One of my favorite Sean Carrolls

I normally don't watch Biology stuff but watched this anyway due to UKposts's suggestion playlist. I think their algorithm knows more about me than myself. Really enjoyed this lecture and learnt something new today. Thanks to the Ri.

The Serengeti Rules (Rules of regulation / How life works / to intervene in ecosystems) 1). Keystone Species: Some animals are more equal than others. Keystone species regulate community diversity. 2). Trophic Cascades: Some species have strong indirect effects on others through trophic cascades. 3). Density: The regulation of some species depends upon their density (ie. numbers and distribution). 4). Nature is resilient: Given a chance (habitat, protection, time), populations can rebound dramatically. In general... * Identify the key players (/species, factors, molecules) that regulate a process. * Identify the rules that govern the interactions. * Replace what is missing or fix broken links. A very informative and interesting talk on evolutionary biology by Sean B. Carroll :)

This video was my first encounter with Dr. Carroll, watching a few years ago. Just re-watching with my wife. He became one of my favorite writers as well. For example: Brave Genius, Remarkable Creatures, Endless Forms Most Beautiful. I read these books, and yinz all should too!

This lecture carries an extremely positive message, that if we make the right corrections, damage to nature can be readily fixed. I was very impressed by the style and content of this lecture, and by no means did I think it was unnecessarily padded as some commenters below suggest.

this seems to be one of the Ri Christmas lectures, which are primarily for kids. I particularly like the way he doesn't at all talk 'down' to his audience. Great talk.

What a wonderful presentation - there is hope after all! Thanks for uploading!

Thanks for the fascinating lecture!

THIS MAN IS A GREAT TEACHER, SCIENTIST AND EDUCATOR! Look at the way he receives the answers of the kids!

Dr. Carroll is an excellent speaker, with an interesting, thoughtful, and optimistic message. Well worth an hour of time!

One of the most interesting and engaging lectures in the series, imho.

Thanks for sharing this story of the resilience of nature.

Wow, Sean Caroll has his alter ego - by day he is an evolutionary biologists; By night, a Cosmologist and physicist... And in order not to confuse himself he changes his middle name... and a beard.

Top notch lecture. Thank you RI.

Fascinating lecture, now Gorongosa park on my list to see places.

Wonderful presentation. I am not a biologist, but was completely informed and inspired by this talk.

His words explained the difficulty terms of science in easier to understand. It 's a great way and in more interesting 👏🏻👏🏻👏🏻.

Mr. Carroll - Karibu Tanzania!

Excellent presentation from a dedicated person. Well done Sir.

In the Teton and Yellowstone Park not only do the wolves reduce the numbers of browsers but the animals avoid the cover of the aspen and other small trees because the the wolves use the cover to ambush them. The browsers concentrate down in the open prairie of Jackson Hole and Yellowstone valley. The mountain pika are getting a a little extra chance to survive as well because foxes and coyotes, their major predictor, is being driven out by the wolves. It shows that wolves have been a boon for the area in more ways than imagined.

I came for the physicist, stayed for the biologist.

Excellent presentation I really enjoy listening to an intelligent and articulate man such as this Bravo Sir

Thank you. this was an awesome lecture. Really eye opening.

Thank you. This talk was wonderful

Amazing lecture and absolutely worth an hour of your life.

Wow.. what a thoughtful genius man. He made the whole restoration and preservation concept of wilds so easy to understand for us all. 😊 Wonderful presentation sir..

Excellent talk by Sean Carroll!

Very enjoyable and informative presentation. Thank you Sean Carroll and RI.

