Sean B. Carroll

And I mean, the annual deer hunt is a huge thing culturally and the deer herd is enormous, but some of the pioneering ecologists of the 20th century understood that that was a huge change from say that from the 19th century and that deer exploded when you took away their predators.

so predators have a big role in controlling the size of populations of their prey and take away the top predators and you can have an explosion in the number of their prey so really deer numbers are abnormal all over the country because they have no essentially no significant natural predators i mean there are a few you know wolves are coming back in various places but they're not making a dent

so predators have a big role in controlling the size of populations of their prey and take away the top predators and you can have an explosion in the number of their prey so really deer numbers are abnormal all over the country because they have no essentially no significant natural predators i mean there are a few you know wolves are coming back in various places but they're not making a dent

so predators have a big role in controlling the size of populations of their prey and take away the top predators and you can have an explosion in the number of their prey so really deer numbers are abnormal all over the country because they have no essentially no significant natural predators i mean there are a few you know wolves are coming back in various places but they're not making a dent

now deer have spread over all these you know suburban and urban populations and they're making a living on our gardens right so um yeah so so deer you can i know they're cute uh but they are essentially an invasive species um or at least they're a species that's out of control um out of natural control so you know i think deer are with us to stay in these large numbers but

now deer have spread over all these you know suburban and urban populations and they're making a living on our gardens right so um yeah so so deer you can i know they're cute uh but they are essentially an invasive species um or at least they're a species that's out of control um out of natural control so you know i think deer are with us to stay in these large numbers but

now deer have spread over all these you know suburban and urban populations and they're making a living on our gardens right so um yeah so so deer you can i know they're cute uh but they are essentially an invasive species um or at least they're a species that's out of control um out of natural control so you know i think deer are with us to stay in these large numbers but

That's a great point, Mike. In fact, essentially the third rule. And that third rule is that the density of populations is sort of self-limiting. So when there's a lot of food, abundant food and populations are small, they will grow explosively.

That's a great point, Mike. In fact, essentially the third rule. And that third rule is that the density of populations is sort of self-limiting. So when there's a lot of food, abundant food and populations are small, they will grow explosively.

That's a great point, Mike. In fact, essentially the third rule. And that third rule is that the density of populations is sort of self-limiting. So when there's a lot of food, abundant food and populations are small, they will grow explosively.

But as that sort of population fills up the space and as food starts to become limiting, that will slow or in fact sort of reverse that to a population decline. So lots of things are density regulated. And so deer are, you know, have expanded their habitat. They're filling, you know, our suburban areas and things like that. But there's still limits on deer in terms of food abundance.

But as that sort of population fills up the space and as food starts to become limiting, that will slow or in fact sort of reverse that to a population decline. So lots of things are density regulated. And so deer are, you know, have expanded their habitat. They're filling, you know, our suburban areas and things like that. But there's still limits on deer in terms of food abundance.

But as that sort of population fills up the space and as food starts to become limiting, that will slow or in fact sort of reverse that to a population decline. So lots of things are density regulated. And so deer are, you know, have expanded their habitat. They're filling, you know, our suburban areas and things like that. But there's still limits on deer in terms of food abundance.

And there's also, you know... there's cars you know as you know there's lots of collisions and things like this so there's various things that are um constraining the deer population as well as disease, you know, because they have certainly acquired some diseases now that they're in close contact with humans.

And there's also, you know... there's cars you know as you know there's lots of collisions and things like this so there's various things that are um constraining the deer population as well as disease, you know, because they have certainly acquired some diseases now that they're in close contact with humans.

And there's also, you know... there's cars you know as you know there's lots of collisions and things like this so there's various things that are um constraining the deer population as well as disease, you know, because they have certainly acquired some diseases now that they're in close contact with humans.

So, yeah, so this, the general concept is that in no area will be, there is a limit to how much can be carried by, the population can be carried in any given area, you know, limited particularly by food supply.

So, yeah, so this, the general concept is that in no area will be, there is a limit to how much can be carried by, the population can be carried in any given area, you know, limited particularly by food supply.

So, yeah, so this, the general concept is that in no area will be, there is a limit to how much can be carried by, the population can be carried in any given area, you know, limited particularly by food supply.

That's a hugely important, maybe sort of philosophical question. I think, you know, you said earlier about how nature kind of works these things out. Let's take something like a beaver and you could say, all right, a beaver builds a dam and that dam diverts some water. And, you know, does that impact other creatures? It certainly does.