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by porb121 1740 days ago
this comments are like bingo for climate science misunderstanding

evolution doesn't happen on time scales of 100 years

+1.1 avg temperature implies much larger localized changes

5 comments

Agreed. Yes, some animals will handle it, and we'll hold them up as examples. But the crash in diversity from all those who don't is tragic. The genetic diversity that is the bounty of millions of years of iteration and "learning" in ecological systems is a huge loss to our planet's resources and (by proxy) our own future wealth.
> evolution doesn't happen on time scales of 100 years

Phenotypic selection does happen on this timescale. Industrial melanism[1] has been pretty well studied.

[1] https://en.wikipedia.org/wiki/Industrial_melanism

Yeah – and on top of that, the commenting user seems to underestimate the gravity of "only" a few degrees:

> The study also calculates extinction risks at different warming levels. It finds that 2% of endemic species are at risk of extinction if warming is limited to 1.5C, and 4% are at risk at 2C. However, the risk rises to 20% for land-based ecosystems, and to 32% in marine ecosystems if warming hits 3C.

https://www.weforum.org/agenda/2021/04/climate-change-will-h...

Evolution happens on the time scale of "birth" to reproductive age for the organism in question. I know of no corporeal entity still considered adolescent after a century.

I have never even worked with an evolutionary biologist but the concept of "punctuated equilibrium" has been around for quite a while.

[] my sloppy use of "birth" includes cells budding, seeds sprouting and the rest of the messy details.

[] https://en.wikipedia.org/wiki/Punctuated_equilibrium

Extremely out of my league here, but it seems logical to me that if there is a mutation, it only initially happens in a single organism. Like a single specific bear might mutate, but certainly not all of them at the same time. That organism then needs to mature (if not already) and reproduce to spread the new mutation. It seems it would take several generations of successful breeding and on top of that successful passing on of the mutated gene to have the mutation actually spread beyond just the initial one. Reproduction rate of the organism would also play a huge factor I'd imagine, like a mouse can have hundreds of offspring in a single year due to a 21 day gestation period compared to a human.
> evolution doesn't happen on time scales of 100 years

Evolution may not, but selection may happen on that time scale, especially for animals that live short lives.

What is the difference between selection and evolution?
Selection is a process by which evolution works, so this is a false distinction. Modern definitions of evolution are usually something along the lines of changes in a population over time. There's no inherent time scale over which those changes can be observed, except for that of the generation time itself.