I am currently studying this in 3rd year to understand how we can build integrated multitrophic agri/aquacultural systems (IMAS) to sustainably feed the planet without destroying the keystones of the planet's ecosphere. This talk has also helped me understand my post-graduate goals. If you notice, it was feeding humans that started the degradation of the Serengeti in the first place (the virus from domesticated bovines). The solution is to decouple our food production from the environment, until the food production environment is itself a more bio-diverse ecosphere than it's environment. A simple example might be bird habitat and provision of water. A complex example might be the evolution of various preferential microbial, fungi and plant species migrating into the local environment and attracting wildlife. With properly built food production systems built upon the principals of 'trophic cascade', our inputs into this system need merely be sequestered carbon, pure organic ammonia, and some minerals. Sunlight, autotrophs and atmospheric oxygen does the rest. The output can be whatever you want - fish, crustaceans, molluscs, algal products, most plants - even energy generation. But yeah - you have to hear the idea first, believe in it - and then fund it.

A fascinating presentation, and it should be really heartening to learn how nature can bounce back... with some help. But I fear that this useful and informative lecture paints on a canvas which ignores the bigger picture of trends and likely future developments, and also glosses over (or does not mention) the fact that there are areas where the virtual eradication of key species, and in some cases nearly all species, gives the appearance of being irrevocable (marine environments such as the Newfoundland Grand Banks for example). I am very pleased that the Serengeti and the Gorongosa National Parks have seen a renaissance of wildlife and bio-diversity. But a reliance on tourist income and on governmental protection means dependance on two things: namely a thriving international leisure and tourist industry and an effective government, and neither of these are likely to survive in the face of developing and accelerating trends. The depressing facts are that in many areas (Africa and Asia especially, but also elsewhere) the combination of unsustainable population growth and shrinking food resources, due in large part to the effects of Climate Change, will likely bring about the collapse of effective government, rising civil unrest and conflict, mass migration of populations, the disappearance of tourism, and the physical degradation of many environments due to changes in weather patterns (often drought, but perhaps including catastrophic flooding in some places, eg. Bangladesh). The twenty year war in Mozambique (not really a civil war as the MNR, or 'Renamo' in Portuguese, were a proxy force funded and armed by Apartheid South Africa, with US help, to destabilise the newly independent socialist country) produced conditions that may well be repeated across many regions in coming decades. When millions of people have insufficient food resources, are being driven from their homes by starvation and warfare (which go hand in hand and often create a horrific mutual feedback loop), then the structures necessary to create and nurture a revival of wildlife species cannot survive. Yes, let us celebrate the successes mentioned in this lecture, but let us also realise that if we cannot fix the bigger story then none of these sub-plots will have any long term future.

That was a fantastic lecture! Another informative, enjoyable talk hosted by the RI.

Great talk. Great upload!

Fantastic talk!! Thank you for the information!!

Great talk, although I did find myself hearing Toto's "Africa" every time he mentioned the Serengeti!

I would like his opinion on where we might concentrate resources beneficially elsewhere

I dispute those aspen are chewed at 40:38 it is the natural maturation of P. tremuloides exposed, perhaps occasionally rubbed and burned but not chewed. Elk are not browsers by choice, they are grazers. Furthermore in the grass in front of him shows plenty regeneration going on: cloning from the Aspen roots, especially when stressed. Possibly the elk are *overgrazing* the regen, which would give a similar result by altering predator population but may lead to increased wildfires with heavier loads of dead grass laying about particularly in early Spring - there is much more research to be done. If you see shredded aspen or willow bark, suspect the velvet being rubbed off antlers in early fall; if you see chewed (clear tooth-marks) suspect first the moose, occasionally a deer - especially the mule deer - it will almost always be juvenile bark on trees or branches less than 10 cm in diameter. Trust me, mature poplar bark is not a great food source, even if you go through the work of chewing through to the cambium.

I am thankful to you Sean

It took this guy about 10 minutes to tell us what his talk was about. I hope he's not disappointed when young people don't watch it! My knowledge of kids, and people generally, is if you haven't got them interested in the first 30 seconds you have missed the boat.

worth it to learn abt the keystone species

Very nice - I'll be buying this book.

Fascinating topic and good storytelling.

Excellent lecture!

This is an awesomely educational video. Very good !

Excellent and fascinating.

