Joy of Science Experience the evolution of the Universe, Earth and Life

•  Review of last class •  Introduction

•  Contents of today’s lecture •  Quiz time

Unless otherwise noted, all pictures are taken from wikipedia.org

No class on June 3 due to Campus Festival

Review 1 n  The energy for the movement of tectonic plates comes from A. the Sun B. outer space C. the mantle D. the crust

Review 1 n  The energy for the movement of tectonic plates comes from A. the Sun B. outer space C. the mantle D. the crust

Review 2 n  A subduction zone is characteristic of A. a fault zone B. a transformed plate boundary C. a divergent plate boundary D. a convergent plate boundary

Review 2 n  A subduction zone is characteristic of A. a fault zone B. a transformed plate boundary C. a divergent plate boundary D. a convergent plate boundary

Review 3 n  The subsurface molten material in the mantle that enters a

volcano is called

A. crustal material B. fault flow C. magma d. lava

Review 3 n  The subsurface molten material in the mantle that enters a

volcano is called

A. crustal material B. fault flow C. magma d. lava

Review 4 n  A hot spot in the Earth’s crust is often associated with A. an oceanic ridge B. an oceanic trench C. a fault line D. a volcano

Review 4 n  A hot spot in the Earth’s crust is often associated with A. an oceanic ridge B. an oceanic trench C. a fault line D. a volcano

Strategies of Life All living things have own strategies to obtain and distribute energy, and then reproduce it

Today’s Keywords biology, taxonomy, Linnaean classification,

species, kingdoms, domains, Homo sapiens

Let us think about living things on Earth

n  What makes Earth different from all other places we know in the solar system (perhaps in the galaxy) is the existence of varied and abundant life

n  Despite the complexity, living things operate according to the same laws of nature as everything else we have studied

Ways of thinking about living things Let’s start thinking about living things with an example – an ant . An ant can be studied as n  an individual organism, n  a collection of specialized organs, n  a collection of cells, n  or, we could look deeper inside the cell and its ultimate constituents –

atoms and molecules.

Or, we may be interested in the bigger picture. n  An ant as part of an ant colony, n  An ant colony as part of an ecosystem of living and nonliving things, n  An ecosystem as part of the great global system on the planet.

Each approach complements and is complemented by the others.

What is Life? - The characteristics of life

1) All living things maintain a high degree of order and complexity : simplest living thing is more complex than any object constructed by humans. 2) All living things are part of larger systems of matter and energy : matter recycles in a given system, while energy flows through it. 3) All life depends on chemical reactions that take place in cells Cells: highly organized chemical building blocks of life 4) All life requires liquid water : water is an essential medium in the cells 5) Organisms grow and develop : forms and functions chage at different stages in their lifetime. 6) Living things regulate their use of energy and respond to their environments: :ex) animal’s hibernation, lowering body temperature by sweat evaporation 7) All living things share the same genetic code passed from parent to offspring by reproduction : a genetic code is written in the language of the molecule DNA. 8) All living things are descended from a common ancestor :many similarities among living things arise from their common ancestry.

n  Let’s have time to read through the textbook for today’s class subject

Introduction n  Biology: the study of living systems describing the great variety of organisms

on Earth

n  Taxonomy: the grouping of living things (organisms) according to similarities in structure and their distinctive characteristics

n  Five kingdoms: the broadest classification including 2 groups of single-celled organisms, fungi, plants, and animals

n  A species: the basic unit of classification, defined to be an interbreeding population

n  A given species is specialized in groups from most general to most specific. à phylum à class à order à family à genus à

n  (Linnaean) Classification of Humans :Animalia à Phylum:Chordata à Class:Mammalia à Order:Primates à Family:Hominidae à Genus:Homo à :sapiens

