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Right, but I bet very few new species have emerged in the last few hundred years because of habitat fragmentation. More likely we caused the population of many

Right, but I bet very few new species have emerged in the last few hundred years because of habitat fragmentation. More likely we caused the population of many animals to decrease or extirpated them entirely (if not drove them to extinction).

stephencanon 7y ago
The coywolf isn't a species (and wolves and coyotes only "diverged" ~100k years ago anyway, IIRC), but they surely became much more common in the exurban northern US after the 1960s. More generally, I believe that there's been an increase in many mid-size mammals in the northeast US as habitats became too small for the large carnivores. So it's not just extirpation and decreasing numbers, but it's also not good.
Swizec 7y ago
Would we even call them new species within a few hubdred years or would they be seen as “just variations”? Many species are absolutely thriving under human invasion and forming new behavioral and breeding patterns that in some cases are even leading to physical changes. Many burds like crows and sparrows love human environments. Trash pandas love us too. Hawks love cities almost as much as mountains. So many tall places to survey from. There’s also fish who have started being smaller in adult size due to sports fishing and size regulation. Stuff like that. Oh and crowd are known to have branched into novel food sources because they can use cars to break hard nuts they otherwise couldn’t open. It’s not all doom and gloom. Nature is hella robust.
- gerbilly 7y ago
  This is a well written article on the topic. It argues that human pressures may be selecting out only the hardiest most adaptable species such as rats, mice, pigeons, sparrows, etc... If this goes on unabated, we'll be left with an ecosystem with much lower diversity. http://www.davidquammen.com/sampler/18-planetofweeds http://www.davidquammen.com/sampler/18-planetofweeds

stephencanon 7y ago

The coywolf isn't a species (and wolves and coyotes only "diverged" ~100k years ago anyway, IIRC), but they surely became much more common in the exurban northern US after the 1960s. More generally, I believe that there's been an increase in many mid-size mammals in the northeast US as habitats became too small for the large carnivores. So it's not just extirpation and decreasing numbers, but it's also not good.

Swizec 7y ago

Would we even call them new species within a few hubdred years or would they be seen as “just variations”? Many species are absolutely thriving under human invasion and forming new behavioral and breeding patterns that in some cases are even leading to physical changes. Many burds like crows and sparrows love human environments. Trash pandas love us too. Hawks love cities almost as much as mountains. So many tall places to survey from. There’s also fish who have started being smaller in adult size due to sports fishing and size regulation. Stuff like that. Oh and crowd are known to have branched into novel food sources because they can use cars to break hard nuts they otherwise couldn’t open. It’s not all doom and gloom. Nature is hella robust.

gerbilly 7y ago
This is a well written article on the topic. It argues that human pressures may be selecting out only the hardiest most adaptable species such as rats, mice, pigeons, sparrows, etc... If this goes on unabated, we'll be left with an ecosystem with much lower diversity. http://www.davidquammen.com/sampler/18-planetofweeds http://www.davidquammen.com/sampler/18-planetofweeds