December 27, 2012

Zoogeographic map of the world

I have written informally about the Sahara-Arabia belt in conjunction with my "two deserts" theory of modern human origins (=pre-100kya in North Africa, post-70kya from Arabia), so it's nice to see that it corresponds to some real zoogeographic entity derived from the distribution of thousands of species. So, perhaps an early evolution of modern humans in that area, followed by their dispersal and admixture with other hominins living in the Palearctic and Afrotropical regions might make sense.

Science DOI: 10.1126/science.1228282

An Update of Wallace's Zoogeographic Regions of the World

Ben G. Holt et al.

Modern attempts to produce biogeographic maps focus on the distribution of species and are typically drawn without phylogenetic considerations. Here, we generate a global map of zoogeographic regions by combining data on the distributions and phylogenetic relationships of 21,037 species of amphibians, birds, and mammals. We identify 20 distinct zoogeographic regions, which are grouped into 11 larger realms. We document the lack of support for several regions previously defined based on distributional data and show that spatial turnover in the phylogenetic composition of vertebrate assemblages is higher in the Southern than in the Northern Hemisphere. We further show that the integration of phylogenetic information provides valuable insight on historical relationships among regions, permitting the identification of evolutionarily unique regions of the world.

Link

13 comments:

terryt said...

Interesting that SE Asia is part of the South Asian zone yet its people are almost universally considered East Asian. And we see quite a distinct zoogeographic boundary between SE and East Asia.

South Central Haplo said...

Not sure this applies to 2 legged animals. Other Flora and Fauna similarity is mostly known. What's new?.

shenandoah said...

Unlike South Central Haplo, I believe this actually ~could apply in some ways to the study of ~original Human species.

terryt said...

"Unlike South Central Haplo, I believe this actually ~could apply in some ways to the study of ~original Human species".

Of course it could, unless you're prepared to claim that humans are somehow completely different ot all other species on the planet. Obviously some exceptions would arise but that doesn't only apply to the human species. For example
New Zealand and australia form one zoogeographic region but the indigenous human populations in each region are different. But that applies to several other species as well. New Zealand has no marsupials other than those introduced by humans. And some of its biota have arrived during a period of island connections to the Southeast Asia/New Guinea region. But this connection was a mere interlude after the Gondwana connection and before the establishment of the prevailing westerly winds, which have carried many members of New Zealand's birds, insects and plants from Australia giving rise to the connection shown.

Similar exceptions could no doubt be found for many other regions.

Annie Mouse said...

I am noting the connection between Europe and Northern America.

It is my belief that this extended to large mammals (I cant recall the exact paper). So is likely to also allow for human movement (unlike the marsupial NZ example).

South Central Haplo said...

May be for Mammals and flora which evolved for millions of years . Monkeys spread around. But not convinced these zone classification was instrumental in hardly 100K human dispersal.

Fanty said...

It depends on how much humans stick to well known things and how much they want to try something completely different.

Fanty said...

Uh, missed an explanation for the above sentence.

Humans started as hunter/gatherers.
This map shows where a H/G encounteres similiar things to hunt and gather. However it displays the current state of it. Wuch must not mean it was all the time like this.

I can imagine, a lot of human tribes would have stuck to prey they knew instead of going to places with totaly different species of prey and exotic plants nobody knows if they are poisened or eatable.

Matt said...

This map shows where a H/G encounteres similiar things to hunt and gather.

Density and type may be more important than taxonomic position in all this.

If Region A has lots of large mammals, and a lot of humans who specialised into hunting them and borders 2 regions, Region B,of which has few large mammals, but they're the same large mammals, while Region C has a lot of large mammals, but they're a different species in the species taxonomy, then does B or C seem like a more attractive position for the hunter-gatherers of A?

The paper is gated, so I do not know the methodology, so is it based on density, or present/not present?

Fanty said...

At least I would say, that type of H/G that was involved in mesolithic Europe did occupy virtually exactly what is marked as one region: Europe+Sibiria. Through it seems they also inlcuded the Americas.

terryt said...

"I am noting the connection between Europe and Northern America. It is my belief that this extended to large mammals (I cant recall the exact paper)".

'Some' of that connection may go back 45 million years or so (I think it's about then). It seems not to have been till about then that the Atlantic Ocean finally became impassable for land animals. Other species in common between North America and Europe are possibly relic populations of species previoulsy spread through Siberia as well.

"Monkeys spread around. But not convinced these zone classification was instrumental in hardly 100K human dispersal".

Some years ago I read a book on Melanesian birds by Ernst Mayr and Jarred Diamond, and noticed that the spread of birds from SE Asia, through New Guinea, into Melanesia and then out to the Pacific exactly matched the pattern of human expansion through the same region. My conclusion was that wind had greatly assisted both, one through wing and the other through sail.

"However it displays the current state of it. Wuch must not mean it was all the time like this".

Not entirely true, as I understand the idea. I'm fairly sure the regions are based on fossil and extinct species as well. The 'barriers' between any two regions are therefore likely to be of long standing.

"I can imagine, a lot of human tribes would have stuck to prey they knew instead of going to places with totaly different species of prey and exotic plants nobody knows if they are poisened or eatable".

I think that is exactly right, and a factor not often given enough weight.

"If Region A has lots of large mammals, and a lot of humans who specialised into hunting them and borders 2 regions, Region B,of which has few large mammals, but they're the same large mammals, while Region C has a lot of large mammals, but they're a different species in the species taxonomy, then does B or C seem like a more attractive position for the hunter-gatherers of A?"

But the boundaries of the regions have not been influenced by any human action at all. The boundaries were in existence long before any human presence. They are 'zoogeographic' boundaries.

Matt said...

I'm not sure if this is relevant to what I have said. My only point is to illustrate:

Let's say we have regions A, B, C, D.

These are adjacent.

A and B have wolf species 1.
C and D have wolf species 2.
A and C have 20 wolves per square kilometre.
B and D have 50 wolves per square kilometre.

If you are a zoographer who is concerned with describing region with the same species, then the pairs A and B and C and D form clades of interest to you.

If you are person concerned with avoiding wolves (e.g. perhaps a hunter gatherer would be concerned with this) then the pairs A and C and B and D will be of interest to you, and will seem like a good zone to inhabit.

Obviously, most species will not cross zone borders, but these are not hard borders that every species is locked into observing but statistical aggregrate tendencies described by clustering. I would not bet too much on a species like Homo with strong tendencies towards large ranges and cosmopolitanism not violating these borders regularly and repeatedly.

Fanty said...

@Matt:

Its a matter of fact that humans crossed these borders. We can see that. Otherwise there wouldnt be humans in ALL these regions.

But I am sure that humans will prefer terretory similiar to what they are used to.

Thats even the case in modern times. Scandinavians and Germans prefered the northern most states, when they migrated to the USA.

Me personaly would also say, that tropical regions are a "No go" for me.

And so I guess, its the same for prehistoric humans. A H/G who is used to stags, wolfs, bears and Mammoth hunting, is possibly not going to like palm size Tarantulas, snakes and huge cats jumping on his neck from the trees.

I would kill the chief who wants us to go there and led my people back. ;-)