Avsnitt
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Learn the key concepts in ecology and what makes populations change over time, with Professor Lindsay Turnbull from the University of Oxford Ecology is the study of plants and animals in their environments but what kinds of questions do ecologists try to answer? We begin with a population - a group of organisms belonging to the same species that live in one place. Some populations are stable, while others boom and bust, and we find out why births and deaths are key to understanding stability. We then consider why there are so many species on Earth and in doing so discover the ecological niche that constrains organisms to a specific role. Finally, we take a quick look at humans, who have broken out of their niche and taken control of the planet.
Erratum - Mammal biomass on Earth
The figures given in the video are incorrect. The actual figures are: 34% humans, 62% livestock and 4% wild mammals.
https://ourworldindata.org/wild-mammals-birds-biomass
Timestamps:
00:00 Intro
00:20 Titles
00:29 Key ecological questions
01:18 The state of populations: births and deaths
02:58 The rabbit versus the albatross
04:32 Keystone species: the case of the sea otter
06:20 Competition: the ecological niche
08:23 Humans – the ultimate competitor?
11:26 Outro -
Plants are awesome, with photosynthesis being the most disruptive invention ever! Join Professor Lindsay Turnbull from the University of Oxford to understand why Plants don't have faces, so we don't know what they're thinking, and can even (horror!) write them off as boring. In this video, we examine the evolutionary history of the land plants: from an ancestral alga to the diversity of modern flowering plants that cover our planet today. We will see how plants stole the technology for photosynthesis - undoubtedly the most disruptive invention of all time - and how their activities changed the biosphere forever. Finally, we explore the range of features that allow a large tree in full leaf to suck up a tonne of water every day.
Image Credit:
Many thanks to the Oxford Herbarium for providing the slides and microscope images of the Rhynie Cherts.
Atmospheric Carbon Dioxide Concentration Graph: NOAA Global Monitoring Lab, https://www.climate.gov/media/15554 (10/11/23)
Timestamps:
00:00 Intro
00:22 Titles
00:29 The Tragedy of Plants
01:13 What Makes a Plant a Plant
03:01 The Greatest Heist of All Time - Photosynthesis
04:13 The Rhynie Cherts - Early Land Plants
06:37 How Plants Regulate Our Climate
07:24 How We Have Broken Our Climate
08:45 Colour and Beauty - The Flowering Plants
09:59 Outro -
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Take a guided tour of the biology and ancestry of the vertebrates with Professor Lindsay Turnbull from the University of Oxford Want to know more about the group of animals you belong to - the vertebrates - and how we are all descendants of a plucky fish that hauled itself onto land? In this video we discover the fishy ancestor of the vertebrates: a type of lobe-finned fish, which are extremely rare in today's oceans.
We then explore biological scaling rules, which explain why small animals, like mice or hamsters, seem almost bionic when compared to a ponderous giant like an elephant. But vertebrates are all large animals, and their bodies must deliver oxygen and glucose to muscles buried deep within them. This has led to the evolution of some ingenious engineering solutions, like the vertebrate circulatory system.
Timestamps:
00:00 Intro
00:19 Titles
00:24 Who are the Vertebrates?
02:01 Fishy Origins
03:31 How Fish made it onto Land
04:34 The Circulatory System - A Vertebrate Invention
06:20 How Animals Get Large
07:51 Why Animals Get Large
09:28 Why the Vertebrates Left the Seas
09:59 Outro -
Take a whistle-stop tour of the Animal Kingdom with Professor Lindsay Turnbull from the University of Oxford Everyone can name a few animals - but did you know that most familiar animals only come from one group - and there's more than 30 to choose from?! In this video we discover the probable ancestor of the animals - a strange type of eukaryotic cell that fed on bacteria. But around 540 million years ago the animals experienced a burst of creativity, and a whole range of different animals sprang into being in the blink of a geological eye. We take a look at a few of the major groups - including arthropods, annelid worms and molluscs - which all play host to thousands of species.
Image Credit:
Cartwright et al (2007), Exceptionally Preserved Jellyfishes from the Middle Cambrian
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0001121
Timestamps:
00:00 Intro
00:14 Titles
00:18 When the Animals Go Marching
02:01 What Makes an Animal an Animal?
04:17 The Jelly Animals
06:00 How Muscles Have Evolved
07:45 Lines of Symmetry
09:48 Chordates - How Our Ancestor Evolved
11:33 Outro -
Explore the mysterious origins of the cells all multicellular organisms are made from - eukaryotic cells - with Professor Lindsay Turnbull from the University of Oxford Everyone sometimes thinks they're special, but have you ever learned the truth of how special the cells in your body are? In this video we discover the 'ancient ones', a group of cells called the archaea, and the special role they play in the evolution of eukaryotes. Eukaryotic cells are generally large and full of internal structures, called organelles, one of which, the famous mitochondria, isn't quite what it seems. Finally, we look how slime moulds can gang up when conditions are right, giving us a glimpse of how true multicellularity evolved.
Links to material used in this video:
Rogers et al. (2012) The Discovery of New Deep-Sea Hydrothermal Vent Communities in the Southern Ocean and Implications for Biogeography
https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1001234
Imachi et al. (2020) Isolation of an archaeon at the prokaryote–eukaryote interface. Nature 577, 519–525 (2020). https://doi.org/10.1038/s41586-019-19...
