3 ms·

I wonder if there is something special about birds in the immediate post-Chicxulub period that makes the bird species hard to arrange in a tree. You might expec

I wonder if there is something special about birds in the immediate post-Chicxulub period that makes the bird species hard to arrange in a tree. You might expect that the few surviving birds were rapidly diversifying into ecological niches that were vacant after the asteroid. The sorts of genetic changes that make interbreeding impossible might lag behind (Eg changes in numbers of chromosomes) since the frequency of such species-bifurcating events would be based on other mechanisms not related to available ecological niches. So perhaps there's a period in which birds that look completely different can still interbreed to a larger extent than now? It would be like ring species, but taken to an absurd degree. I'm kinda riffing without really knowing what I'm talking about, but imagine a world where birds of all shapes and sizes can interbreed and occasionally do so.

7952 4y ago
Maybe certain genes facilitate a particular strategy to evolution. And part of an organisms phenotype makes the species evolve in a particular way that gives genes an advantage over successive species. Adapting to the evolutionary environment. And naively birds are different. They can fly great distances in a single lifetime and cross many different habitats. In the time dimension that is very different to a plant or a small mammal. Not sure if that actually makes a difference though over such long timescale. An insect family can spread across the world just like a bird can.
cwmma 4y ago
Sounds like "push of the past" [1] basically successful species often stem from a highly successful adaption so show intense diversification early on, like birds when they are suddenly the only flying species. 1. https://en.wikipedia.org/wiki/Push_of_the_past?wprov=sfla1 https://en.wikipedia.org/wiki/Push_of_the_past?wprov=sfla1
Tao3300 4y ago
I have a feeling it's the simple fact that most bird species can fly and many of those species migrate incredible distances. This means (1) bird populations spread out and (2) they face survival pressure across multiple ecosystems. Caveat emptor, that's just my layperson's "makes sense to me" hunch. No credentials or citations.

7952 4y ago

Maybe certain genes facilitate a particular strategy to evolution. And part of an organisms phenotype makes the species evolve in a particular way that gives genes an advantage over successive species. Adapting to the evolutionary environment. And naively birds are different. They can fly great distances in a single lifetime and cross many different habitats. In the time dimension that is very different to a plant or a small mammal. Not sure if that actually makes a difference though over such long timescale. An insect family can spread across the world just like a bird can.

cwmma 4y ago

Sounds like "push of the past" [1] basically successful species often stem from a highly successful adaption so show intense diversification early on, like birds when they are suddenly the only flying species. 1. https://en.wikipedia.org/wiki/Push_of_the_past?wprov=sfla1 https://en.wikipedia.org/wiki/Push_of_the_past?wprov=sfla1

Tao3300 4y ago

I have a feeling it's the simple fact that most bird species can fly and many of those species migrate incredible distances. This means (1) bird populations spread out and (2) they face survival pressure across multiple ecosystems. Caveat emptor, that's just my layperson's "makes sense to me" hunch. No credentials or citations.