New human-like species discovered • Hacker News Board

Re: New human-like species discovered

#121

Post by ceejayoz » Thu, Sep 10, 2015, 3:39 PM UTC

mklim wrote: post #77

ceejayoz wrote: post #73

Earlier quoted context omitted.

> I do seem to remember being taught in school that the definition of species is "organisms that can reproduce and generate fertile offspring". Which is problematic for extinct animals. We have no way of knowing if modern humans would be able to produce offspring with Neanderthals, for example.

The current body of evidence suggests that we could and did, since Neanderthal DNA is present in some modern humans [1]. [1] http://www.bbc.com/news/science-environment-33226416

That suggests we did. It doesn't necessarily suggest we still could. Nicely illustrates why speciation is more complex than "can't interbreed" though.

Re: New human-like species discovered

#122

Post by wpankey » Thu, Sep 10, 2015, 3:40 PM UTC

RogtamBar wrote: post #83

thaumasiotes wrote: post #41

Earlier quoted context omitted.

What's stopping a future anthropologist from declaring siberians and pygmies to be different species? It's not done now for political reasons, but the future has no reason to be concerned with the past's special sensitivities. Consider that "spanish" and "italian" are officially separate languages, while the US and Scotland both officially speak "english". The terminology won't help you predict which pair has an easi…

It's a political thing. Species definition is messy, to the point of absurdity. Indeed, the differences between long-separated human populations are such that even non-racist scientists acknowledge subspecies.. http://dienekes.blogspot.sk/2009/09/is-homo-sapiens-polytypi...

Thanks for posting this. It has always baffled me that we are led to believe that all of humanity springs from one common root. Absolutely ridiculous and goes against common sense -what other species (of anything) has just one single representative??? Who's been selling this and why???

Re: New human-like species discovered

#123

Post by JoeAltmaier » Thu, Sep 10, 2015, 3:44 PM UTC

ceejayoz wrote: post #84

lighthawk wrote: post #81

Earlier quoted context omitted.

521 not 512, according to the article you mention.

Typing too fast, thanks! The difference probably won't help bridge the millions of years gap though. :-)

Yet we have Neanderthal dna? Oh, right, that's only 40,000 years. Not 1-3 million.

Re: New human-like species discovered

#124

Post by crimsonalucard » Thu, Sep 10, 2015, 3:52 PM UTC

Bad headline. They found fossils. No actual living thing discovered.

Re: New human-like species discovered

#125

Post by Ologn » Thu, Sep 10, 2015, 3:55 PM UTC

eru wrote: post #82

kissickas wrote: post #70

Earlier quoted context omitted.

A species cannot be clearly defined until you try to mate it with something else and it fails to produce a viable offspring, as far as I'm aware. No DNA analysis is indisputable with what we currently know.

So each infertile individual belongs into their own species?

One method of speciation is reproductive isolation. One model for this is the Bateson–Dobzhansky–Muller model, where if a species is, say, separated by distance, and then subgroup A has a change at one loci, and subgroup B has a change at another loci, and due to these mutations, individuals from subgroup A can no longer reproduce with individuals fom subgroup B - then it can be said that speciation from reproductive isolation has occurred according to this model.

Re: New human-like species discovered

#126

Post by bpicolo » Thu, Sep 10, 2015, 4:02 PM UTC

Lawtonfogle wrote: post #80

njharman wrote: post #26

Something I've never understood (since highschool some 30 years ago) is; when getting partial skeletons perhaps from only a single individual, how can they claim new species? I mean what's diff with that and some hypothetical future anthropoligist looking at siberian with roundish skull thicker brow ridges and that of six foot tall masai with long face and then a sub 5 foot native peruvian and declaring them all diff…

If species were based on bone structure, how many species of dogs would there be?

I still think it's super weird that they don't count as different species.

There's the suggestion that breeding + fertile offspring is the main concern, but couldn't early humans and neanderthals reproduce, for example? But we definitely consider them separate species.

Dividing lines are hard here I guess.

Re: New human-like species discovered

#127

Post by bjelkeman-again » Thu, Sep 10, 2015, 4:03 PM UTC

JoeAltmaier wrote: post #123

ceejayoz wrote: post #84

Earlier quoted context omitted.

Typing too fast, thanks! The difference probably won't help bridge the millions of years gap though. :-)

Yet we have Neanderthal dna? Oh, right, that's only 40,000 years. Not 1-3 million.

Yes. The Neanderthal species supposedly died out about 40k years ago. [1] In this article they talk about a species that may be millions of years older.

[1] https://en.m.wikipedia.org/wiki/Neanderthal

Re: New human-like species discovered

#128

Post by jessriedel » Thu, Sep 10, 2015, 4:04 PM UTC

JoeAltmaier wrote: post #123

ceejayoz wrote: post #84

Earlier quoted context omitted.

Typing too fast, thanks! The difference probably won't help bridge the millions of years gap though. :-)

Yet we have Neanderthal dna? Oh, right, that's only 40,000 years. Not 1-3 million.

Yea, I wonder how that's reconciled. The Neanderthal DNA comes from a 38k year-old specimen:

> The researchers recovered ancient DNA of Neanderthals by extracting the DNA from the femur bones of three 38,000-year-old female Neanderthal specimens from Vindija Cave, Croatia, and other bones found in Spain, Russia, and Germany.[8] Only about half a gram of the bone samples (or 21 samples each 50–100 mg[1]) was required for the sequencing, but the project faced many difficulties, including the contamination of the samples by the bacteria that had colonized the Neanderthal's body and humans who handled the bones at the excavation site and at the laboratory.

https://en.wikipedia.org/wiki/Neanderthal_genome_project

2^(38000/521)=10^22, so there must be other effects. That Nature article says

> The team predicts that even in a bone at an ideal preservation temperature of −5 ºC, effectively every bond would be destroyed after a maximum of 6.8 million years. The DNA would cease to be readable much earlier — perhaps after roughly 1.5 million years, when the remaining strands would be too short to give meaningful information.

which I don't know how to square with the 521 year figure. I think maybe 521 years is at the high temp?

Re: New human-like species discovered

#129

Post by [deleted] » Thu, Sep 10, 2015, 4:06 PM UTC

kissickas wrote: post #70

JoeAltmaier wrote: post #63

Earlier quoted context omitted.

Do we still depend on bone structure to define species? DNA analysis is indisputable. Its all speculation until that is done.

A species cannot be clearly defined until you try to mate it with something else and it fails to produce a viable offspring, as far as I'm aware. No DNA analysis is indisputable with what we currently know.

[deleted]

Re: New human-like species discovered

#130

Post by iso8859-1 » Thu, Sep 10, 2015, 4:08 PM UTC

sricciardi wrote: post #68

thaumasiotes wrote: post #41

Earlier quoted context omitted.

What's stopping a future anthropologist from declaring siberians and pygmies to be different species? It's not done now for political reasons, but the future has no reason to be concerned with the past's special sensitivities. Consider that "spanish" and "italian" are officially separate languages, while the US and Scotland both officially speak "english". The terminology won't help you predict which pair has an easi…

Spanish and Italian are MUCH more different than American English and Scottish(?) English.

He was probably thinking of Scots: A 2010 Scottish Government study of "public attitudes towards the Scots language" found that 64% of respondents (around 1,000 individuals being a representative sample of Scotland's adult population) "don't really think of Scots as a language" (Wikipedia)