Introduction n  Biology: the study of living systems describing the great variety of organisms

on Earth

n  Taxonomy: the grouping of living things (organisms) according to similarities in structure and their distinctive characteristics

n  Five kingdoms: the broadest classification including 2 groups of single-celled organisms, fungi, plants, and animals

n  A species: the basic unit of classification, defined to be an interbreeding population

n  A given species is specialized in groups from most general to most specific. kingdom à phylum à class à order à family à genus à species

n  (Linnaean) Classification of Humans Kingdom:Animalia à Phylum:Chordata à Class:Mammalia à Order:Primates à Family:Hominidae à Genus:Homo à Species:sapiens

Cataloging Life – classifying living things

n  Taxonomy: the scientific process of classifying things and arranging them into groups

à Classification provides not only a ways of describing our world but also frameworks to fit new objects and phenomena into them n  Linnaean classification (by Carolus Linnaeus or Carl von Linné) : the most successful systematic classification scheme to group all living things according to their similar characters or differences à Linnean classification is not only describing species but also placing them into a hierarchy: a sequence of categories n  Main categories from broadest to narrowest are, kingdom, phylum, class, order, family, genus and species

Cataloging Life – five kingdoms

n  Kingdoms: the broadest classification Single-celled organisms 1. Monera: Single-celled organisms without a cell nucleus Ex) bacteria, blue-green bacteria (cyanobacteria) 2. Protista: Mainly single-celled with a cell nucleus and a few multicellular organisms with simple structure Ex) amoeba, euglena, some algae Multicellular organisms with different kinds of interdependent cells, distinguished primarily by energy obtaining methods 3. Fungi: absorbing materials from their environments Ex)mushroom, mold, yeast, shelf/bracket fungus 4. Plants: directly from the Sun through photosynthesis Ex) muticellular algae, mosses, flowering plants, trees 5. Animals: by eating other organisms Ex) sponge, jellyfish, insect, fish, frog, bird,…, man

A Different Division of Life - three domains of life

n  From the study of molecular genetics, a dramatically new division of life was proposed into three distinct domains of life.

1. Single-celled life without nucleus (all organisms in the Monera kingdom) * domain Bacteria * domain Archaea 2. All the other living things: all life based on cells with nuclei (kingdoms of protista, fungi, plants, and animals) * domain Eucaryea è Implies all life in kingdoms of protista, fungi, plants, and animals are chemically and genetically similar to each other

Simple diagram of 5 kingdoms & 3 domains of life

life Kingdom Bacteria

Kingdom Archaea

Kingdom Prostista

Kingdom Fungi

Kingdom Plants

Kingdom Animals

Domain Bacteria

Domain Archaea

Domain Eukaryea

Kingdom Monera

Classifying Human Beings A member of the kingdom of Animals動物界 Phylum chordates脊索動物門: thickened set of nervous down their back Subphylum vertebrates脊椎動物亜門: backbones Class mammals哺乳綱: hair, constant body temperature, nursing young Order primates霊長目: grasping fingers, eyes at front of head, large brain Family hominidヒト科: primates who walk erect Genus Homoヒト属: modern humans and closely related with them. All other species are extinct except Homo sapiens. Species H. sapiensサピエンス種: only One human species Race is classification of humans

Different species members in a genus group

n  Example of two different species from a common genus Polar bear (Ursus maritimus) Grizzly bear (Ursus horribilis) * A species is defined to be an interbreeding population, however hybrids between two different species are occasionally, even in the wild, possible.

* The hybrids between a polar bear and a grizzly bear are called pizzly (or prizzly) bear and grolar bear.

Implication of Linnaean Classification n  Implication from the fact that living things can be grouped in

successive layers so that a kind of family tree can be formed è all living things perhaps descended from the same primordial ancestor èQ: what makes the amount of similarities or difference between two organisms? A: the amount of time and rate of change because the two share a common ancestor. (The chapter of Evolutions of Life) n  Indeed, each classification group results from real events in the

past when species split off from each other

a common ancestor?

Next class is about, n Molecules of Life: p. 252 – p. 258

www.sci.hokudai.ac.jp/~epark/ekpark_e.html