Wonderful presentation! So informative.

Wow loved this guys presentation style! Who is he? The new David Attenborough! Thoroughly enjoyed this.

excellent lecturer

great presentation

so many brilliant Sean Carrolls

I had almost forgotten how rare good news was and how much I enjoy it until seeing this video. Great to see something positive working out, much less even undertaken, these days!

Time well spent ;)

This was excellent!

My summary: context history of the serengeti examples for the rules Trophic cascade: When one species has a chain reaction effect on the whole ecosystem, the chain reaction is called a trophic cascade. The number of animals can be regulated from the top down (by predators) or bottom up (by food) There are 4 rules: 1) There are some species which have a disproportionate effect on the diversity of creatures that live in a given place. They are called keystone species 2) Some species have strong indirect effects on other species through trophic cascades. 3) The regulation of some species depends on their density 4) Nature is incredibly resilient. If nature is given a chance, it can rebound dramatically

Very very interesting and encouraging.....Gracias

Incredible talk. Thank you

Excellent. Thank you.

What a great presentation. Entertaining and really informative. I just want to know when we will be hearing about the Everettian Multiverse. And what is that "B." In Sean's name? But for someone who has an interest in both environmental protection and cosmology coming across Sean B's presentation was a lovely piece of serendipity. Thanks!

very informative

Thank you!

Heartwarming. I just hope the African countries are able to keep these wildlife areas free of human development, given the stresses and challenges of climate change and population growth.

Thank you so much.

8:43- loses all credibility I take it back this was a great talk

Such insight.

Mr. Caroll is a joy to listen to and an awesome human being. That said, there is one thing that threw me off here. After spending a good bit of time describing how disease was the primary factor in animal populations and habitat viability on the Serengeti, at 33:10 he throws up a slide that only lists predation and food as factors. I don't want to be critical but nature is miraculously complicated and when we oversimplify our view of the many moving pieces, we often distort the big picture. This was a wonderful lecture that really made me think and taught me a lot. It also left me with optimism and a resolve to be respectful of nature and the planet as a whole.

Brilliant!

I loved this presentation

Excellent!

Growing up in Frankfurt, Germany in the 1950s, the Gzrimek's were of course a household name, and visiting the Zoo at least once a year, that Bernhard G. managed, was almost obligatory. His movies and shows at the ARD TV channel were regularly watched, and often presented in the Frankfurt schools. I guess we knew as schoolkids more about the Serengeti and its animals than our German habitats and wildlife.

This lecture does not bode well for the Monsanto approach to pst control. Investors you are warned

Excellent video

I don't know why he is called an 'evolutionary biologist', because there was very little mention of evolution (regardless of what might be inferred). It was a very good presentation. Apart from anthropomorphising nature, everything was pretty much pure biology. Well done!

Worth watching

I don't agree with everything, but this is a valuable video.

He mentioned not paving the road or making it bigger. How do I help keep people tame from doing to much?

Is the Serengeti rule applicable on Humanity and groups of humanity? Maybe on countries and groups in the country and in the workplace and maybe even in ones family? Are there Keystone humans and Groups of Humans?

As a young biologist I studied top down and bottom up effects in northern Norway in the 90ies. In the mountains. Bioproductivity had a huge effect. In the valleys there was an abundance of plants, feeding alot off herbivores (rodents, grouse), feeding predators. There you see a typical top down effect. Higher up in the slopes the productivity was lower. Held back by nutrients and climate. So low the area couldn't feed predators permanently. They would walk trough the area and prey some rodents, but it did not effect the numbers. Adding food showed an increase in numbers of rodents in the high areas. Not in the valleys. There was food enough to feed the herbivores, but they were kept down by predators. But in the high areas the herbivores had an effect on the plants. They are much more protective with thorns and bad taste. If everybody is out to eat you, the most protected species will thrive. Whithout herbivores in the high areas the shrubbs took over, If they were too many only grass could live. Those effects was not that visible in the productive valleys. In extreme hights, when the land cannot feed even herbivores, plants put everything into addapt to the elements. The world is green, yellow and white. In Serengetti (green) there are all trophic layers, and on small preys there is a top down effect. But for some species it is a green desert. It looks like it's alot of food, but for them it is not. They are living in a green desert.