Image credit: Hiroyuki Imachi, Masaru K. Nobu,Nozomi Nakahara,Yuki Morono, Miyuki Ogawara, Yoshihiro Takaki, Yoshinori Takano, Katsuyuki Uematsu, Tetsuro Ikuta, Motoo Ito, Yohei Matsui, Masayuki Miyazaki, Kazuyoshi Murata, Yumi Saito, Sanae Sakai, Chihong Song, Eiji Tasumi, Yuko Yamanaka, Takashi Yamaguchi, Yoichi Kamagata, Hideyuki Tamaki, and Ken Takai
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
https://creativecommons.org/licenses/by-sa/4.0/deed.en
Timestamps:
00:00 Intro
00:17 Titles
00:22 Bacteria and Eukaryotes
01:44 The Ancient Ones
03:05 Inside Eukaryotes
06:02 The Mysteries of the Mitochondria
07:32 How Eukaryotes (probably) Evolved
09:33 Multicellularity in Eukaryotes
10:50 Outro -
Learn about the microbiome, the amazing flexibility of bacteria, and why we have an antibiotic resistance crisis with Professor Lindsay Turnbull from the University of Oxford Have you ever wondered what bacteria do for you? Bacteria are the ultimate survivors and brilliant at adapting to a changing environment. By turning genes on and off - known as gene expression - they can change the tools and machinery that they produce, so they can deal with different foodstuffs.
Bacteria also carry extra bits of DNA, called plasmids, that carry genes that allow bacteria to cope with unusual situations. Genes for antibiotic resistance are often carried on plasmids and this means they can easily be passed around, leading to the current crisis.
Timestamps:
00:00 Intro
00:24 Titles
00:29 The Microbiome
01:51 E.coli and gene expression
03:34 Gene expression in detail (the lac operon)
04:53 Plasmids and the antibiotic resistance crisis
06:49 Antibiotic use in livestock
08:30 What bacteria can't do
09:05 Outro -
Learn how cells generate energy by harnessing chemical reactions, with Professor Lindsay Turnbull from the University of Oxford Cells need energy to run their activities, which they obtain by harnessing chemical reactions. Join Lindsay Turnbull from the University of Oxford as she explains how one reaction - aerobic respiration - is perfect for supporting the energy-demanding lifestyles of active animals, like us.
Aerobic respiration ultimately relies on a chemical reaction between oxygen and hydrogen. This reaction is so explosive that humans used it to launch a rocket into space, but the cell mostly needs much smaller amounts of energy. Find out how cells have tamed this reaction by using it to turn a molecular turbine. The turbine then re-charges small molecular 'batteries', called ATP, which can deliver energy all around the cell.
Timestamps:
00:00 Intro
00:21 Titles
00:27 Life and the Laws of Thermodynamics
01:32 How life harnesses chemical reactions
03:50 Are cells like rockets?
04:45 How cells generate energy
06:57 Aerobic respiration
08:01 Photosynthesis
09:58 Outro -
Almost all species use sex to reproduce, but biologists struggle to understand why; join Professor Lindsay Turnbull from the University of Oxford as she explains the costs and benefits Sex puzzles biologists because it has a profound cost. Asexual species can potentially grow their populations much faster and so should outcompete their sexual cousins. But sexual species also produce genetically variable offspring - and in a changing environment, this can help them to stay ahead.
Sex also allows individuals within the same species to exchange genetic information, but they can't do this with members of other species. This genetic isolation allows species to follow separate evolutionary paths. These paths can be retraced by biologists using genome sequencing to build a tree of life.
Timestamps:
00:00 Intro
00:16 Titles
00:21 What exactly is sex?
02:22 Fertilisation explained
03:54 Sex in brief - recap
04:21 The problem - The Cost of Sex
05:42 So what is the point of sex?
08:15 How does sex create different species
10:30 Outro -
Learn the theory of evolution in a simpler, more intuitive way than ever before with Professor Lindsay Turnbull from the University of Oxford Evolution is the most important concept in biology. Beginning with the Peppered Moth, we look at the theory of evolution by natural selection in greater detail, looking at the three crucial assumptions on which it rests. Evolution has caused animals and plants to change dramatically over time, and we take a brief tour of the history of life on Earth - beginning with the first animals in the Palaeozoic, through dinosaurs in the Mesozoic, and finally mammals and birds in the Cenozoic.
Photo credit: photo of Mary Anning statue is thanks to Mary Anning Rocks (registered charity number: 1188919). Website: https://www.maryanningrocks.co.uk/
Timestamps:
00:00 Intro
00:20 Titles
00:25 The Peppered Moth
01:21 Adaptations to a changing environment
03:23 Darwin and Wallace
04:09 Theory of Evolution by Natural Selection
06:21 Mary Anning and the fossil record
07:39 The Age of the Earth
08:32 The Eon of Visible Life
11:00 Outro -
Learn how cells use the information in DNA and the key components that make up a cell, with Professor Lindsay Turnbull from the University of Oxford All cells share a core set of features that allow them to process information, which is the best way to start studying cells. Join Professor Lindsay Turnbull from the University of Oxford, as she explains these core features using unique illustrations and simple, engaging language.
Learn the fundamentals of every cell on Earth, including key cell components and their functions. Explore the different molecules of life from DNA to proteins and find out how errors in the genetic code lead to genetic disorders and lay the groundwork for evolution.
Timestamps:
00:00 Intro
00:13 Titles
00:18 Why do cells need information?
01:05 Diagram of information flow
02:32 Cell components in detail
04:52 Protein formation and properties
07:09 Mutation and genetic disorders
09:24 Evolution
10:24 Outro
