile offspring of a horse and a donkey, i.e. a mule) was the principal defining characteristic of a unique species.
Please enlighten me. Upon what bases are species now defined and delineated?
-Laelth
PTWB
(4,131 posts)
Species
1. a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. The species is the principal natural taxonomic unit, ranking below a genus and denoted by a Latin binomial, e.g. Homo sapiens.
While there are exceptions (see ligers) to this definition, it doesnt change the fact that it is the definition in the first place.
Loki Liesmith
(4,602 posts)There are many more exceptions to the rule within every branch of the evolutionary tree. The inability to interbreed is a function of genetic distance which is a continuous variable. As such anywhere you try and impose the above definition you are going to create points of failure.
For example a grizzly bear population has significant polar bear genetic inflow. There are few pure grizzlies. Are they still grizzly bears? Or are they very diluted polar bears? Both? What does species even mean in this context?
Its better to acknowledge that species is not a real thing. Its a convention and is only ever approximately real.
PTWB
(4,131 posts)42bambi
(1,753 posts)and we're all of one political affiliation; Equally human, all living in one world. That's a far away dream, but one can hope.
Yeehah
(4,523 posts)He is having an impact and helping to make the world a better place.
2naSalit
(86,040 posts)Shit, it's a tenet of anthropology for krissakes. It used to be one of the first lessons in ANTHR101.
Race is a social construction just like religion and rules of any kind.
To Bill Nye!
malaise
(267,799 posts)Back in the day when science rules, he was invited to the White House by that black guy
Loki Liesmith
(4,602 posts)We all are predominantly Homo sapiens.
Europeans tend to have small but detectable presence of Homo neanderthalensis, while East Asians have Homo sapiens, Homo neanderthalensis and Homo denisova admixtures. But the core stock of all of us is sapiens.