Brilliant

Beautiful

Thanks The Royal Institution.☺

The wolf is also a very important species. Reintroduction has been very controversial due to predation on lifestock, but the effect on the wild has been positive as outlined by the presenter. Wolves prey on deer for example. By regulating the deer population some suppressed species of plants have been able to regain a foothold and help restore habitats. With an ever-growing human population we need to continue to find ways to reduce our impact on our planet. Pollution such as lack of proper waste management in many parts of the world, the unnecessary use of plastics and so on is something we need and can address. It will make our lives better as well by creating jobs and a more healthy population. Great presentation here. I like how he presents the data. Reminds me of a great biology teacher I had back in high school. Science rocks. Nature is resilient, but only if we as humans treat it is a gift to treasured. That we do not kill off species before even having discovered them. It is nice to see that we humans are not only able to consume and destroy, but also replace and regrow. Let us do more of that. I definitely want to be part of that esp. when it comes to finding ways on how to help humans live in harmony with the land.

The "perfect" science story always ties back to how great vaccines are.

So glad I watched this. It makes me realize the importance of stopping Climate Change. If we keep snipping the strands of the web of life eventually everything will collapse.

I would like to know where you went out on the safari .. even what company you used to take you on the safari ..

right now i'm digging the optical trick squares in the background . One moment you look at it its upside down, then again it goes right side up, and back n forth . 8:12 those statins are great but damn you get some screaming bad leg cramps in the middle of the night . my doctor took me off . but there must be something like say potassium rx which would minimize them so i could get back on the statins . i haven't had any blood work for a year and a half and im worried . got to find a new doctor i think

Thanks for this interesting talk.Any chance of an evolving keystone species to control the explosion of human kind causing so much of havoc on this small planet?

So Sean , vary inspiring talk to encourage an understanding of the relationships that keystone species have to the environment. I wonder what does the serengiti rules say about humanity. Does this natural rule imply that the human population should self regulate in the absence of predation and increased medical and scientific advances to prolong human life. It would also suggest that humans will eventually destroy our environment if populations increase beyond the available food and shelter available....

This is a great talk, but that video at 50 minutes _really_ needs a notch filter applied. That 5KHz tone is not pleasant to have to listen to at all =(

Wow!

Where do Carroll Quigley's brilliant prognostications fit into all this, Sean? He was Bubba's favorite prof/mentor at Georgetown and Clinton honored him at his 92 inauguration. @​

I wish he had circled back to the start of his lecture and talked about the trophic cascades that occur in human bodies when we introduce medicines on a long term basis; i.e. the chain of consequences that results when you follow the TV announcer's advice to "ask your doctor about" the latest immunomodulating drug.

Sean should also reveal long-term effects that would take much more than a few decades to study directly. Populations of a species that get very low reduce genetic diversity, making that species more vulnerable to extinction from simple causes, therefor more likely. It seems that he should add a 5th rule to address ecological dynamics over longer time-spans.

is this the Revoula estuary

Outstanding presentation. Fascinating!

This guy isn't a bad teacher...

AWESOME! So much for equality....

Yes nature is resilient leave it alone!

To enhance your experience in conjunction with the lecture the book, "What Evolution Is" by Ernst Mayer, is a go-to source for the understanding of gene pools and selection processes that is all around us.

true gold

The audience may be kids, but they are still probably more knowledgeable than most adults.

The Circle of Life is Amazing ....our respect to life dies day's is to low and we need to do more to keep life beautiful. Give Nature the Respect that it deserves, our own life's depend of it. KEEP the CIRCLE round .....and we all benefit from it....plain and simple, it is no magic, no hidden things, just respect life as all other things around you.